src/adafruit_blinka/microcontroller/ft232h/i2c.py

   1 from adafruit_blinka.microcontroller.ft232h.pin import Pin
   2
   3 class I2C:
   4
   5     def __init__(self):
   6         # change GPIO controller to I2C
   7         from pyftdi.i2c import I2cController
   8         self._i2c = I2cController()
   9         self._i2c.configure('ftdi:///1')
  10         Pin.ft232h_gpio = self._i2c.get_gpio()
  11
  12     def writeto(self, address, buffer, *, start=0, end=None, stop=True):
  13         end = end if end else len(buffer)
  14         port = self._i2c.get_port(address)
  15         port.write(buffer[start:end], relax=stop)
  16
  17     def readfrom_into(self, address, buffer, *, start=0, end=None, stop=True):
  18         end = end if end else len(buffer)
  19         port = self._i2c.get_port(address)
  20         result = port.read(len(buffer[start:end]), relax=stop)
  21         for i, b in enumerate(result):
  22             buffer[start+i] = b
  23
  24     def writeto_then_readfrom(self, address, buffer_out, buffer_in, *,
  25                               out_start=0, out_end=None,
  26                               in_start=0, in_end=None, stop=False):
  27         out_end = out_end if out_end else len(buffer_out)
  28         in_end = in_end if in_end else len(buffer_in)
  29         port = self._i2c.get_port(address)
  30         result = port.exchange(buffer_out[out_start:out_end],
  31                                in_end-in_start,
  32                                relax=True).tobytes()
  33         for i, b in enumerate(result):
  34             buffer_in[in_start+i] = b