Firmware2/Marlin/src/HAL/I2cEeprom.cpp
2018-02-25 04:38:17 -06:00

161 lines
5.3 KiB
C++

/**
* Marlin 3D Printer Firmware
* Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
*
* 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 <http://www.gnu.org/licenses/>.
*
*/
/**
* Description: functions for I2C connected external EEPROM.
* Not platform dependent.
*/
#include "../inc/MarlinConfig.h"
#if ENABLED(I2C_EEPROM)
// --------------------------------------------------------------------------
// Includes
// --------------------------------------------------------------------------
#include "HAL.h"
#include <Wire.h>
// --------------------------------------------------------------------------
// Externals
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Local defines
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Types
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Variables
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Public Variables
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Private Variables
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Function prototypes
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Private functions
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Public functions
// --------------------------------------------------------------------------
static uint8_t eeprom_device_address = 0x50;
static void eeprom_init(void) {
static bool eeprom_initialised = false;
if (!eeprom_initialised) {
Wire.begin();
eeprom_initialised = true;
}
}
void eeprom_write_byte(unsigned char *pos, unsigned char value) {
unsigned eeprom_address = (unsigned) pos;
eeprom_init();
Wire.beginTransmission(eeprom_device_address);
Wire.write((int)(eeprom_address >> 8)); // MSB
Wire.write((int)(eeprom_address & 0xFF)); // LSB
Wire.write(value);
Wire.endTransmission();
// wait for write cycle to complete
// this could be done more efficiently with "acknowledge polling"
delay(5);
}
// WARNING: address is a page address, 6-bit end will wrap around
// also, data can be maximum of about 30 bytes, because the Wire library has a buffer of 32 bytes
void eeprom_update_block(const void *pos, void* eeprom_address, size_t n) {
eeprom_init();
Wire.beginTransmission(eeprom_device_address);
Wire.write((int)((unsigned)eeprom_address >> 8)); // MSB
Wire.write((int)((unsigned)eeprom_address & 0xFF)); // LSB
Wire.endTransmission();
uint8_t *ptr = (uint8_t*)pos;
uint8_t flag = 0;
Wire.requestFrom(eeprom_device_address, (byte)n);
for (byte c = 0; c < n && Wire.available(); c++)
flag |= Wire.read() ^ ptr[c];
if (flag) {
Wire.beginTransmission(eeprom_device_address);
Wire.write((int)((unsigned)eeprom_address >> 8)); // MSB
Wire.write((int)((unsigned)eeprom_address & 0xFF)); // LSB
Wire.write((uint8_t*)pos, n);
Wire.endTransmission();
// wait for write cycle to complete
// this could be done more efficiently with "acknowledge polling"
delay(5);
}
}
unsigned char eeprom_read_byte(unsigned char *pos) {
byte data = 0xFF;
unsigned eeprom_address = (unsigned)pos;
eeprom_init();
Wire.beginTransmission(eeprom_device_address);
Wire.write((int)(eeprom_address >> 8)); // MSB
Wire.write((int)(eeprom_address & 0xFF)); // LSB
Wire.endTransmission();
Wire.requestFrom(eeprom_device_address, (byte)1);
return Wire.available() ? Wire.read() : 0xFF;
}
// maybe let's not read more than 30 or 32 bytes at a time!
void eeprom_read_block(void* pos, const void* eeprom_address, size_t n) {
eeprom_init();
Wire.beginTransmission(eeprom_device_address);
Wire.write((int)((unsigned)eeprom_address >> 8)); // MSB
Wire.write((int)((unsigned)eeprom_address & 0xFF)); // LSB
Wire.endTransmission();
Wire.requestFrom(eeprom_device_address, (byte)n);
for (byte c = 0; c < n; c++ )
if (Wire.available()) *((uint8_t*)pos + c) = Wire.read();
}
#endif // ENABLED(I2C_EEPROM)