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CommandStation-EX/I2CManager.h
Neil McKechnie 43319fd3dd Add I2C support functions
Add new read/write functions to I2CManager class, and modify the LCD, OLED and PWM classes to use them effectively.
2021-03-31 12:19:55 +01:00

76 lines
2.6 KiB
C++

/*
* © 2021, Neil McKechnie. All rights reserved.
*
* This file is part of CommandStation-EX
*
* This 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.
*
* It 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 CommandStation. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef I2CManager_h
#define I2CManager_h
#include "FSH.h"
/*
* Helper class to manage access to the I2C 'Wire' subsystem.
*
* Helps to avoid calling Wire.begin() multiple times (which is not)
* entirely benign as it reinitialises).
*
* Also helps to avoid the Wire clock from being set, by another device
* driver, to a speed which is higher than a device supports.
*
* Thirdly, it provides a convenient way to check whether there is a
* device on a particular I2C address.
*/
class I2CManagerClass {
public:
I2CManagerClass() {}
// If not already initialised, initialise I2C (wire).
void begin(void);
// Set clock speed to the lowest requested one.
void setClock(uint32_t speed);
// Force clock speed
void forceClock(uint32_t speed);
// Check if specified I2C address is responding.
uint8_t checkAddress(uint8_t address);
bool exists(uint8_t address);
// Write a complete transmission to I2C from an array in RAM
uint8_t write(uint8_t address, const uint8_t buffer[], uint8_t size);
// Write a complete transmission to I2C from an array in Flash
uint8_t write_P(uint8_t address, const uint8_t buffer[], uint8_t size);
// Write a transmission to I2C from a list of bytes.
uint8_t write(uint8_t address, int nBytes, ...);
// Write a command from an array in RAM and read response
uint8_t read(uint8_t address, uint8_t writeBuffer[], uint8_t writeSize,
uint8_t readBuffer[], uint8_t readSize);
// Write a command from an arbitrary list of bytes and read response
uint8_t read(uint8_t address, uint8_t readBuffer[], uint8_t readSize,
uint8_t writeSize, ...);
// Write a null command and read the response.
uint8_t read(uint8_t address, uint8_t readBuffer[], uint8_t readSize);
private:
bool _beginCompleted = false;
bool _clockSpeedFixed = false;
uint32_t _clockSpeed = 400000L; // 400kHz max on Arduino.
};
extern I2CManagerClass I2CManager;
#endif