Jon Buckman / I2CEEPROM

Update current library to accommodate small devices.

I2CEEPROM.h@10:839cd28531dd, 2019-02-27 (annotated)

Committer:
jonebuckman
Date:
Wed Feb 27 22:22:16 2019 +0000
Revision:
10:839cd28531dd
Parent:
9:26b4bcc5d3b5 
Added type cast (char)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jonebuckman 0:bcc1f1890330 1 /* Simple access class for I2C EEPROM chips like Microchip 24LC
jonebuckman 9:26b4bcc5d3b5 2 * Copyright (c) 2016 Jon Buckman
jonebuckman 0:bcc1f1890330 3 * Copyright (c) 2015 Robin Hourahane
jonebuckman 0:bcc1f1890330 4 *
jonebuckman 0:bcc1f1890330 5 * Licensed under the Apache License, Version 2.0 (the "License");
jonebuckman 0:bcc1f1890330 6 * you may not use this file except in compliance with the License.
jonebuckman 0:bcc1f1890330 7 * You may obtain a copy of the License at
jonebuckman 0:bcc1f1890330 8 *
jonebuckman 0:bcc1f1890330 9 * http://www.apache.org/licenses/LICENSE-2.0
jonebuckman 0:bcc1f1890330 10 *
jonebuckman 0:bcc1f1890330 11 * Unless required by applicable law or agreed to in writing, software
jonebuckman 0:bcc1f1890330 12 * distributed under the License is distributed on an "AS IS" BASIS,
jonebuckman 0:bcc1f1890330 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
jonebuckman 0:bcc1f1890330 14 * See the License for the specific language governing permissions and
jonebuckman 0:bcc1f1890330 15 * limitations under the License.
jonebuckman 0:bcc1f1890330 16 */
jonebuckman 0:bcc1f1890330 17 #ifndef __I2CEEPROM_H__
jonebuckman 0:bcc1f1890330 18 #define __I2CEEPROM_H__
jonebuckman 0:bcc1f1890330 19
jonebuckman 0:bcc1f1890330 20 #include <mbed.h>
jonebuckman 0:bcc1f1890330 21
jonebuckman 0:bcc1f1890330 22 /// Class to provide simple access to I2C EEPROM chiles like Microchip's 24LC range
jonebuckman 0:bcc1f1890330 23 /// or AMTELS AT24C range.
jonebuckman 0:bcc1f1890330 24 /// Chips up to 64Kb in size are directly supported.
jonebuckman 0:bcc1f1890330 25 /// The class handles multiple page writes so any amount of data can be written in
jonebuckman 0:bcc1f1890330 26 /// a single call to write. The writes are not buffered so additional memory use
jonebuckman 0:bcc1f1890330 27 /// is kept to a minimum.
jonebuckman 0:bcc1f1890330 28 ///
jonebuckman 0:bcc1f1890330 29 /// Although not tested it should work with the MAC versions of Microchip range
jonebuckman 0:bcc1f1890330 30 /// as well but the chipSize will need to be set to include the ROM area as well.
jonebuckman 0:bcc1f1890330 31 class I2CEEPROM {
jonebuckman 0:bcc1f1890330 32 public:
jonebuckman 0:bcc1f1890330 33 /// Constructor to create a new instance of the class.
jonebuckman 0:bcc1f1890330 34 /// @param sda The pin name for the sda line of the I2C bus.
jonebuckman 0:bcc1f1890330 35 /// @param scl The pin name for the scl line of the I2C bus.
jonebuckman 0:bcc1f1890330 36 /// @param address The 8bit I2C address of the chip in the range 0xA0 - 0xAE.
jonebuckman 0:bcc1f1890330 37 /// @param pageSize The size of the page used in writing to the chip.
jonebuckman 0:bcc1f1890330 38 /// @param chipSize The size of the memory in the chip to allow range checkng. Set to
jonebuckman 0:bcc1f1890330 39 /// 0 to disable checks.
jonebuckman 0:bcc1f1890330 40 /// @param busSpeed The frequency of the I2C bus defaults to 400K.
jonebuckman 0:bcc1f1890330 41 I2CEEPROM(PinName sda, PinName scl, int address, size_t pageSize, size_t chipSize, int busSpeed = 400000);
jonebuckman 0:bcc1f1890330 42
jonebuckman 0:bcc1f1890330 43 /// Read a single byte from the address in memory.
jonebuckman 0:bcc1f1890330 44 /// @param address Memory address to read from.
jonebuckman 0:bcc1f1890330 45 /// @param value Variable to receive value read.
jonebuckman 0:bcc1f1890330 46 /// @returns Number of bytes read from memory.
jonebuckman 0:bcc1f1890330 47 size_t read(size_t address, char &value);
jonebuckman 0:bcc1f1890330 48
jonebuckman 0:bcc1f1890330 49 /// Read multiple bytes starting from the address in memory.
jonebuckman 0:bcc1f1890330 50 /// @param address Memory address to start reading from.
jonebuckman 0:bcc1f1890330 51 /// @param buffer Pointer to buffer to hold bytes read from memory.
jonebuckman 0:bcc1f1890330 52 /// @param size Number of bytes to be read from memory.
jonebuckman 0:bcc1f1890330 53 /// @returns Number of bytes read from memory.
jonebuckman 0:bcc1f1890330 54 size_t read(size_t address, char *buffer, size_t size);
jonebuckman 0:bcc1f1890330 55
jonebuckman 0:bcc1f1890330 56 /// Read either an instance or an array of a POD type from memory.
jonebuckman 0:bcc1f1890330 57 /// Note the value of the type can't contain pointers.
jonebuckman 0:bcc1f1890330 58 /// @param address Start address for reading memory.
jonebuckman 0:bcc1f1890330 59 /// @param value Object to be read from memory.
jonebuckman 0:bcc1f1890330 60 /// @returns Number of bytes read from memory.
jonebuckman 0:bcc1f1890330 61 template<typename T> size_t read(size_t address, T &value) {
jonebuckman 0:bcc1f1890330 62 return read(address, reinterpret_cast<char *>(&value), sizeof(T));
jonebuckman 0:bcc1f1890330 63 }
jonebuckman 0:bcc1f1890330 64
jonebuckman 0:bcc1f1890330 65 /// Write a single byte to the address in memory.
jonebuckman 0:bcc1f1890330 66 /// @param address Memory address to write to.
jonebuckman 0:bcc1f1890330 67 /// @param value Value to be written to memory.
jonebuckman 0:bcc1f1890330 68 /// @returns Number of bytes written to memory.
jonebuckman 0:bcc1f1890330 69 size_t write(size_t address, char value);
jonebuckman 0:bcc1f1890330 70
jonebuckman 0:bcc1f1890330 71 /// Write multiple bytes starting from the address in memory.
jonebuckman 0:bcc1f1890330 72 /// @param address Memory address to start writting to.
jonebuckman 0:bcc1f1890330 73 /// @param buffer Pointer to buffer holding the bytes to write to memory.
jonebuckman 0:bcc1f1890330 74 /// @param size Number of bytes to be written to memory.
jonebuckman 0:bcc1f1890330 75 /// @returns Number of bytes written to memory.
jonebuckman 0:bcc1f1890330 76 size_t write(size_t address, const char *buffer, size_t size);
jonebuckman 0:bcc1f1890330 77
jonebuckman 0:bcc1f1890330 78 /// Write either an instance or an array of a POD type to memory.
jonebuckman 0:bcc1f1890330 79 /// Note the value of the type can't contain pointers.
jonebuckman 0:bcc1f1890330 80 /// @param address Start address to write to memory.
jonebuckman 0:bcc1f1890330 81 /// @returns Number of bytes written to memory.
jonebuckman 0:bcc1f1890330 82 template<typename T> size_t write(size_t address, const T &value) {
jonebuckman 0:bcc1f1890330 83 return write(address, reinterpret_cast<const char *>(&value), sizeof(T));
jonebuckman 0:bcc1f1890330 84 }
jonebuckman 0:bcc1f1890330 85
jonebuckman 0:bcc1f1890330 86 /// Fill a range of memory with a single value. No memory is allocated
jonebuckman 0:bcc1f1890330 87 /// so large areas can be filled with minimal memory usage.
jonebuckman 0:bcc1f1890330 88 /// @param address Starting address to write to.
jonebuckman 0:bcc1f1890330 89 /// @param value Value to be written to memory.
jonebuckman 0:bcc1f1890330 90 /// @Param size Number of bytes to be written.
jonebuckman 0:bcc1f1890330 91 /// @returns Number of bytes written to memory.
jonebuckman 0:bcc1f1890330 92 size_t fill(size_t address, char value, size_t size);
jonebuckman 0:bcc1f1890330 93
jonebuckman 0:bcc1f1890330 94 private:
jonebuckman 0:bcc1f1890330 95 // Wait for a write cycle to complete using polling and small waits.
jonebuckman 0:bcc1f1890330 96 void waitForWrite();
jonebuckman 0:bcc1f1890330 97
jonebuckman 0:bcc1f1890330 98 // Validate that the proposed opperation will fit in the size of
jonebuckman 0:bcc1f1890330 99 // the chip.
jonebuckman 0:bcc1f1890330 100 bool checkSpace(size_t address, size_t size);
jonebuckman 0:bcc1f1890330 101
jonebuckman 0:bcc1f1890330 102 private:
jonebuckman 0:bcc1f1890330 103 I2C m_i2c;
jonebuckman 0:bcc1f1890330 104 int m_i2cAddress;
jonebuckman 0:bcc1f1890330 105 size_t m_chipSize;
jonebuckman 0:bcc1f1890330 106 size_t m_pageSize;
jonebuckman 0:bcc1f1890330 107 };
jonebuckman 0:bcc1f1890330 108
jonebuckman 0:bcc1f1890330 109 #endif