update for ci test shield
Fork of I2CEeprom by
Diff: I2CEeprom.h
- Revision:
- 1:b23f5561266c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/I2CEeprom.h Sun Jul 19 09:34:04 2015 +0000 @@ -0,0 +1,108 @@ +/* Simple access class for I2C EEPROM chips like Microchip 24LC + * Copyright (c) 2015 Robin Hourahane + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#ifndef __I2CEEPROM_H__ +#define __I2CEEPROM_H__ + +#include <mbed.h> + +/// 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. +/// The class handles multiple page writes so any amount of data can be written in +/// a single call to write. The writes are not buffered so additional memory use +/// is kept to a minimum. +/// +/// Although not tested it should work with the MAC versions of Microchip range +/// as well but the chipSize will need to be set to include the ROM area as well. +class I2CEeprom { +public: + /// Constructor to create a new instance of the class. + /// @param sda The pin name for the sda line of the I2C bus. + /// @param scl The pin name for the scl line of the I2C bus. + /// @param address The 8bit I2C address of the chip in the range 0xA0 - 0xAE. + /// @param pageSize The size of the page used in writing to the chip. + /// @param chipSize The size of the memory in the chip to allow range checkng. Set to + /// 0 to disable checks. + /// @param busSpeed The frequency of the I2C bus defaults to 400K. + I2CEeprom(PinName sda, PinName scl, int address, size_t pageSize, size_t chipSize, int busSpeed = 400000); + + /// Read a single byte from the address in memory. + /// @param address Memory address to read from. + /// @param value Variable to receive value read. + /// @returns Number of bytes read from memory. + size_t read(size_t address, char &value); + + /// Read multiple bytes starting from the address in memory. + /// @param address Memory address to start reading from. + /// @param buffer Pointer to buffer to hold bytes read from memory. + /// @param size Number of bytes to be read from memory. + /// @returns Number of bytes read from memory. + size_t read(size_t address, char *buffer, size_t size); + + /// Read either an instance or an array of a POD type from memory. + /// Note the value of the type can't contain pointers. + /// @param address Start address for reading memory. + /// @param value Object to be read from memory. + /// @returns Number of bytes read from memory. + template<typename T> size_t read(size_t address, T &value) { + return read(address, reinterpret_cast<char *>(&value), sizeof(T)); + } + + /// Write a single byte to the address in memory. + /// @param address Memory address to write to. + /// @param value Value to be written to memory. + /// @returns Number of bytes written to memory. + size_t write(size_t address, char value); + + /// Write multiple bytes starting from the address in memory. + /// @param address Memory address to start writting to. + /// @param buffer Pointer to buffer holding the bytes to write to memory. + /// @param size Number of bytes to be written to memory. + /// @returns Number of bytes written to memory. + size_t write(size_t address, const char *buffer, size_t size); + + /// Write either an instance or an array of a POD type to memory. + /// Note the value of the type can't contain pointers. + /// @param address Start address to write to memory. + /// @returns Number of bytes written to memory. + template<typename T> size_t write(size_t address, const T &value) { + return write(address, reinterpret_cast<const char *>(&value), sizeof(T)); + } + + /// Fill a range of memory with a single value. No memory is allocated + /// so large areas can be filled with minimal memory usage. + /// @param address Starting address to write to. + /// @param value Value to be written to memory. + /// @Param size Number of bytes to be written. + /// @returns Number of bytes written to memory. + size_t fill(size_t address, char value, size_t size); + +private: + // Wait for a write cycle to complete using polling and small waits. + void waitForWrite(); + + // Validate that the proposed opperation will fit in the size of + // the chip. + bool checkSpace(size_t address, size_t size); + +private: + I2C m_i2c; + int m_i2cAddress; + size_t m_chipSize; + size_t m_pageSize; +}; + +#endif \ No newline at end of file