kopia lustrzana https://github.com/micropython/micropython-lib
eeprom: Add I2C EEPROM driver.
For AT24Cxx EEPROMs. Signed-off-by: Jonas Scharpf <jonas@brainelectronics.de>pull/640/head
Jonas Scharpf
rodzic
ea21cb3fdc
commit
450818c46e
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@ -0,0 +1,285 @@
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#!/usr/bin/env python3
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# -*- coding: UTF-8 -*-
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"""
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I2C EEPROM driver for AT24Cxx
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Requires an I2C bus, for further details check
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https://github.com/brainelectronics/micropython-eeprom
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Example usage:
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from eeprom import EEPROM
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from machine import I2C, Pin
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# define custom I2C interface, default is 'I2C(0)'
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# check the docs of your device for further details and pin infos
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i2c = I2C(0, scl=Pin(13), sda=Pin(12), freq=800000)
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eeprom = EEPROM(addr=0x50, at24x=32, i2c=i2c) # AT24C32 on 0x50
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# get LCD infos/properties
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print("EEPROM is on I2C address 0x{0:02x}".format(eeprom.addr))
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print("EEPROM has {} pages of {} bytes".format(eeprom.pages, eeprom.bpp))
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print("EEPROM size is {} bytes ".format(eeprom.capacity))
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# read 1 byte from address 4
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eeprom.read(4)
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# read 10 byte from address 7
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eeprom.read(7, 10)
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EEPROM data sheet: https://ww1.microchip.com/downloads/en/DeviceDoc/doc0336.pdf
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MIT License
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Copyright (c) 2018 Mike Causer
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Extended 2023 by brainelectronics
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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"""
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# system packages
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from machine import I2C
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from time import sleep_ms
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class _Subscriptable:
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def __getitem__(self, item):
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return None
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_subscriptable = _Subscriptable()
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List = _subscriptable
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Optional = _subscriptable
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Union = _subscriptable
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class EEPROM(object):
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"""Driver for AT24Cxx I2C EEPROM"""
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def __init__(
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self,
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addr: int = 0x50,
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pages: int = 128,
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bpp: int = 32,
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i2c: Optional[I2C] = None,
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at24x: int = 0,
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) -> None:
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"""
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Constructs a new instance
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:param addr: The I2C bus address of the EEPROM
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:type addr: int
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:param pages: The number of pages of the EEPROM
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:type pages: int
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:param bpp: The bytes per page
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:type bpp: int
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:param i2c: I2C object
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:type i2c: I2C
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:param at24x: The specific AT24Cxx, either 32, 64, 128, 256, 512
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:type at24x: int
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"""
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self._addr = addr
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standard_eeproms = {
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32: [128, 32], # 4KiB 32Kbits, 128 pages, 32 bytes/page
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64: [256, 32], # 8KiB 64Kbits, 256 pages, 32 bytes/page
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128: [256, 64], # 16KiB 128Kbits, 256 pages, 64 bytes/page
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256: [512, 64], # 32KiB 256Kbits, 512 pages, 64 bytes/page
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512: [512, 128], # 64KiB 512Kbits, 512 pages, 128 bytes/page
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}
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if at24x in standard_eeproms:
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self._pages, self._bpp = standard_eeproms[at24x]
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else:
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self._pages = pages
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self._bpp = bpp
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if i2c is None:
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# default assignment, check the docs
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self._i2c = I2C(0)
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else:
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self._i2c = i2c
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@property
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def addr(self) -> int:
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"""
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Get the EEPROM I2C bus address
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:returns: EEPROM I2C bus address
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:rtype: int
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"""
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return self._addr
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@property
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def capacity(self) -> int:
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"""
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Get the storage capacity of the EEPROM
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:returns: EEPROM capacity of the EEPROM in bytes
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:rtype: int
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"""
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return self._pages * self._bpp
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@property
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def pages(self) -> int:
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"""
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Get the number of EEPROM pages
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:returns: Number of pages of the EEPROM
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:rtype: int
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"""
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return self._pages
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@property
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def bpp(self) -> int:
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"""
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Get the bytes per page of the EEPROM
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:returns: Bytes per pages of the EEPROM
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:rtype: int
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"""
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return self._bpp
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def length(self) -> int:
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"""
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Get the EEPROM length
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:returns: Number of cells in the EEPROM
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:rtype: int
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"""
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return self.capacity
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def read(self, addr: int, nbytes: int = 1) -> bytes:
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"""
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Read bytes from the EEPROM
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:param addr: The start address
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:type addr: int
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:param nbytes: The number of bytes to read
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:type nbytes: int
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:returns: Data of EEPROM
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:rtype: bytes
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"""
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if addr > self.capacity or addr < 0:
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raise ValueError(
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"Read address {} outside of device address range {}".format(addr, self.capacity)
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)
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if addr + nbytes > self.capacity:
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raise ValueError(
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"Last read address {} outside of device address range {}".format(
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addr + nbytes, self.capacity
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)
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)
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return self._i2c.readfrom_mem(self._addr, addr, nbytes, addrsize=16)
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def write(self, addr: int, buf: Union[bytes, List[int], str]) -> None:
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"""
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Write data to the EEPROM
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:param addr: The start address
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:type addr: int
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:param buf: The buffer to write to the EEPROM
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:type buf: Union[bytes, List[int], str]
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"""
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offset = addr % self._bpp
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partial = 0
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if addr > self.capacity or addr < 0:
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raise ValueError(
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"Write address {} outside of device address range {}".format(addr, self.capacity)
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)
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if addr + len(buf) > self.capacity:
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raise ValueError(
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"Last data at {} does not fit into device address range {}".format(
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addr + len(buf), self.capacity
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)
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)
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# partial page write
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if offset > 0:
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partial = self._bpp - offset
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self._i2c.writeto_mem(self._addr, addr, buf[0:partial], addrsize=16)
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sleep_ms(5)
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addr += partial
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# full page write
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for i in range(partial, len(buf), self._bpp):
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self._i2c.writeto_mem(
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self._addr, addr + i - partial, buf[i : i + self._bpp], addrsize=16
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)
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sleep_ms(5)
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def update(self, addr: int, buf: Union[bytes, List[int], str]) -> None:
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"""
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Update data in EEPROM
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:param addr: The start address
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:type addr: int
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:param buf: The buffer to write to the EEPROM
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:type buf: Union[bytes, List[int], str]
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"""
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for idx, ele in enumerate(buf):
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this_addr = addr + idx
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if isinstance(ele, int):
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this_val = ele.to_bytes(1, "big")
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else:
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this_val = str(ele).encode()
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current_value = self.read(addr=this_addr) # returns bytes
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if current_value != this_val:
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self.write(addr=this_addr, buf=this_val)
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# print("{}: {} -> {}".
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# format(this_addr, current_value, this_val))
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# else:
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# print("No need to update value at {}".format(this_addr))
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def wipe(self) -> None:
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"""Wipe the complete EEPROM"""
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page_buff = b"\xff" * self.bpp
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for i in range(self.pages):
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self.write(i * self.bpp, page_buff)
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def print_pages(self, addr: int, nbytes: int) -> None:
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"""
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Print pages content with boundaries.
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:param addr: The start address
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:type addr: int
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:param nbytes: The number of bytes to read
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:type nbytes: int
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"""
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unknown_data_first_page = addr % self.bpp
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unknown_data_last_page = self.bpp - (addr + nbytes) % self.bpp
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if unknown_data_last_page % self.bpp == 0:
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unknown_data_last_page = 0
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data = self.read(addr=addr, nbytes=nbytes)
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extended_data = b"?" * unknown_data_first_page + data + b"?" * unknown_data_last_page
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sliced_data = [
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extended_data[i : i + self.bpp] for i in range(0, len(extended_data), self.bpp)
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]
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print("Page {:->4}: 0 {} {}".format("x", "-" * (self.bpp - len(str(self.bpp))), self.bpp))
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for idx, a_slice in enumerate(sliced_data):
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print("Page {:->4}: {}".format(idx, a_slice))
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@ -0,0 +1,3 @@
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metadata(description="EEPROM device driver.", version="0.1.0")
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module("eeprom.py", opt=3)
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