def __init__(self):
logger.debug('Initializing __VecHandles')
self.vec = MPSSE()
logger.debug('opening vec')
self.vec.Open(0x0403, 0x6011, I2C, ONE_HUNDRED_KHZ, MSB, IFACE_A)
# Port B I2C for debug leds (don't need the io expander for the DPS sensors)
self.gpio = MPSSE()
logger.debug('opening gpio')
self.gpio.Open(0x0403, 0x6011, I2C, ONE_HUNDRED_KHZ, MSB, IFACE_B)
# Set RESET line on PCA9546A to high to activate switch
logger.debug('GPIOL0 high')
self.vec.PinHigh(GPIOL0)
# Make sure reset line is held high on MCP23017 in order to use it
logger.debug('GPIOL2 high')
self.vec.PinHigh(GPIOL2)
time.sleep(0.005)
# Since the control line has a pull up resistor we want to only set it low to
# active and use the pull up to make it inactive. To do this we need to use
# the IO direction register in the actual setting of low and high (pull line
# low or leave in high impedance which uses the pull up resistor)
# In order to use the IO direction register we must set associated latch
# register to 1 so when the IO direction is set to an output it will cause the
# IO pin connected to the control line to go high
# Set Port A and B latches on CE (card edge).
self.gpio.Start()
logger.debug('writing: {}'.format(
hexlify(WRITE_23017 + OLATA_23017 + LATCHA_CE)))
self.gpio.Write(WRITE_23017 + OLATA_23017 + LATCHA_CE)
self.gpio.Stop()
# Set Port B latches.
self.gpio.Start()
logger.debug('writing: {}'.format(
hexlify(WRITE_23017 + OLATB_23017 + LATCHB_CE)))
self.gpio.Write(WRITE_23017 + OLATB_23017 + LATCHB_CE)
self.gpio.Stop()
# Set Port A latches on expansion.
# Need to set the PCA9546A to channel 3 first.
self.vec.Start()
logger.debug('writing: {}'.format(hexlify(CHANNEL3)))
self.vec.Write(CHANNEL3)
self.vec.Stop()
self.vec.Start()
logger.debug('writing: {}'.format(
hexlify(WRITE_23017 + OLATA_23017 + LATCH_OCTO)))
self.vec.Write(WRITE_23017 + OLATA_23017 + LATCH_OCTO)
self.vec.Stop()
logger.debug('vec and gpio initialized')
def _open_i2c_lock(interface):
"""
Open and initialize the port in the FT4232H for i2c lock operations.
:param interface: The port index of the FT4232H. IFACE_A or IFACE_B.
:return: Handle to i2c interface for the port.
"""
vec = MPSSE()
vec.Open(
0x0403, # VID
0x6011, # PID
I2C, # mode
ONE_HUNDRED_KHZ, # Clock frequency
MSB, # endianess. I2C is always MSB.
interface) # interface
return vec
def get_default_mpsse(speed_mhz):
"""Open the first MPSSE device found and return it. Throws an exception if
no MPSSE device is found."""
from mpsse import MPSSE
mpsse = MPSSE(SPI0, speed_mhz, MSB)
if mpsse is None:
RuntimeError('Could not find a connected MPSSE device!')
return mpsse
def _open_vec_i2c():
"""Open the i2c port on the VEC USB for i2c operations."""
# Port A I2C for PCA9546A
vec = MPSSE()
vec.Open(0x0403, 0x6011, I2C, ONE_HUNDRED_KHZ, MSB, IFACE_A)
# Port B I2C for debug leds (don't need the io expander for the DPS sensors)
gpio = MPSSE()
gpio.Open(0x0403, 0x6011, I2C, ONE_HUNDRED_KHZ, MSB, IFACE_B)
# Set RESET line on PCA9546A to high to activate switch
vec.PinHigh(GPIOL0)
time.sleep(0.001)
# Read channel of PCA9546A
vec.Start()
vec.Write(PCA9546_READ_ADDRESS)
return vec, gpio
def configure_differential_pressure(channel):
""" Configure the differential pressure sensor for 9 bit resolution.
Default is 12. This needs to be done once per power up. For our case we call this
on synse container startup.
Args:
channel: The channel to configure.
"""
logger.debug(
'Configuring Differential Pressure sensor on channel {}'.format(
channel))
# Port A I2C for PCA9546A
vec = MPSSE()
vec.Open(0x0403, 0x6011, I2C, ONE_HUNDRED_KHZ, MSB, IFACE_A)
# Set RESET line on PCA9546A to high to activate switch
vec.PinHigh(GPIOL0)
time.sleep(0.001)
channel_str = PCA9546_WRITE_ADDRESS + chr(channel)
logger.debug('PCA9546_WRITE_ADDRESS is: {}'.format(
hexlify(PCA9546_WRITE_ADDRESS)))
logger.debug('channel_str is: {}'.format(hexlify(channel_str)))
vec.Start()
vec.Write(channel_str)
vec.Stop()
logger.debug('PCA9546_READ_ADDRESS is: {}'.format(
hexlify(PCA9546_READ_ADDRESS)))
# verify channel was set
vec.Start()
vec.Write(PCA9546_READ_ADDRESS)
vec.SendNacks()
reg = vec.Read(1)
vec.Stop()
vec.SendAcks()
logger.debug('PCA9546A Control Register: 0x{:02x}'.format(ord(reg)))
# Configure Sensor
# In the application note for changing measurement resolution three things must be met.
# 1. Read the advanced user register.
# 2. Define the new register entry according to the desired resolution.
# 3. Write the new value to the advanced register.
vec.Start()
vec.Write('\x80\xE5')
vec.Start()
vec.Write('\x81')
# At this point the sensor needs to hold the master but the FT4232 doesn't do clock stretching.
time.sleep(0.001) # This stays at 1 ms regardless of sensor resolution.
# Read the three bytes out of the DPS sensor (two data bytes and crc)
sensor_data = vec.Read(3)
logger.debug('Raw sensor_data: {}'.format(hexlify(sensor_data)))
vec.Stop()
# write new value for 9 bit resolution (0b000 for bits 9 - 11)
if _crc8(sensor_data):
# Hardcoded 9 bit sensor resolution.
sensor_int = 0x7182
msb = sensor_int >> 8
lsb = sensor_int & 0xFF
register_str = '\x80\xE4' + chr(msb) + chr(lsb)
vec.Start()
vec.Write(register_str)
vec.Stop()
logger.debug(
'Configured DP Sensor on channel {} for 9 bit resolution.'.format(
channel))
rc = 0
else:
logger.error('CRC failed configuring DP Sensor.')
rc = 1
vec.Stop()
vec.Close()
return rc
def _open_led_i2c():
"""Open the i2c port on the VEC USB for led controller operations."""
# Construct string to set channel number to 3
channel_str = PCA9546_WRITE_ADDRESS + '\x08'
# Port A I2C for PCA9546A
vec = MPSSE()
vec.Open(0x0403, 0x6011, I2C, ONE_HUNDRED_KHZ, MSB, IFACE_A)
# Port B I2C for debug leds (don't need the io expander for the LED Port)
gpio = MPSSE()
gpio.Open(0x0403, 0x6011, I2C, ONE_HUNDRED_KHZ, MSB, IFACE_B)
# Set RESET line on PCA9546A to high to activate switch
vec.PinHigh(GPIOL0)
# Set channel on PCA9546A to 3 for PCA9632 (LED Port) Keep in mind this
# also is connected to the MAX11608
vec.Start()
vec.Write(channel_str)
vec.Stop()
# verify channel was set.
vec.Start()
vec.Write(PCA9546_READ_ADDRESS)
vec.SendNacks()
reg = vec.Read(1)
vec.Stop()
reg = ord(reg)
if reg != 0x08:
raise ValueError('Failed to set PCA9546A Control Register to 0x08. Is 0x{:02x}'.format(reg))
vec.SendAcks()
vec.Start()
# Configure PCA9632 for our setup (IE totem pole with inverted driver output, etc)
# Writes to Mode 1 and Mode 2 Registers
vec.Start()
vec.Write('\xC4\x80\x00\x35')
vec.Stop()
return vec, gpio