class interface:
def __init__(self, bus_number: int):
self.bus = SMBus(bus_number)
return
# Get a sensor readings from an arduino with a given id.
# This will ultimately call the `get_sensor_[number]()`
# function on the specified arduino. The arduino will
# send the value over I2C and it will be returned from
# this function.
def get_sensor_reading(self, arduino_ID: int, sensor_number: int):
# Request reading from sensor, Data returned as float in 4 Bytes
sensor_data = bytearray(
self.bus.read_block_data(arduino_ID, sensor_number, 4))
# Convert 4 raw bytes into Float value
# Uses BIG ENDIAN, This may be incorrect. If float values are
# incorrect, try '>f' instead
value = struct.unpack('>f', sensor_data[:4])
return value
# Send a text command to the arduino, This will call the `handle_commnd()`
# function on thw arduino. No value is returned from the arduino.
def send_command(self, arduino_ID: int, command_code: int,
extra_data: bytearray):
# Create Data array to send
data_array = bytearray(command_code) + extra_data
# Send command over I2C
self.bus.write_block_data(arduino_ID, I2C_COMMAND_CODE, data_array)
return
class i2c_device: def __init__(self, addr, port=I2CBUS): self.addr = addr self.bus = SMBus(port) # Write a single command def write_cmd(self, cmd): self.bus.write_byte(self.addr, cmd) sleep(0.0001) # Write a command and argument def write_cmd_arg(self, cmd, data): self.bus.write_byte_data(self.addr, cmd, data) sleep(0.0001) # Write a block of data def write_block_data(self, cmd, data): self.bus.write_block_data(self.addr, cmd, data) sleep(0.0001) # Read a single byte def read(self): return self.bus.read_byte(self.addr) # Read def read_data(self, cmd): return self.bus.read_byte_data(self.addr, cmd) # Read a block of data def read_block_data(self, cmd): return self.bus.read_block_data(self.addr, cmd)
