Microchip社のI2C-EEPROMに対応するライブラリを作ってみた。
全ての製品を試したわけではないが基本的にページサイズとメモリサイズが合っていれば動作するはず。容量拡大のために同一仕様のEEPROMを複数搭載した回路にも対応している。
begin/read/writeの３関数しかないので説明しなくても簡単に使えると思う。
【スケッチ】
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#include <Wire.h> #include "eeprom24.h" DECLARE_AT24C32(Wire) eeprom; #define MEM_ADDR 0 void setup(void) { uint8_t conf[32]; eeprom.begin(0); /* device address is 0x50 */ /* read eeprom */ eeprom.read(MEM_ADDR, conf, sizeof(conf)); /* write eeprom */ eeprom.write(MEM_ADDR, conf, sizeof(conf)); } void loop(void) { } |
【ライブラリ】
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/* eeprom24.h - Microchip I2C EEPROM Library for ARDUINO Copyright (c) 2024 Sasapea's Lab. All right reserved. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <https://www.gnu.org/licenses/>. */ #pragma once #include <stdint.h> #include <stdbool.h> #define DECLARE_AT24C01(instance) EEPROM24<typeof(instance), instance, 8, 7> #define DECLARE_AT24C02(instance) EEPROM24<typeof(instance), instance, 8, 8> #define DECLARE_AT24C04(instance) EEPROM24<typeof(instance), instance, 16, 9> #define DECLARE_AT24C08(instance) EEPROM24<typeof(instance), instance, 16, 10> #define DECLARE_AT24C16(instance) EEPROM24<typeof(instance), instance, 16, 11> #define DECLARE_AT24C32(instance) EEPROM24<typeof(instance), instance, 32, 12> #define DECLARE_AT24C64(instance) EEPROM24<typeof(instance), instance, 32, 13> #define DECLARE_AT24C128(instance) EEPROM24<typeof(instance), instance, 64, 14> #define DECLARE_AT24C256(instance) EEPROM24<typeof(instance), instance, 64, 15> #define DECLARE_AT24C512(instance) EEPROM24<typeof(instance), instance, 128, 16> #define DECLARE_AT24CM01(instance) EEPROM24<typeof(instance), instance, 256, 17> #define DECLARE_AT24CM02(instance) EEPROM24<typeof(instance), instance, 256, 18> #define DECLARE_EEPROM24(instance, page_size, addr_bits) EEPROM24<typeof(instance), instance, page_size, addr_bits> template<typename T, T& WIRE, size_t PAGE_SIZE, size_t ADDR_BITS> class EEPROM24 { public: static constexpr uint32_t WIRE_CLOCK = 400000; enum { ERR_NONE = 0, ERR_IO = 4, ERR_ARG = 8, }; void begin(uint8_t index = 0, uint8_t nchips = 1) { /* Initialize Wire with setup() */ uint8_t mchips; if (ADDR_BITS <= 16) { index &= 7; mchips = 8 - index; _address = DEVICE | index; } else if (ADDR_BITS <= 18) { index &= (1 << (19 - ADDR_BITS)) - 1; mchips = (20 - ADDR_BITS) - index; _address = DEVICE | (index << (ADDR_BITS - 16)); } else { mchips = 0; _address = DEVICE; } _romsize = (1UL << ADDR_BITS) * (nchips <= mchips ? nchips : mchips); _errcode = 0; } bool read(uint32_t addr, void *buf, size_t len) { if ((addr + len > _romsize) || (!buf && len)) { _errcode = ERR_ARG; return false; } uint8_t *ptr = (uint8_t *)buf; while (len) { size_t n = PAGE_SIZE - (addr & (PAGE_SIZE - 1)); if (len < n) n = len; if (!read0(addr, ptr, n)) return false; ptr += n; addr += n; len -= n; } _errcode = ERR_NONE; return true; } bool write(uint32_t addr, const void *buf, size_t len) { if ((addr + len > _romsize) || (!buf && len)) { _errcode = ERR_ARG; return false; } const uint8_t *ptr = (const uint8_t *)buf; while (len) { size_t n = PAGE_SIZE - (addr & (PAGE_SIZE - 1)); if (len < n) n = len; if (!write0(addr, ptr, n)) return false; ptr += n; addr += n; len -= n; delay(20); } _errcode = ERR_NONE; return true; } int errcode(void) { return _errcode; } private: uint8_t devaddr(uint32_t addr) { return (_address & ~7) | ((_address + (addr >> (ADDR_BITS <= 16 ? ADDR_BITS : 16))) & 7); } bool read0(uint32_t addr, void *buf, size_t len) { if (!write0(addr, nullptr, 0, false)) return false; WIRE.requestFrom(devaddr(addr), len); return (_errcode = WIRE.readBytes((uint8_t *)buf, len) == len ? ERR_NONE : ERR_IO) == ERR_NONE; } bool write0(uint32_t addr, const void *buf, size_t len, uint8_t sendStop = true) { WIRE.beginTransmission(devaddr(addr)); if ((_errcode = WIRE.endTransmission(false)) != ERR_NONE) return false; if (ADDR_BITS < 12) { /* AT24C01 - AT24C16 */ uint8_t wordaddr[] = { (uint8_t)addr }; WIRE.beginTransmission(devaddr(addr)); WIRE.write(wordaddr, sizeof(wordaddr)); } else { /* AT24C32 - AT24CM02 */ uint8_t wordaddr[] = { (uint8_t)(addr >> 8), (uint8_t)addr }; WIRE.beginTransmission(devaddr(addr)); WIRE.write(wordaddr, sizeof(wordaddr)); } if (buf && len) WIRE.write((const uint8_t *)buf, len); return (_errcode = WIRE.endTransmission(sendStop)) == ERR_NONE; } static constexpr uint8_t DEVICE = 0x50; uint8_t _address; uint32_t _romsize; int _errcode; }; |