def begin(self, major, minor, ce_pin, irq_pin):
# Initialize SPI bus
self.spidev = spidev.SpiDev()
self.spidev.open(major,minor)
self.ce_pin = ce_pin
self.irq_pin = irq_pin
GPIO.setup(self.ce_pin, GPIO.OUT)
GPIO.setup(self.irq_pin, GPIO.IN, pull_up_down=GPIO.PUD_UP)
time.sleep(5/1000000.0)
# Set 1500uS (minimum for 32B payload in ESB@250KBPS) timeouts, to make testing a little easier
# WARNING: If this is ever lowered, either 250KBS mode with AA is broken or maximum packet
# sizes must never be used. See documentation for a more complete explanation.
self.write_register(NRF24.SETUP_RETR,(int('0100',2) << NRF24.ARD) | (int('1111',2) << NRF24.ARC))
# Restore our default PA level
self.setPALevel( NRF24.PA_MAX )
# Determine if this is a p or non-p RF24 module and then
# reset our data rate back to default value. This works
# because a non-P variant won't allow the data rate to
# be set to 250Kbps.
if self.setDataRate( NRF24.BR_250KBPS ):
self.p_variant = True
# Then set the data rate to the slowest (and most reliable) speed supported by all
# hardware.
self.setDataRate( NRF24.BR_1MBPS )
# Initialize CRC and request 2-byte (16bit) CRC
self.setCRCLength( NRF24.CRC_16 )
# Disable dynamic payloads, to match dynamic_payloads_enabled setting
self.write_register( NRF24.DYNPD,0)
# Reset current status
# Notice reset and flush is the last thing we do
self.write_register( NRF24.STATUS, _BV(NRF24.RX_DR) | _BV(NRF24.TX_DS) | _BV(NRF24.MAX_RT) )
# Set up default configuration. Callers can always change it later.
# This channel should be universally safe and not bleed over into adjacent
# spectrum.
self.setChannel(self.channel)
# Flush buffers
self.flush_rx()
self.flush_tx()
def ce(self, level): if level == NRF24.HIGH: GPIO.output(self.ce_pin, GPIO.HIGH) else: GPIO.output(self.ce_pin, GPIO.LOW) return
def irqWait(self):
# A race condition may occur here.
# Should set a timeout
if GPIO.input(self.irq_pin) == 0:
return
def ce(self, level):
if level == NRF24.HIGH:
GPIO.output(self.ce_pin, GPIO.HIGH)
else:
GPIO.output(self.ce_pin, GPIO.LOW)
return
def irqWait(self):
# A race condition may occur here.
# Should set a timeout
if GPIO.input(self.irq_pin) == 0:
return
GPIO.wait_for_edge(self.irq_pin, GPIO.FALLING)
def read_register(self, reg, blen = 1):
buffer = [NRF24.R_REGISTER | ( NRF24.REGISTER_MASK & reg )]
for col in range(blen):
buffer.append(NRF24.NOP)
resp = self.spidev.xfer2(buffer)
if blen == 1:
return resp[1]
return resp[1:blen+1]
def write_register(self, reg, value, length = -1):
buffer = [NRF24.W_REGISTER | ( NRF24.REGISTER_MASK & reg )]
if isinstance(value,(int, long)):