src/adafruit_blinka/microcontroller/rp2040/i2c.py

   1 # SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries
   2 #
   3 # SPDX-License-Identifier: MIT
   4 """I2C Class for RP2040"""
   5 from machine import I2C as _I2C
   6 from machine import Pin
   7 from microcontroller.pin import i2cPorts
   8
   9
  10 class I2C:
  11     """Custom I2C Class for RP2040"""
  12
  13     def __init__(self, scl, sda, *, frequency=100000):
  14         for portId, portScl, portSda in i2cPorts:
  15             try:
  16                 if scl == portScl and sda == portSda:
  17                     self._i2c = _I2C(
  18                         portId, sda=Pin(sda.id), scl=Pin(scl.id), freq=frequency
  19                     )
  20                     break
  21             except RuntimeError:
  22                 pass
  23         else:
  24             raise ValueError(
  25                 "No Hardware I2C on (scl,sda)={}\nValid I2C ports: {}".format(
  26                     (scl, sda), i2cPorts
  27                 )
  28             )
  29
  30     def scan(self):
  31         """Perform an I2C Device Scan"""
  32         return self._i2c.scan()
  33
  34     def writeto(self, address, buffer, *, stop=True):
  35         "Write data to the address from the buffer"
  36         return self._i2c.writeto(address, buffer, stop)
  37
  38     def readfrom_into(self, address, buffer, *, stop=True):
  39         """Read data from an address and into the buffer"""
  40         return self._i2c.readfrom_into(address, buffer, stop)
  41
  42     def writeto_then_readfrom(
  43         self,
  44         address,
  45         buffer_out,
  46         buffer_in,
  47         *,
  48         out_start=0,
  49         out_end=None,
  50         in_start=0,
  51         in_end=None,
  52         stop=False,
  53     ):
  54         """Write data from buffer_out to an address and then
  55         read data from an address and into buffer_in
  56         """
  57         if out_end:
  58             self.writeto(address, buffer_out[out_start:out_end], stop=stop)
  59         else:
  60             self.writeto(address, buffer_out[out_start:], stop=stop)
  61
  62         if not in_end:
  63             in_end = len(buffer_in)
  64         read_buffer = memoryview(buffer_in)[in_start:in_end]
  65         self.readfrom_into(address, read_buffer, stop=stop)