Mateusz Grzywacz / I2CEeprom

Class to provide simple access to I2C EEPROM chiles like Microchip's 24LC range or AMTELS AT24C range. Chips up to 64Kb in size are directly supported.

Dependents:   Nucleo_praktyki

Fork of I2CEeprom by Robin Hourahane

I2CEeprom.h@1:b23f5561266c, 2015-07-19 (annotated)

Committer:
rhourahane
Date:
Sun Jul 19 09:34:04 2015 +0000
Revision:
1:b23f5561266c
Child:
2:b7877755371e
Updates to make library more generic to allow support for more I2C EEPROM chips.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
rhourahane 1:b23f5561266c 1 /* Simple access class for I2C EEPROM chips like Microchip 24LC
rhourahane 1:b23f5561266c 2 * Copyright (c) 2015 Robin Hourahane
rhourahane 1:b23f5561266c 3 *
rhourahane 1:b23f5561266c 4 * Licensed under the Apache License, Version 2.0 (the "License");
rhourahane 1:b23f5561266c 5 * you may not use this file except in compliance with the License.
rhourahane 1:b23f5561266c 6 * You may obtain a copy of the License at
rhourahane 1:b23f5561266c 7 *
rhourahane 1:b23f5561266c 8 * http://www.apache.org/licenses/LICENSE-2.0
rhourahane 1:b23f5561266c 9 *
rhourahane 1:b23f5561266c 10 * Unless required by applicable law or agreed to in writing, software
rhourahane 1:b23f5561266c 11 * distributed under the License is distributed on an "AS IS" BASIS,
rhourahane 1:b23f5561266c 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
rhourahane 1:b23f5561266c 13 * See the License for the specific language governing permissions and
rhourahane 1:b23f5561266c 14 * limitations under the License.
rhourahane 1:b23f5561266c 15 */
rhourahane 1:b23f5561266c 16 #ifndef __I2CEEPROM_H__
rhourahane 1:b23f5561266c 17 #define __I2CEEPROM_H__
rhourahane 1:b23f5561266c 18
rhourahane 1:b23f5561266c 19 #include <mbed.h>
rhourahane 1:b23f5561266c 20
rhourahane 1:b23f5561266c 21 /// Class to provide simple access to I2C EEPROM chiles like Microchip's 24LC range
rhourahane 1:b23f5561266c 22 /// or AMTELS AT24C range.
rhourahane 1:b23f5561266c 23 /// Chips up to 64Kb in size are directly supported.
rhourahane 1:b23f5561266c 24 /// The class handles multiple page writes so any amount of data can be written in
rhourahane 1:b23f5561266c 25 /// a single call to write. The writes are not buffered so additional memory use
rhourahane 1:b23f5561266c 26 /// is kept to a minimum.
rhourahane 1:b23f5561266c 27 ///
rhourahane 1:b23f5561266c 28 /// Although not tested it should work with the MAC versions of Microchip range
rhourahane 1:b23f5561266c 29 /// as well but the chipSize will need to be set to include the ROM area as well.
rhourahane 1:b23f5561266c 30 class I2CEeprom {
rhourahane 1:b23f5561266c 31 public:
rhourahane 1:b23f5561266c 32 /// Constructor to create a new instance of the class.
rhourahane 1:b23f5561266c 33 /// @param sda The pin name for the sda line of the I2C bus.
rhourahane 1:b23f5561266c 34 /// @param scl The pin name for the scl line of the I2C bus.
rhourahane 1:b23f5561266c 35 /// @param address The 8bit I2C address of the chip in the range 0xA0 - 0xAE.
rhourahane 1:b23f5561266c 36 /// @param pageSize The size of the page used in writing to the chip.
rhourahane 1:b23f5561266c 37 /// @param chipSize The size of the memory in the chip to allow range checkng. Set to
rhourahane 1:b23f5561266c 38 /// 0 to disable checks.
rhourahane 1:b23f5561266c 39 /// @param busSpeed The frequency of the I2C bus defaults to 400K.
rhourahane 1:b23f5561266c 40 I2CEeprom(PinName sda, PinName scl, int address, size_t pageSize, size_t chipSize, int busSpeed = 400000);
rhourahane 1:b23f5561266c 41
rhourahane 1:b23f5561266c 42 /// Read a single byte from the address in memory.
rhourahane 1:b23f5561266c 43 /// @param address Memory address to read from.
rhourahane 1:b23f5561266c 44 /// @param value Variable to receive value read.
rhourahane 1:b23f5561266c 45 /// @returns Number of bytes read from memory.
rhourahane 1:b23f5561266c 46 size_t read(size_t address, char &value);
rhourahane 1:b23f5561266c 47
rhourahane 1:b23f5561266c 48 /// Read multiple bytes starting from the address in memory.
rhourahane 1:b23f5561266c 49 /// @param address Memory address to start reading from.
rhourahane 1:b23f5561266c 50 /// @param buffer Pointer to buffer to hold bytes read from memory.
rhourahane 1:b23f5561266c 51 /// @param size Number of bytes to be read from memory.
rhourahane 1:b23f5561266c 52 /// @returns Number of bytes read from memory.
rhourahane 1:b23f5561266c 53 size_t read(size_t address, char *buffer, size_t size);
rhourahane 1:b23f5561266c 54
rhourahane 1:b23f5561266c 55 /// Read either an instance or an array of a POD type from memory.
rhourahane 1:b23f5561266c 56 /// Note the value of the type can't contain pointers.
rhourahane 1:b23f5561266c 57 /// @param address Start address for reading memory.
rhourahane 1:b23f5561266c 58 /// @param value Object to be read from memory.
rhourahane 1:b23f5561266c 59 /// @returns Number of bytes read from memory.
rhourahane 1:b23f5561266c 60 template<typename T> size_t read(size_t address, T &value) {
rhourahane 1:b23f5561266c 61 return read(address, reinterpret_cast<char *>(&value), sizeof(T));
rhourahane 1:b23f5561266c 62 }
rhourahane 1:b23f5561266c 63
rhourahane 1:b23f5561266c 64 /// Write a single byte to the address in memory.
rhourahane 1:b23f5561266c 65 /// @param address Memory address to write to.
rhourahane 1:b23f5561266c 66 /// @param value Value to be written to memory.
rhourahane 1:b23f5561266c 67 /// @returns Number of bytes written to memory.
rhourahane 1:b23f5561266c 68 size_t write(size_t address, char value);
rhourahane 1:b23f5561266c 69
rhourahane 1:b23f5561266c 70 /// Write multiple bytes starting from the address in memory.
rhourahane 1:b23f5561266c 71 /// @param address Memory address to start writting to.
rhourahane 1:b23f5561266c 72 /// @param buffer Pointer to buffer holding the bytes to write to memory.
rhourahane 1:b23f5561266c 73 /// @param size Number of bytes to be written to memory.
rhourahane 1:b23f5561266c 74 /// @returns Number of bytes written to memory.
rhourahane 1:b23f5561266c 75 size_t write(size_t address, const char *buffer, size_t size);
rhourahane 1:b23f5561266c 76
rhourahane 1:b23f5561266c 77 /// Write either an instance or an array of a POD type to memory.
rhourahane 1:b23f5561266c 78 /// Note the value of the type can't contain pointers.
rhourahane 1:b23f5561266c 79 /// @param address Start address to write to memory.
rhourahane 1:b23f5561266c 80 /// @returns Number of bytes written to memory.
rhourahane 1:b23f5561266c 81 template<typename T> size_t write(size_t address, const T &value) {
rhourahane 1:b23f5561266c 82 return write(address, reinterpret_cast<const char *>(&value), sizeof(T));
rhourahane 1:b23f5561266c 83 }
rhourahane 1:b23f5561266c 84
rhourahane 1:b23f5561266c 85 /// Fill a range of memory with a single value. No memory is allocated
rhourahane 1:b23f5561266c 86 /// so large areas can be filled with minimal memory usage.
rhourahane 1:b23f5561266c 87 /// @param address Starting address to write to.
rhourahane 1:b23f5561266c 88 /// @param value Value to be written to memory.
rhourahane 1:b23f5561266c 89 /// @Param size Number of bytes to be written.
rhourahane 1:b23f5561266c 90 /// @returns Number of bytes written to memory.
rhourahane 1:b23f5561266c 91 size_t fill(size_t address, char value, size_t size);
rhourahane 1:b23f5561266c 92
rhourahane 1:b23f5561266c 93 private:
rhourahane 1:b23f5561266c 94 // Wait for a write cycle to complete using polling and small waits.
rhourahane 1:b23f5561266c 95 void waitForWrite();
rhourahane 1:b23f5561266c 96
rhourahane 1:b23f5561266c 97 // Validate that the proposed opperation will fit in the size of
rhourahane 1:b23f5561266c 98 // the chip.
rhourahane 1:b23f5561266c 99 bool checkSpace(size_t address, size_t size);
rhourahane 1:b23f5561266c 100
rhourahane 1:b23f5561266c 101 private:
rhourahane 1:b23f5561266c 102 I2C m_i2c;
rhourahane 1:b23f5561266c 103 int m_i2cAddress;
rhourahane 1:b23f5561266c 104 size_t m_chipSize;
rhourahane 1:b23f5561266c 105 size_t m_pageSize;
rhourahane 1:b23f5561266c 106 };
rhourahane 1:b23f5561266c 107
rhourahane 1:b23f5561266c 108 #endif