src/adafruit_blinka/microcontroller/rp2040/i2c.py

   1 """I2C Class for RP2040"""
   2 from machine import I2C as _I2C
   3 from machine import Pin
   4 from microcontroller.pin import i2cPorts
   5
   6
   7 class I2C:
   8     """Custom I2C Class for RP2040"""
   9
  10     def __init__(self, scl, sda, *, frequency=100000):
  11         for portId, portScl, portSda in i2cPorts:
  12             try:
  13                 if scl == portScl and sda == portSda:
  14                     self._i2c = _I2C(
  15                         portId, sda=Pin(sda.id), scl=Pin(scl.id), freq=frequency
  16                     )
  17                     break
  18             except RuntimeError:
  19                 pass
  20         else:
  21             raise ValueError(
  22                 "No Hardware I2C on (scl,sda)={}\nValid I2C ports: {}".format(
  23                     (scl, sda), i2cPorts
  24                 )
  25             )
  26
  27     def scan(self):
  28         """Perform an I2C Device Scan"""
  29         return self._i2c.scan()
  30
  31     def writeto(self, address, buffer, *, stop=True):
  32         "Write data to the address from the buffer"
  33         return self._i2c.writeto(address, buffer, stop)
  34
  35     def readfrom_into(self, address, buffer, *, stop=True):
  36         """Read data from an address and into the buffer"""
  37         return self._i2c.readfrom_into(address, buffer, stop)
  38
  39     def writeto_then_readfrom(
  40         self,
  41         address,
  42         buffer_out,
  43         buffer_in,
  44         *,
  45         out_start=0,
  46         out_end=None,
  47         in_start=0,
  48         in_end=None,
  49         stop=False
  50     ):
  51         """Write data from buffer_out to an address and then
  52         read data from an address and into buffer_in
  53         """
  54         if out_end:
  55             self.writeto(address, buffer_out[out_start:out_end], stop=stop)
  56         else:
  57             self.writeto(address, buffer_out[out_start:], stop=stop)
  58
  59         if not in_end:
  60             in_end = len(buffer_in)
  61         read_buffer = memoryview(buffer_in)[in_start:in_end]
  62         self.readfrom_into(address, read_buffer, stop=stop)