def __init__(self, file_num):

        self.file_num = file_num
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)

        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")

        self.packet =[0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 
                      0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D,
                      0x3E, 0x3F, 0x78]

        self.rssi_data = []
        self.packet_count = 0
    def _init_io(self):
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)
        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")
Example #3
0
    def _init_io(self):
        """
        Initialize I/O.

        This function initializes the radio I/O, including SPI, GPIO,
        and IRQ line.
        """        
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)
        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")
Example #4
0
    def __init__(self, file_num):

        self.file_num = file_num
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)

        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")

        self.packet = [
            0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A,
            0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x78
        ]

        self.rssi_data = []
        self.packet_count = 0
Example #5
0
    def _init_io(self):
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)
        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")
Example #6
0
    def _init_io(self):
        """
        Initialize I/O.

        This function initializes the radio I/O, including SPI, GPIO,
        and IRQ line.
        """
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)
        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")
class RF(object):
    def __init__(self, file_num):

        self.file_num = file_num
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)

        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")

        self.packet =[0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 
                      0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D,
                      0x3E, 0x3F, 0x78]

        self.rssi_data = []
        self.packet_count = 0

    def setup_rf(self, fc, hbsel, fb):
        spi.write(0x07, 0x80)           # reset all the registers
        spi.write(0x05, 0x00)           # Disable interrupts in IntStatReg1
        spi.write(0x06, 0x00)           # Disable interrupts in IntStatReg2

        spi.write(0x07, 0x01) 		# Set READY mode
        spi.write(0x09, 0x7F) 		# Cap = 12.5pF
        spi.write(0x0A, 0x05) 		# Clk output is 2MHz
        spi.write(0x0B, 0xF4) 		# GPIO0 is for RX data output
        spi.write(0x0C, 0xEF) 		# GPIO1 is TX/RX data CLK output
        spi.write(0x0D, 0x00) 		# GPIO2 for MCLK output
        spi.write(0x0E, 0x00) 		# GPIO port use default value
        spi.write(0x0F, 0x70) 		# NO ADC used
        spi.write(0x10, 0x00) 		# no ADC used
        spi.write(0x12, 0x00) 		# No temp sensor used
        spi.write(0x13, 0x00) 		# no temp sensor used
        spi.write(0x70, 0x0C) 		# No manchester code, no data whiting, data rate < 30Kbps
        spi.write(0x1C, 0x8A) 		# IF filter bandwidth
        spi.write(0x1D, 0x40) 		# AFC Loop
        spi.write(0x20, 0x60) 		# clock recovery
        spi.write(0x21, 0x01) 		# clock recovery
        spi.write(0x22, 0x55) 		# clock recovery
        spi.write(0x23, 0x55) 		# clock recovery
        spi.write(0x24, 0x02) 		# clock recovery timing
        spi.write(0x25, 0xAD) 		# clock recovery timing
        spi.write(0x2C, 0x40) 
        spi.write(0x2D, 0x0A) 
        spi.write(0x2E, 0x50) 
        spi.write(0x6E, 0x20) 		# TX data rate 1
        spi.write(0x6F, 0x00) 		# TX data rate 0
        spi.write(0x30, 0x8C) 		# Data access control
        spi.write(0x32, 0xFF) 		# Header control
        spi.write(0x33, 0x42) 		# Header 3, 2, 1, 0 used for head length,
                                        # fixed packet length, synchronize word length 3, 2,
        spi.write(0x34, 64) 		# 64 nibble = 32 byte preamble
        spi.write(0x35, 0x20) 		# 0x35 need to detect 20bit preamble
        spi.write(0x36, 0x2D) 		# synchronize word
        spi.write(0x37, 0xD4) 
        spi.write(0x38, 0x00) 
        spi.write(0x39, 0x00) 
        spi.write(0x3A, 0xff) 		# set tx header 3
        spi.write(0x3B, 0xff) 		# set tx header 2
        spi.write(0x3C, 0xff) 		# set tx header 1
        spi.write(0x3D, 0xff) 		# set tx header 0
        spi.write(0x3E, 17) 		# set packet length to 17 bytes
        spi.write(0x3F, 0xff) 		# set rx header
        spi.write(0x40, 0xff) 
        spi.write(0x41, 0xff) 
        spi.write(0x42, 0xff) 
        spi.write(0x43, 0xFF) 		# check all bits
        spi.write(0x44, 0xFF) 		# Check all bits
        spi.write(0x45, 0xFF) 		# check all bits
        spi.write(0x46, 0xFF) 		# Check all bits
        spi.write(0x56, 0x01) 
        # spi.write(0x6D, 0x04) 		# Tx power to max
        spi.write(0x6D, 0x07) 		# Tx power to max
        spi.write(0x79, 0x00) 		# no frequency hopping
        spi.write(0x7A, 0x00) 		# no frequency hopping
        spi.write(0x71, 0x22) 		# GFSK, fd[8]=0, no invert for TX/RX data, FIFO mode, txclk-->gpio
        spi.write(0x72, 0xc8) 		# Frequency deviation setting to 45K=72*625
        spi.write(0x73, 0x00) 		# No frequency offset
        spi.write(0x74, 0x00) 		# No frequency offset

        val = 0x40 | hbsel << 5 | fb
        spi.write(0x75, val) 		# frequency set to 434MHz
        spi.write(0x76, fc >> 8) 		# frequency set to 434MHz
        spi.write(0x77, fc & 0xff) 		# frequency set to 434Mhz

        

        spi.write(0x5A, 0x7F) 
        spi.write(0x59, 0x60) 
        spi.write(0x58, 0x80) 
        spi.write(0x6A, 0x0B) 
        spi.write(0x68, 0x04) 
        spi.write(0x1F, 0x03)












        # spi.write(0x07, 0x80)           # reset all the registers
        # spi.write(0x05, 0x00)           # Disable interrupts in IntStatReg1
        # spi.write(0x06, 0x00)           # Disable interrupts in IntStatReg2

        # spi.write(0x07, 0x01) 		# Set READY mode
        # spi.write(0x09, 0x7F) 		# Cap = 12.5pF
        # spi.write(0x0A, 0x05) 		# Clk output is 2MHz
        # spi.write(0x0B, 0xF4) 		# GPIO0 is for RX data output
        # spi.write(0x0C, 0xEF) 		# GPIO1 is TX/RX data CLK output
        # spi.write(0x0D, 0x00) 		# GPIO2 for MCLK output
        # spi.write(0x0E, 0x00) 		# GPIO port use default value
        # spi.write(0x0F, 0x70) 		# NO ADC used
        # spi.write(0x10, 0x00) 		# no ADC used
        # spi.write(0x12, 0x00) 		# No temp sensor used
        # spi.write(0x13, 0x00) 		# no temp sensor used
        # spi.write(0x70, 0x20) 		# No manchester code, no data whiting, data rate < 30Kbps
        # spi.write(0x1C, 0x1D) 		# IF filter bandwidth
        # spi.write(0x1D, 0x40) 		# AFC Loop
        # spi.write(0x20, 0xA1) 		# clock recovery
        # spi.write(0x21, 0x20) 		# clock recovery
        # spi.write(0x22, 0x4E) 		# clock recovery
        # spi.write(0x23, 0xA5) 		# clock recovery
        # spi.write(0x24, 0x00) 		# clock recovery timing
        # spi.write(0x25, 0x0A) 		# clock recovery timing
        # spi.write(0x2C, 0x00) 
        # spi.write(0x2D, 0x00) 
        # spi.write(0x2E, 0x00) 
        # spi.write(0x6E, 0x27) 		# TX data rate 1
        # spi.write(0x6F, 0x52) 		# TX data rate 0
        # spi.write(0x30, 0x8C) 		# Data access control
        # spi.write(0x32, 0xFF) 		# Header control
        # spi.write(0x33, 0x42) 		# Header 3, 2, 1, 0 used for head length,
        #                                 # fixed packet length, synchronize word length 3, 2,
        # spi.write(0x34, 64) 		# 64 nibble = 32 byte preamble
        # spi.write(0x35, 0x20) 		# 0x35 need to detect 20bit preamble
        # spi.write(0x36, 0x2D) 		# synchronize word
        # spi.write(0x37, 0xD4) 
        # spi.write(0x38, 0x00) 
        # spi.write(0x39, 0x00) 
        # spi.write(0x3A, 0xff) 		# set tx header 3
        # spi.write(0x3B, 0xff) 		# set tx header 2
        # spi.write(0x3C, 0xff) 		# set tx header 1
        # spi.write(0x3D, 0xff) 		# set tx header 0
        # spi.write(0x3E, 17) 		# set packet length to 17 bytes
        # spi.write(0x3F, 0xff) 		# set rx header
        # spi.write(0x40, 0xff) 
        # spi.write(0x41, 0xff) 
        # spi.write(0x42, 0xff) 
        # spi.write(0x43, 0xFF) 		# check all bits
        # spi.write(0x44, 0xFF) 		# Check all bits
        # spi.write(0x45, 0xFF) 		# check all bits
        # spi.write(0x46, 0xFF) 		# Check all bits
        # spi.write(0x56, 0x01) 
        # spi.write(0x6D, 0x07) 		# Tx power to max
        # spi.write(0x79, 0x00) 		# no frequency hopping
        # spi.write(0x7A, 0x00) 		# no frequency hopping
        # spi.write(0x71, 0x22) 		# GFSK, fd[8]=0, no invert for TX/RX data, FIFO mode, txclk-->gpio
        # spi.write(0x72, 0x48) 		# Frequency deviation setting to 45K=72*625
        # spi.write(0x73, 0x00) 		# No frequency offset
        # spi.write(0x74, 0x00) 		# No frequency offset

        # val = 0x40 | hbsel << 5 | fb
        # spi.write(0x75, val) 		# frequency set to 434MHz
        # spi.write(0x76, fc >> 8) 		# frequency set to 434MHz
        # spi.write(0x77, fc & 0xff) 		# frequency set to 434Mhz

        # # spi.write(0x75, 0x53) 		# frequency set to 434MHz
        # # spi.write(0x76, 0x64) 		# frequency set to 434MHz
        # # spi.write(0x77, 0x00) 		# frequency set to 434Mhz
        # spi.write(0x5A, 0x7F) 
        # spi.write(0x59, 0x40) 
        # spi.write(0x58, 0x80) 
        # spi.write(0x6A, 0x0B) 
        # spi.write(0x68, 0x04) 
        # spi.write(0x1F, 0x03)

        

    def clear_tx_fifo(self):
        spi.write(0x08, 0x01)
        spi.write(0x08, 0x00)


    def clear_rx_fifo(self):
        spi.write(0x08, 0x02)
        spi.write(0x08, 0x00)


    def clear_fifo(self):
        spi.write(0x08, 0x03)
        spi.write(0x08, 0x00)


    def clear_interrupt(self):
        i = spi.read(0x03)    
        i = spi.read(0x04)


    def set_rx_fifo_almost_full_threshold(self, threshold):
        spi.write(0x7E, threshold)


    def set_tx_fifo_almost_full_threshold(self, threshold):
        pass


    def read_rx_fifo(self):
        return spi.read(0x7F)




    def set_rfm22_state(self, rfm22_state):
        if rfm22_state == 'tx':
            spi.write(0x07, 0x09)

        elif rfm22_state == 'rx':
            spi.write(0x07, 0x05)

        else:
            pass


    def set_rfm22_mode(self, mode):
        if mode == 'ready':
            spi.write(0x07, 0x01)

        elif mode == 'tune':
            spi.write(0x07, 0x03)

        else:
            pass


    def enable_interrupt(self, signal):
        reg_1 = spi.read(0x05)
        reg_2 = spi.read(0x06)
        if signal == 'valid_packet_received':
            spi.write(0x05, reg_1 | 0x02)
        else:
            print "error in enable_interrupt"
        

    def module_power_state(self):
        status = spi.read(0x02)
        power_state = status & 0x03
        if power_state == 0x00:
            return 'idle'
        elif power_state == 0x01:
            return 'rx'
        elif power_state == 0x02:
            return 'tx'
        else:
            print "error in module_power_state"
        


    def receive(self):
        self.set_rfm22_mode('ready')

        # is there any particular order these should be in?
        self.set_rx_fifo_almost_full_threshold(17)
        self.tx_ant.write(0)
        self.rx_ant.write(1)
        self.clear_interrupt()
        self.clear_fifo()
        self.set_rfm22_state('rx')
        self.enable_interrupt('valid_packet_received')
        print "RSSI Threshold: ", '{0:d}'.format(spi.read(0x27))
        print "RSSI Indicator: ", '{0:d}'.format(spi.read(0x26))



        print "receiving packet..."
        while self.module_power_state() == 'rx':
            result = self.irq.read()
            rssi = '{0:d}'.format(spi.read(0x26))
            self.rssi_data.append([time.time(), rssi])
            # print "RSSI Indicator: ", rssi
            # print "interrupt: ", int(result)
            if ( int(result) == 0 ):
                rx_buffer = []

                for i in range(17):
                    rx_buffer.append(self.read_rx_fifo())

                if ( rx_buffer == self.packet ):
                    print "Packet Received"
                    self.packet_count += 1

                







    




    def _fsm(self, fsm_state):

        while True:

            if fsm_state == 'idle':
                pass

            elif fsm_state == 'tx':
                pass

            elif fsm_state == 'rx':
                fc, hbsel, fb = freq_utils.carrier_freq(434e6)
                self.setup_rf(fc, hbsel, fb)
                self.receive()
                if self.packet_count == 50:
                    break
                else:
                    state = 'rx'
            else:
                pass


    def run(self):
        self._fsm('rx')


    def shutdown(self):
        self.close_gpio()

        f = open("rssi_data_" + self.file_num + '.txt','w')
        for i in self.rssi_data:
            f.write(str(i) + "\n")
        f.close()
        


    def close_gpio(self):
        self.tx_ant.close()
        self.rx_ant.close()
        self.irq.close()
Example #8
0
class RF(object):
    def __init__(self):
        self.rfm22 = RFM22()
        self.back_off = RandomBackOff()
        # self.rssi_threshold = 100

    def _init_io(self):
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)
        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")

    def _kill_io(self):
        self.tx_ant.close()
        self.rx_ant.close()
        self.irq.close()

    def _init_rf(self):
        self.rfm22.reset_all_registers()
        self.rfm22.disable_interrupts()
        self.rfm22.default_rf22_setup()

    def _listen(self, freq):
        self.rfm22.set_frequency(freq)
        self.rfm22.disable_interrupts()
        self.rfm22.set_op_mode('ready')
        self.tx_ant.write(0)
        self.rx_ant.write(1)
        self.rfm22.clear_rx_fifo()
        self.rfm22.clear_interrupts()
        self.rfm22.set_op_mode('rx')
        time.sleep(0.01)  # need a bit of time before we read rssi values
        rssi_level = float('{0:d}'.format(spi.read(0x26)))
        while (rssi_level >= 100):
            b = self.back_off.run()
            if (b == "continue"):
                continue
            else:  # (b == "break")
                keep_looping = False
                break

    def _receive(self, freq):
        time_out = Timer(2.0)
        ack = [
            0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
            0xff, 0xff, 0xff, 0xff, 0xff, 0xff
        ]
        self.rfm22.set_frequency(freq)
        self.rfm22.disable_interrupts()
        self.rfm22.set_op_mode('ready')
        self.tx_ant.write(0)
        self.rx_ant.write(1)
        self.rfm22.clear_rx_fifo()
        self.rfm22.clear_interrupts()
        self.rfm22.set_rx_fifo_almost_full_threshold(17)
        self.rfm22.enable_interrupt('valid_packet_received')
        self.rfm22.set_op_mode('rx')

        print "waiting for ACK..."
        r = self.irq.read()
        time_out.start()
        while (int(r) == 1):
            if time_out.timer_event.isSet():
                time_out.join()
                del (time_out)
                print "Time out exceeded"
                return
            else:
                r = self.irq.read()
        rx_buffer = []
        for i in range(17):
            rx_buffer.append(spi.read(0x7F))
        if (rx_buffer == ack):
            print "ACK Received"

    def _transmit(self, freq):
        data = [
            0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A,
            0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x78
        ]

        self.rfm22.set_frequency(freq)
        self.rfm22.disable_interrupts()
        self.rfm22.set_op_mode('ready')
        self.rx_ant.write(0)
        self.tx_ant.write(1)
        self.rfm22.clear_tx_fifo()
        self.rfm22.load_tx_fifo(data)
        self.rfm22.enable_interrupt('packet_sent')
        self.rfm22.clear_interrupts()
        self.rfm22.set_op_mode('tx')

        r = self.irq.read()
        while (int(r) == 1):
            r = self.irq.read()
        print "packet sent"

        self.rx_ant.write(0)
        self.tx_ant.write(0)

    def run(self):
        pass

    def fsm(self):
        """
        Primary control loop.

        This function is the finite state machine that controls the
        operation of the system.
        """

        self._init_io()
        self._init_rf()

        state = "listen"
        f = 434e6

        while True:
            if state == "listen":
                self._listen(f)
                state = "transmit"

            elif state == "transmit":
                self._transmit(f)
                state = "receive"

            elif state == "receive":
                self._receive(f)
                state = "listen"

            else:
                print "+++ Melon melon melon +++"
                state = "listen"

    def shutdown(self):
        self._kill_io()
Example #9
0
class RadioAPI(object):
    """
    Radio API.

    This class implements the functionality and provides the tools
    for making radio applications.
    """

    def __init__(self):
        self.rfm22 = RadioBase()
        self.backoff = RandomBackOff()


    def _init_io(self):
        """
        Initialize I/O.

        This function initializes the radio I/O, including SPI, GPIO,
        and IRQ line.
        """        
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)
        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")



    def _kill_io(self):
        """
        Shutdown I/O.

        This function closes and ends the radio I/O including GPIO and
        IRQ line.
        """
        self.tx_ant.close()
        self.rx_ant.close()
        self.irq.close()



    def _init_rf(self):
        """
        Initialize RF.

        This function intitializes the RF parameters, resetting all
        RFM 22 registers, disabling all interrupts, and enabling a
        default configuration.
        """
        self.rfm22.reset_all_registers()
        self.rfm22.disable_interrupts()
        self.rfm22.default_setup()




    def _tx_rx_switch(self, mode):
        """
        Switch T/R mode.

        This function turns the transmit/receive switch to
        receive, transmit, or off.

        Parameters
        ----------
        mode : str
            Mode for T/R switch operation, one of `tx`, `rx`, or `off`.

        Raises
        ------
        KeyError
            if mode not in [`tx`, `rx`, `off`].
        """
        if mode not in ['tx', 'rx', 'off']:
            raise ValueError
        else:
            if mode == 'tx':
                self.rx_ant.write(0)
                self.tx_ant.write(1)
            elif mode == 'rx':
                self.tx_ant.write(0)
                self.rx_ant.write(1)
            elif mode == 'off':
                self.tx_ant.write(0)
                self.rx_ant.write(0)
            else:
                print "+++ Melon melon melon +++"

        

    def startup(self):
        """
        General radio initialization.

        This helper function initializes the I/O and RF.
        """
        self._init_io()
        self._init_rf()


    def shutdown(self):
        """
        General radio cleanup.

        This helper function cleans up and shuts down any open
        processes.
        """
        self._kill_io()


    def transmit(self, data, freq, DEBUG=True):
        """
        Transmit data packet. 

        This function takes data and loads it into the TX FIFO buffer for
        transmission over the air.

        Parameters
        ----------
        data : list
            Input list of data to be transmitted, each element of which is 8
            bits. Maximum list size is 64 elements.
        freq : float
            Operating (center) frequency for transmission.
        DEBUG : bool, optional
            Flag to turn on debug message printing .

        Raises
        ------
        IndexError
            if length of `data` is greater than 64.
        """
        if len(data) > 64:
            raise IndexError
        else:
            self.rfm22.set_op_mode('ready')

            self.rfm22.disable_interrupts()
            self.rfm22.clear_interrupts()
            self.rfm22.clear_tx_fifo()

            self.rfm22.set_frequency(freq)
            self.rfm22.load_tx_fifo(data)

            self._tx_rx_switch('tx')

            self.rfm22.enable_interrupt('packet_sent')
            self.rfm22.set_op_mode('tx')

            r = self.irq.read()
            while (int(r) == 1):
                r = self.irq.read()
            if DEBUG:
                print "packet sent"
                
            self._tx_rx_switch('off')
       





    def listen(self, freq, rssi_threshold=100, timeout=0.5, DEBUG=True):
        """
        Listen before talk.

        This function implements listen-before-talk or carrier
        sense. RSSI is used to determine if the frequency of interest
        is busy. Timeout is used to interrupt the listening process,
        returning a value of `busy` to the parent (calling) function.

        Parameters
        ----------
        freq : float
            Operating (center) frequency of interest.
        rssi_threshold : int, optional
            RSSI threshold for determining whether channel is clear. Default
            value is 100. This value is not a power value; for relationship
            between RSSI and power, see [RFM22].
        timeout : float, optional
            Timeout value in seconds.
        DEBUG : bool, optional
            Flag to turn on debug message printing.

        Returns
        -------
        out : str
            Frequency (channel) status, either `clear` or `busy`.

        References
        ----------
        .. [RFM22] Figure 31, pg 64, RFM22 Data sheet.
        """
        self.rfm22.set_op_mode('ready')

        self.rfm22.disable_interrupts()
        self.rfm22.clear_interrupts()
        self.rfm22.clear_rx_fifo()

        self.rfm22.set_frequency(freq)

        self._tx_rx_switch('rx')

        self.rfm22.set_op_mode('rx')


        time.sleep(0.01) # need a bit of time before we read rssi values

        rssi_level = float('{0:d}'.format(spi.read(0x26)))

        while (rssi_level >= 100):
            b = self.backoff.run()
            if (b == "continue"):
                rssi_level = float('{0:d}'.format(spi.read(0x26)))
                continue
            else: # (b == "break")
                self._tx_rx_switch('off')
                return 'busy'

        self._tx_rx_switch('off')
        return 'clear'



    def receive(self, freq, rx_fifo_threshold=17, timeout=None, DEBUG=True):
        """
        Receive data.

        This function receives data and does more stuff. TODO: Add
        more here. If `timeout` is none, then there is no time limit
        on how long to wait to receive a packet.

        Parameters
        ----------
        freq : float
            Operating (center) frequency of interest.
        rx_fifo_threshold : int, optional
            Value for RX Almost Full threshold. When the incoming RX data
            reaches the Almost Full Threshold an interrupt will be generated
            to the microcontroller via the nIRQ pin. The microcontroller
            will then need to read the data from the RX FIFO.
        timeout : float, optional
            Timeout value in seconds. Default value is 120.
        DEBUG : bool, optional
            Flag to turn on debug message printing.

        Returns
        -------
        rx_buffer : list
            Received data, from RX FIFO buffer.
        """
        self.rfm22.set_op_mode('ready')

        self.rfm22.disable_interrupts()
        self.rfm22.clear_interrupts()
        self.rfm22.clear_rx_fifo()

        self.rfm22.set_frequency(freq)
        self.rfm22.set_rx_fifo_almost_full_threshold(rx_fifo_threshold)

        self._tx_rx_switch('rx')

        self.rfm22.enable_interrupt('valid_packet_received')
        self.rfm22.set_op_mode('rx')


        if timeout == None:
            if DEBUG:
                print "waiting for packet..."
            r = self.irq.read()
            while (int(r) == 1): # interrupt is driven low when packet arrives
                r = self.irq.read()

            rx_buffer = []
            for i in range(rx_fifo_threshold):
                rx_buffer.append(spi.read(0x7F))
            return rx_buffer

        else:
            timer=Timer(timeout)
            timer.start()
            if DEBUG:
                print "waiting for packet..."
            r = self.irq.read()
            while (int(r) == 1): # interrupt is driven low when packet arrives
                if timer.flag.isSet():
                    timer.join()
                    del(timer)
                    if DEBUG:
                        print "Time out exceeded"                
                    return []
                else:
                    r = self.irq.read()
            # timer.join() # this doesn't seem necessary, and it takes
                           # a long time to execute BigO(1 sec) 
            # del(timer)
            rx_buffer = []
            for i in range(rx_fifo_threshold):
                rx_buffer.append(spi.read(0x7F))
            return rx_buffer




    



    def configure_radio(self, power = 17, frequency = 434e6, data_rate = 4.8e3, modulation = "gfsk"):
        """
        Configure radio.

        This function configures the radio for transmit and receive operation.

        Parameters
        ----------
        power : int
            Output power in dBm, one of {8 | 11 | 14 | 17}.
        frequency : float
            Center frequency, this should be between 240.0e6 and 930.0e6.
        data_rate : float

        modulation : str
            Modulation type, one of {'unmodulated' | 'ook' | 'fsk' | 'gfsk'}.        

        """
        self.rfm22.set_output_power(power)
        self.rfm22.set_frequency(frequency)
        self.rfm22.set_data_rate(data_rate)
        self.rfm22.set_modulation(modulation)
Example #10
0
class RadioAPI(object):
    """
    Radio API.

    This class implements the functionality and provides the tools
    for making radio applications.
    """
    def __init__(self):
        self.rfm22 = RadioBase()
        self.backoff = RandomBackOff()

    def _init_io(self):
        """
        Initialize I/O.

        This function initializes the radio I/O, including SPI, GPIO,
        and IRQ line.
        """
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)
        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")

    def _kill_io(self):
        """
        Shutdown I/O.

        This function closes and ends the radio I/O including GPIO and
        IRQ line.
        """
        self.tx_ant.close()
        self.rx_ant.close()
        self.irq.close()

    def _init_rf(self):
        """
        Initialize RF.

        This function intitializes the RF parameters, resetting all
        RFM 22 registers, disabling all interrupts, and enabling a
        default configuration.
        """
        self.rfm22.reset_all_registers()
        self.rfm22.disable_interrupts()
        self.rfm22.default_setup()

    def _tx_rx_switch(self, mode):
        """
        Switch T/R mode.

        This function turns the transmit/receive switch to
        receive, transmit, or off.

        Parameters
        ----------
        mode : str
            Mode for T/R switch operation, one of `tx`, `rx`, or `off`.

        Raises
        ------
        KeyError
            if mode not in [`tx`, `rx`, `off`].
        """
        if mode not in ['tx', 'rx', 'off']:
            raise ValueError
        else:
            if mode == 'tx':
                self.rx_ant.write(0)
                self.tx_ant.write(1)
            elif mode == 'rx':
                self.tx_ant.write(0)
                self.rx_ant.write(1)
            elif mode == 'off':
                self.tx_ant.write(0)
                self.rx_ant.write(0)
            else:
                print "+++ Melon melon melon +++"

    def startup(self):
        """
        General radio initialization.

        This helper function initializes the I/O and RF.
        """
        self._init_io()
        self._init_rf()

    def shutdown(self):
        """
        General radio cleanup.

        This helper function cleans up and shuts down any open
        processes.
        """
        self._kill_io()

    def transmit(self, data, freq, DEBUG=True):
        """
        Transmit data packet. 

        This function takes data and loads it into the TX FIFO buffer for
        transmission over the air.

        Parameters
        ----------
        data : list
            Input list of data to be transmitted, each element of which is 8
            bits. Maximum list size is 64 elements.
        freq : float
            Operating (center) frequency for transmission.
        DEBUG : bool, optional
            Flag to turn on debug message printing .

        Raises
        ------
        IndexError
            if length of `data` is greater than 64.
        """
        if len(data) > 64:
            raise IndexError
        else:
            self.rfm22.set_op_mode('ready')

            self.rfm22.disable_interrupts()
            self.rfm22.clear_interrupts()
            self.rfm22.clear_tx_fifo()

            self.rfm22.set_frequency(freq)
            self.rfm22.load_tx_fifo(data)

            self._tx_rx_switch('tx')

            self.rfm22.enable_interrupt('packet_sent')
            self.rfm22.set_op_mode('tx')

            r = self.irq.read()
            while (int(r) == 1):
                r = self.irq.read()
            if DEBUG:
                print "packet sent"

            self._tx_rx_switch('off')

    def listen(self, freq, rssi_threshold=100, timeout=0.5, DEBUG=True):
        """
        Listen before talk.

        This function implements listen-before-talk or carrier
        sense. RSSI is used to determine if the frequency of interest
        is busy. Timeout is used to interrupt the listening process,
        returning a value of `busy` to the parent (calling) function.

        Parameters
        ----------
        freq : float
            Operating (center) frequency of interest.
        rssi_threshold : int, optional
            RSSI threshold for determining whether channel is clear. Default
            value is 100. This value is not a power value; for relationship
            between RSSI and power, see [RFM22].
        timeout : float, optional
            Timeout value in seconds.
        DEBUG : bool, optional
            Flag to turn on debug message printing.

        Returns
        -------
        out : str
            Frequency (channel) status, either `clear` or `busy`.

        References
        ----------
        .. [RFM22] Figure 31, pg 64, RFM22 Data sheet.
        """
        self.rfm22.set_op_mode('ready')

        self.rfm22.disable_interrupts()
        self.rfm22.clear_interrupts()
        self.rfm22.clear_rx_fifo()

        self.rfm22.set_frequency(freq)

        self._tx_rx_switch('rx')

        self.rfm22.set_op_mode('rx')

        time.sleep(0.01)  # need a bit of time before we read rssi values

        rssi_level = float('{0:d}'.format(spi.read(0x26)))

        while (rssi_level >= 100):
            b = self.backoff.run()
            if (b == "continue"):
                rssi_level = float('{0:d}'.format(spi.read(0x26)))
                continue
            else:  # (b == "break")
                self._tx_rx_switch('off')
                return 'busy'

        self._tx_rx_switch('off')
        return 'clear'

    def receive(self, freq, rx_fifo_threshold=17, timeout=None, DEBUG=True):
        """
        Receive data.

        This function receives data and does more stuff. TODO: Add
        more here. If `timeout` is none, then there is no time limit
        on how long to wait to receive a packet.

        Parameters
        ----------
        freq : float
            Operating (center) frequency of interest.
        rx_fifo_threshold : int, optional
            Value for RX Almost Full threshold. When the incoming RX data
            reaches the Almost Full Threshold an interrupt will be generated
            to the microcontroller via the nIRQ pin. The microcontroller
            will then need to read the data from the RX FIFO.
        timeout : float, optional
            Timeout value in seconds. Default value is 120.
        DEBUG : bool, optional
            Flag to turn on debug message printing.

        Returns
        -------
        rx_buffer : list
            Received data, from RX FIFO buffer.
        """
        self.rfm22.set_op_mode('ready')

        self.rfm22.disable_interrupts()
        self.rfm22.clear_interrupts()
        self.rfm22.clear_rx_fifo()

        self.rfm22.set_frequency(freq)
        self.rfm22.set_rx_fifo_almost_full_threshold(rx_fifo_threshold)

        self._tx_rx_switch('rx')

        self.rfm22.enable_interrupt('valid_packet_received')
        self.rfm22.set_op_mode('rx')

        if timeout == None:
            if DEBUG:
                print "waiting for packet..."
            r = self.irq.read()
            while (int(r) == 1):  # interrupt is driven low when packet arrives
                r = self.irq.read()

            rx_buffer = []
            for i in range(rx_fifo_threshold):
                rx_buffer.append(spi.read(0x7F))
            return rx_buffer

        else:
            timer = Timer(timeout)
            timer.start()
            if DEBUG:
                print "waiting for packet..."
            r = self.irq.read()
            while (int(r) == 1):  # interrupt is driven low when packet arrives
                if timer.flag.isSet():
                    timer.join()
                    del (timer)
                    if DEBUG:
                        print "Time out exceeded"
                    return []
                else:
                    r = self.irq.read()
            # timer.join() # this doesn't seem necessary, and it takes
            # a long time to execute BigO(1 sec)
            # del(timer)
            rx_buffer = []
            for i in range(rx_fifo_threshold):
                rx_buffer.append(spi.read(0x7F))
            return rx_buffer

    def configure_radio(self,
                        power=17,
                        frequency=434e6,
                        data_rate=4.8e3,
                        modulation="gfsk"):
        """
        Configure radio.

        This function configures the radio for transmit and receive operation.

        Parameters
        ----------
        power : int
            Output power in dBm, one of {8 | 11 | 14 | 17}.
        frequency : float
            Center frequency, this should be between 240.0e6 and 930.0e6.
        data_rate : float

        modulation : str
            Modulation type, one of {'unmodulated' | 'ook' | 'fsk' | 'gfsk'}.        

        """
        self.rfm22.set_output_power(power)
        self.rfm22.set_frequency(frequency)
        self.rfm22.set_data_rate(data_rate)
        self.rfm22.set_modulation(modulation)
class RF(object):
    def __init__(self):
        self.rfm22 = RFM22()
        self.back_off = RandomBackOff()
        # self.rssi_threshold = 100


    def _init_io(self):
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)
        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")


    def _kill_io(self):
        self.tx_ant.close()
        self.rx_ant.close()
        self.irq.close()


    def _init_rf(self):
        self.rfm22.reset_all_registers()
        self.rfm22.disable_interrupts()
        self.rfm22.default_rf22_setup()


    def _listen(self, freq):
        self.rfm22.set_frequency(freq)
        self.rfm22.disable_interrupts()
        self.rfm22.set_op_mode('ready')
        self.tx_ant.write(0)
        self.rx_ant.write(1)
        self.rfm22.clear_rx_fifo()
        self.rfm22.clear_interrupts()
        self.rfm22.set_op_mode('rx')
        time.sleep(0.01) # need a bit of time before we read rssi values
        rssi_level = float('{0:d}'.format(spi.read(0x26)))
        while (rssi_level >= 100):
            b = self.back_off.run()
            if (b == "continue"):
                continue
            else: # (b == "break")
                keep_looping = False
                break



        
    def _receive(self, freq):
        time_out = Timer(2.0)
        ack = [0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
               0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
               0xff, 0xff, 0xff]
        self.rfm22.set_frequency(freq)
        self.rfm22.disable_interrupts()
        self.rfm22.set_op_mode('ready')
        self.tx_ant.write(0)
        self.rx_ant.write(1)
        self.rfm22.clear_rx_fifo()
        self.rfm22.clear_interrupts()
        self.rfm22.set_rx_fifo_almost_full_threshold(17)
        self.rfm22.enable_interrupt('valid_packet_received')
        self.rfm22.set_op_mode('rx')

        print "waiting for ACK..."
        r = self.irq.read()
        time_out.start()
        while (int(r) == 1):
            if time_out.timer_event.isSet():
                time_out.join()
                del(time_out)
                print "Time out exceeded"                
                return
            else:
                r = self.irq.read()
        rx_buffer = []
        for i in range(17):
            rx_buffer.append(spi.read(0x7F))
        if (rx_buffer == ack):
            print "ACK Received"




    def _transmit(self, freq):
        data = [0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 
                0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D,
                0x3E, 0x3F, 0x78]

        self.rfm22.set_frequency(freq)
        self.rfm22.disable_interrupts()
        self.rfm22.set_op_mode('ready')
        self.rx_ant.write(0)
        self.tx_ant.write(1)
        self.rfm22.clear_tx_fifo()
        self.rfm22.load_tx_fifo(data)
        self.rfm22.enable_interrupt('packet_sent')
        self.rfm22.clear_interrupts()
        self.rfm22.set_op_mode('tx')

        r = self.irq.read()
        while (int(r) == 1):
            r = self.irq.read()
        print "packet sent"
        
        self.rx_ant.write(0)
        self.tx_ant.write(0)


    def run(self):
        pass
        


    def fsm(self):
        """
        Primary control loop.

        This function is the finite state machine that controls the
        operation of the system.
        """

        self._init_io()
        self._init_rf()

        state = "listen"
        f = 434e6

        while True:
            if state == "listen":
                self._listen(f)
                state = "transmit"

            elif state == "transmit":
                self._transmit(f)
                state = "receive"

            elif state == "receive":
                self._receive(f)
                state = "listen"

            else:
                print "+++ Melon melon melon +++"
                state = "listen"
            
        




    def shutdown(self):
        self._kill_io()
Example #12
0
class RF(object):
    def __init__(self, file_num):

        self.file_num = file_num
        interrupt = 157
        tx_port = 138
        rx_port = 139

        spi.setup("/dev/spidev4.0")

        # setup the TR switch
        self.tx_ant = GeneralPurposeIO(tx_port, "out")
        self.tx_ant.write(0)

        self.rx_ant = GeneralPurposeIO(rx_port, "out")
        self.rx_ant.write(0)

        # setup irq line
        self.irq = GeneralPurposeIO(interrupt, "in")

        self.packet = [
            0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A,
            0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x78
        ]

        self.rssi_data = []
        self.packet_count = 0

    def setup_rf(self, fc, hbsel, fb):
        spi.write(0x07, 0x80)  # reset all the registers
        spi.write(0x05, 0x00)  # Disable interrupts in IntStatReg1
        spi.write(0x06, 0x00)  # Disable interrupts in IntStatReg2

        spi.write(0x07, 0x01)  # Set READY mode
        spi.write(0x09, 0x7F)  # Cap = 12.5pF
        spi.write(0x0A, 0x05)  # Clk output is 2MHz
        spi.write(0x0B, 0xF4)  # GPIO0 is for RX data output
        spi.write(0x0C, 0xEF)  # GPIO1 is TX/RX data CLK output
        spi.write(0x0D, 0x00)  # GPIO2 for MCLK output
        spi.write(0x0E, 0x00)  # GPIO port use default value
        spi.write(0x0F, 0x70)  # NO ADC used
        spi.write(0x10, 0x00)  # no ADC used
        spi.write(0x12, 0x00)  # No temp sensor used
        spi.write(0x13, 0x00)  # no temp sensor used
        spi.write(
            0x70,
            0x0C)  # No manchester code, no data whiting, data rate < 30Kbps
        spi.write(0x1C, 0x8A)  # IF filter bandwidth
        spi.write(0x1D, 0x40)  # AFC Loop
        spi.write(0x20, 0x60)  # clock recovery
        spi.write(0x21, 0x01)  # clock recovery
        spi.write(0x22, 0x55)  # clock recovery
        spi.write(0x23, 0x55)  # clock recovery
        spi.write(0x24, 0x02)  # clock recovery timing
        spi.write(0x25, 0xAD)  # clock recovery timing
        spi.write(0x2C, 0x40)
        spi.write(0x2D, 0x0A)
        spi.write(0x2E, 0x50)
        spi.write(0x6E, 0x20)  # TX data rate 1
        spi.write(0x6F, 0x00)  # TX data rate 0
        spi.write(0x30, 0x8C)  # Data access control
        spi.write(0x32, 0xFF)  # Header control
        spi.write(0x33, 0x42)  # Header 3, 2, 1, 0 used for head length,
        # fixed packet length, synchronize word length 3, 2,
        spi.write(0x34, 64)  # 64 nibble = 32 byte preamble
        spi.write(0x35, 0x20)  # 0x35 need to detect 20bit preamble
        spi.write(0x36, 0x2D)  # synchronize word
        spi.write(0x37, 0xD4)
        spi.write(0x38, 0x00)
        spi.write(0x39, 0x00)
        spi.write(0x3A, 0xff)  # set tx header 3
        spi.write(0x3B, 0xff)  # set tx header 2
        spi.write(0x3C, 0xff)  # set tx header 1
        spi.write(0x3D, 0xff)  # set tx header 0
        spi.write(0x3E, 17)  # set packet length to 17 bytes
        spi.write(0x3F, 0xff)  # set rx header
        spi.write(0x40, 0xff)
        spi.write(0x41, 0xff)
        spi.write(0x42, 0xff)
        spi.write(0x43, 0xFF)  # check all bits
        spi.write(0x44, 0xFF)  # Check all bits
        spi.write(0x45, 0xFF)  # check all bits
        spi.write(0x46, 0xFF)  # Check all bits
        spi.write(0x56, 0x01)
        # spi.write(0x6D, 0x04) 		# Tx power to max
        spi.write(0x6D, 0x07)  # Tx power to max
        spi.write(0x79, 0x00)  # no frequency hopping
        spi.write(0x7A, 0x00)  # no frequency hopping
        spi.write(
            0x71, 0x22
        )  # GFSK, fd[8]=0, no invert for TX/RX data, FIFO mode, txclk-->gpio
        spi.write(0x72, 0xc8)  # Frequency deviation setting to 45K=72*625
        spi.write(0x73, 0x00)  # No frequency offset
        spi.write(0x74, 0x00)  # No frequency offset

        val = 0x40 | hbsel << 5 | fb
        spi.write(0x75, val)  # frequency set to 434MHz
        spi.write(0x76, fc >> 8)  # frequency set to 434MHz
        spi.write(0x77, fc & 0xff)  # frequency set to 434Mhz

        spi.write(0x5A, 0x7F)
        spi.write(0x59, 0x60)
        spi.write(0x58, 0x80)
        spi.write(0x6A, 0x0B)
        spi.write(0x68, 0x04)
        spi.write(0x1F, 0x03)

        # spi.write(0x07, 0x80)           # reset all the registers
        # spi.write(0x05, 0x00)           # Disable interrupts in IntStatReg1
        # spi.write(0x06, 0x00)           # Disable interrupts in IntStatReg2

        # spi.write(0x07, 0x01) 		# Set READY mode
        # spi.write(0x09, 0x7F) 		# Cap = 12.5pF
        # spi.write(0x0A, 0x05) 		# Clk output is 2MHz
        # spi.write(0x0B, 0xF4) 		# GPIO0 is for RX data output
        # spi.write(0x0C, 0xEF) 		# GPIO1 is TX/RX data CLK output
        # spi.write(0x0D, 0x00) 		# GPIO2 for MCLK output
        # spi.write(0x0E, 0x00) 		# GPIO port use default value
        # spi.write(0x0F, 0x70) 		# NO ADC used
        # spi.write(0x10, 0x00) 		# no ADC used
        # spi.write(0x12, 0x00) 		# No temp sensor used
        # spi.write(0x13, 0x00) 		# no temp sensor used
        # spi.write(0x70, 0x20) 		# No manchester code, no data whiting, data rate < 30Kbps
        # spi.write(0x1C, 0x1D) 		# IF filter bandwidth
        # spi.write(0x1D, 0x40) 		# AFC Loop
        # spi.write(0x20, 0xA1) 		# clock recovery
        # spi.write(0x21, 0x20) 		# clock recovery
        # spi.write(0x22, 0x4E) 		# clock recovery
        # spi.write(0x23, 0xA5) 		# clock recovery
        # spi.write(0x24, 0x00) 		# clock recovery timing
        # spi.write(0x25, 0x0A) 		# clock recovery timing
        # spi.write(0x2C, 0x00)
        # spi.write(0x2D, 0x00)
        # spi.write(0x2E, 0x00)
        # spi.write(0x6E, 0x27) 		# TX data rate 1
        # spi.write(0x6F, 0x52) 		# TX data rate 0
        # spi.write(0x30, 0x8C) 		# Data access control
        # spi.write(0x32, 0xFF) 		# Header control
        # spi.write(0x33, 0x42) 		# Header 3, 2, 1, 0 used for head length,
        #                                 # fixed packet length, synchronize word length 3, 2,
        # spi.write(0x34, 64) 		# 64 nibble = 32 byte preamble
        # spi.write(0x35, 0x20) 		# 0x35 need to detect 20bit preamble
        # spi.write(0x36, 0x2D) 		# synchronize word
        # spi.write(0x37, 0xD4)
        # spi.write(0x38, 0x00)
        # spi.write(0x39, 0x00)
        # spi.write(0x3A, 0xff) 		# set tx header 3
        # spi.write(0x3B, 0xff) 		# set tx header 2
        # spi.write(0x3C, 0xff) 		# set tx header 1
        # spi.write(0x3D, 0xff) 		# set tx header 0
        # spi.write(0x3E, 17) 		# set packet length to 17 bytes
        # spi.write(0x3F, 0xff) 		# set rx header
        # spi.write(0x40, 0xff)
        # spi.write(0x41, 0xff)
        # spi.write(0x42, 0xff)
        # spi.write(0x43, 0xFF) 		# check all bits
        # spi.write(0x44, 0xFF) 		# Check all bits
        # spi.write(0x45, 0xFF) 		# check all bits
        # spi.write(0x46, 0xFF) 		# Check all bits
        # spi.write(0x56, 0x01)
        # spi.write(0x6D, 0x07) 		# Tx power to max
        # spi.write(0x79, 0x00) 		# no frequency hopping
        # spi.write(0x7A, 0x00) 		# no frequency hopping
        # spi.write(0x71, 0x22) 		# GFSK, fd[8]=0, no invert for TX/RX data, FIFO mode, txclk-->gpio
        # spi.write(0x72, 0x48) 		# Frequency deviation setting to 45K=72*625
        # spi.write(0x73, 0x00) 		# No frequency offset
        # spi.write(0x74, 0x00) 		# No frequency offset

        # val = 0x40 | hbsel << 5 | fb
        # spi.write(0x75, val) 		# frequency set to 434MHz
        # spi.write(0x76, fc >> 8) 		# frequency set to 434MHz
        # spi.write(0x77, fc & 0xff) 		# frequency set to 434Mhz

        # # spi.write(0x75, 0x53) 		# frequency set to 434MHz
        # # spi.write(0x76, 0x64) 		# frequency set to 434MHz
        # # spi.write(0x77, 0x00) 		# frequency set to 434Mhz
        # spi.write(0x5A, 0x7F)
        # spi.write(0x59, 0x40)
        # spi.write(0x58, 0x80)
        # spi.write(0x6A, 0x0B)
        # spi.write(0x68, 0x04)
        # spi.write(0x1F, 0x03)

    def clear_tx_fifo(self):
        spi.write(0x08, 0x01)
        spi.write(0x08, 0x00)

    def clear_rx_fifo(self):
        spi.write(0x08, 0x02)
        spi.write(0x08, 0x00)

    def clear_fifo(self):
        spi.write(0x08, 0x03)
        spi.write(0x08, 0x00)

    def clear_interrupt(self):
        i = spi.read(0x03)
        i = spi.read(0x04)

    def set_rx_fifo_almost_full_threshold(self, threshold):
        spi.write(0x7E, threshold)

    def set_tx_fifo_almost_full_threshold(self, threshold):
        pass

    def read_rx_fifo(self):
        return spi.read(0x7F)

    def set_rfm22_state(self, rfm22_state):
        if rfm22_state == 'tx':
            spi.write(0x07, 0x09)

        elif rfm22_state == 'rx':
            spi.write(0x07, 0x05)

        else:
            pass

    def set_rfm22_mode(self, mode):
        if mode == 'ready':
            spi.write(0x07, 0x01)

        elif mode == 'tune':
            spi.write(0x07, 0x03)

        else:
            pass

    def enable_interrupt(self, signal):
        reg_1 = spi.read(0x05)
        reg_2 = spi.read(0x06)
        if signal == 'valid_packet_received':
            spi.write(0x05, reg_1 | 0x02)
        else:
            print "error in enable_interrupt"

    def module_power_state(self):
        status = spi.read(0x02)
        power_state = status & 0x03
        if power_state == 0x00:
            return 'idle'
        elif power_state == 0x01:
            return 'rx'
        elif power_state == 0x02:
            return 'tx'
        else:
            print "error in module_power_state"

    def receive(self):
        self.set_rfm22_mode('ready')

        # is there any particular order these should be in?
        self.set_rx_fifo_almost_full_threshold(17)
        self.tx_ant.write(0)
        self.rx_ant.write(1)
        self.clear_interrupt()
        self.clear_fifo()
        self.set_rfm22_state('rx')
        self.enable_interrupt('valid_packet_received')
        print "RSSI Threshold: ", '{0:d}'.format(spi.read(0x27))
        print "RSSI Indicator: ", '{0:d}'.format(spi.read(0x26))

        print "receiving packet..."
        while self.module_power_state() == 'rx':
            result = self.irq.read()
            rssi = '{0:d}'.format(spi.read(0x26))
            self.rssi_data.append([time.time(), rssi])
            # print "RSSI Indicator: ", rssi
            # print "interrupt: ", int(result)
            if (int(result) == 0):
                rx_buffer = []

                for i in range(17):
                    rx_buffer.append(self.read_rx_fifo())

                if (rx_buffer == self.packet):
                    print "Packet Received"
                    self.packet_count += 1

    def _fsm(self, fsm_state):

        while True:

            if fsm_state == 'idle':
                pass

            elif fsm_state == 'tx':
                pass

            elif fsm_state == 'rx':
                fc, hbsel, fb = freq_utils.carrier_freq(434e6)
                self.setup_rf(fc, hbsel, fb)
                self.receive()
                if self.packet_count == 50:
                    break
                else:
                    state = 'rx'
            else:
                pass

    def run(self):
        self._fsm('rx')

    def shutdown(self):
        self.close_gpio()

        f = open("rssi_data_" + self.file_num + '.txt', 'w')
        for i in self.rssi_data:
            f.write(str(i) + "\n")
        f.close()

    def close_gpio(self):
        self.tx_ant.close()
        self.rx_ant.close()
        self.irq.close()