''' PiicoDev.py: Unifies I2C drivers for different builds of MicroPython Changelog: - 2022-10-13 P.Johnston Add helptext to run i2csetup script on Raspberry Pi - 2022-10-14 M.Ruppe Explicitly set default I2C initialisation parameters for machine-class (Raspberry Pi Pico + W) - 2023-01-31 L.Howell Add minimal support for ESP32 ''' import os _SYSNAME = os.uname().sysname compat_ind = 1 i2c_err_str = 'PiicoDev could not communicate with module at address 0x{:02X}, check wiring' setupi2c_str = ', run "sudo curl -L https://piico.dev/i2csetup | bash". Suppress this warning by setting suppress_warnings=True' if _SYSNAME == 'microbit': from microbit import i2c from utime import sleep_ms elif _SYSNAME == 'Linux': from smbus2 import SMBus, i2c_msg from time import sleep from math import ceil def sleep_ms(t): sleep(t/1000) else: from machine import I2C, Pin from utime import sleep_ms class I2CBase: def writeto_mem(self, addr, memaddr, buf, *, addrsize=8): raise NotImplementedError('writeto_mem') def readfrom_mem(self, addr, memaddr, nbytes, *, addrsize=8): raise NotImplementedError('readfrom_mem') def write8(self, addr, buf, stop=True): raise NotImplementedError('write') def read16(self, addr, nbytes, stop=True): raise NotImplementedError('read') def __init__(self, bus=None, freq=None, sda=None, scl=None): raise NotImplementedError('__init__') class I2CUnifiedMachine(I2CBase): def __init__(self, bus=None, freq=None, sda=None, scl=None): if bus is not None and freq is not None and sda is not None and scl is not None: print('Using supplied freq, sda and scl to create machine I2C') self.i2c = I2C(bus, freq=freq, sda=sda, scl=scl) elif _SYSNAME == 'esp32' and (bus is None and freq is None and sda is None and scl is None): raise Exception('Please input bus, frequency, machine.pin SDA and SCL objects to use ESP32') else: self.i2c = I2C(0, scl=Pin(9), sda=Pin(8), freq=100000) self.writeto_mem = self.i2c.writeto_mem self.readfrom_mem = self.i2c.readfrom_mem def write8(self, addr, reg, data): if reg is None: self.i2c.writeto(addr, data) else: self.i2c.writeto(addr, reg + data) def read16(self, addr, reg): self.i2c.writeto(addr, reg, False) return self.i2c.readfrom(addr, 2) class I2CUnifiedMicroBit(I2CBase): def __init__(self, freq=None): if freq is not None: print('Initialising I2C freq to {}'.format(freq)) microbit.i2c.init(freq=freq) def writeto_mem(self, addr, memaddr, buf, *, addrsize=8): ad = memaddr.to_bytes(addrsize // 8, 'big') # pad address for eg. 16 bit i2c.write(addr, ad + buf) def readfrom_mem(self, addr, memaddr, nbytes, *, addrsize=8): ad = memaddr.to_bytes(addrsize // 8, 'big') # pad address for eg. 16 bit i2c.write(addr, ad, repeat=True) return i2c.read(addr, nbytes) def write8(self, addr, reg, data): if reg is None: i2c.write(addr, data) else: i2c.write(addr, reg + data) def read16(self, addr, reg): i2c.write(addr, reg, repeat=True) return i2c.read(addr, 2) class I2CUnifiedLinux(I2CBase): def __init__(self, bus=None, suppress_warnings=True): if suppress_warnings == False: with open('/boot/config.txt') as config_file: if 'dtparam=i2c_arm=on' in config_file.read(): pass else: print('I2C is not enabled. To enable' + setupi2c_str) config_file.close() with open('/boot/config.txt') as config_file: if 'dtparam=i2c_arm_baudrate=400000' in config_file.read(): pass else: print('Slow baudrate detected. If glitching occurs' + setupi2c_str) config_file.close() if bus is None: bus = 1 self.i2c = SMBus(bus) def readfrom_mem(self, addr, memaddr, nbytes, *, addrsize=8): data = [None] * nbytes # initialise empty list self.smbus_i2c_read(addr, memaddr, data, nbytes, addrsize=addrsize) return data def writeto_mem(self, addr, memaddr, buf, *, addrsize=8): self.smbus_i2c_write(addr, memaddr, buf, len(buf), addrsize=addrsize) def smbus_i2c_write(self, address, reg, data_p, length, addrsize=8): ret_val = 0 data = [] for index in range(length): data.append(data_p[index]) if addrsize == 8: msg_w = i2c_msg.write(address, [reg] + data) elif addrsize == 16: msg_w = i2c_msg.write(address, [reg >> 8, reg & 0xff] + data) else: raise Exception('address must be 8 or 16 bits long only') self.i2c.i2c_rdwr(msg_w) return ret_val def smbus_i2c_read(self, address, reg, data_p, length, addrsize=8): ret_val = 0 if addrsize == 8: msg_w = i2c_msg.write(address, [reg]) # warning this is set up for 16-bit addresses elif addrsize == 16: msg_w = i2c_msg.write(address, [reg >> 8, reg & 0xff]) # warning this is set up for 16-bit addresses else: raise Exception('address must be 8 or 16 bits long only') msg_r = i2c_msg.read(address, length) self.i2c.i2c_rdwr(msg_w, msg_r) if ret_val == 0: for index in range(length): data_p[index] = ord(msg_r.buf[index]) return ret_val def write8(self, addr, reg, data): if reg is None: d = int.from_bytes(data, 'big') self.i2c.write_byte(addr, d) else: r = int.from_bytes(reg, 'big') d = int.from_bytes(data, 'big') self.i2c.write_byte_data(addr, r, d) def read16(self, addr, reg): regInt = int.from_bytes(reg, 'big') return self.i2c.read_word_data(addr, regInt).to_bytes(2, byteorder='little', signed=False) def create_unified_i2c(bus=None, freq=None, sda=None, scl=None, suppress_warnings=True): if _SYSNAME == 'microbit': i2c = I2CUnifiedMicroBit(freq=freq) elif _SYSNAME == 'Linux': i2c = I2CUnifiedLinux(bus=bus, suppress_warnings=suppress_warnings) else: i2c = I2CUnifiedMachine(bus=bus, freq=freq, sda=sda, scl=scl) return i2c