/** library to communicate using I²C as master * @file * @author King Kévin * @copyright SPDX-License-Identifier: GPL-3.0-or-later * @date 2017-2021 * @warning the I²C peripheral is very glitchy (sending random clock pulses), thus prefer the software implementation alternative, which is simpler, more flexible, smaller, and very stable (it just draws more energy) */ #pragma once /** I²C return codes */ enum i2c_master_rc { I2C_MASTER_RC_NONE = 0, /**< no error */ I2C_MASTER_RC_START_STOP_IN_PROGESS, /**< a start or stop condition is already in progress */ I2C_MASTER_RC_NOT_MASTER, /**< not in master mode */ I2C_MASTER_RC_NOT_TRANSMIT, /**< not in transmit mode */ I2C_MASTER_RC_NOT_RECEIVE, /**< not in receive mode */ I2C_MASTER_RC_NOT_READY, /**< slave is not read (previous operations has been NACKed) */ I2C_MASTER_RC_NAK, /**< not acknowledge received */ I2C_MASTER_RC_BUS_ERROR, /**< an error on the I²C bus occurred */ I2C_MASTER_RC_TIMEOUT, /**< a timeout has occurred because an operation has not completed in the expected time */ I2C_MASTER_RC_OTHER, /** any other error (does not have to be I²C related) */ }; /** setup I²C peripheral * @param[in] freq_khz desired clock frequency, in kHz * @return if I²C bus is ready to be used (same as i2c_master_check_signals) */ bool i2c_master_setup(uint16_t freq_khz); /** release I²C peripheral */ void i2c_master_release(void); /** reset I²C peripheral, fixing any locked state * @warning the I²C peripheral needs to be re-setup * @note to be used after failed start or stop, and bus error */ void i2c_master_reset(void); /** check if SDA and SCL signals are pulled high * @return if SDA and SCL signals are pulled high */ bool i2c_master_check_signals(void); /** send start condition * @return I2C return code */ enum i2c_master_rc i2c_master_start(void); /** select I²C slave device * @warning a start condition should be sent before this operation * @param[in] slave I²C address of slave device to select * @param[in] address_10bit if the I²C slave address is 10 bits wide * @param[in] write this transaction will be followed by a read (false) or write (true) operation * @return I²C return code */ enum i2c_master_rc i2c_master_select_slave(uint16_t slave, bool address_10bit, bool write); /** read data over I²C * @param[out] data array to store bytes read * @param[in] data_size number of bytes to read * @return I²C return code * @warning the slave device must be selected before this operation * @note a stop condition will be sent at the end (I²C does not permit multiple reads, and this is necessary for 1-byte transfer) */ enum i2c_master_rc i2c_master_read(uint8_t* data, uint16_t data_size); /** write data over I²C * @param[in] data array of byte to write to slave * @param[in] data_size number of bytes to write * @return I²C return code * @warning the slave device must be selected before this operation * @note no stop condition is sent at the end, allowing multiple writes */ enum i2c_master_rc i2c_master_write(const uint8_t* data, uint16_t data_size); /** sent stop condition * @param[in] i2c I²C base address * @return I²C return code */ enum i2c_master_rc i2c_master_stop(void); /** read data from slave device * @param[in] slave I²C address of slave device to select * @param[in] address_10bit if the I²C slave address is 10 bits wide * @param[out] data array to store bytes read * @param[in] data_size number of bytes to read * @return I²C return code * @note start and stop conditions are included */ enum i2c_master_rc i2c_master_slave_read(uint16_t slave, bool address_10bit, uint8_t* data, uint16_t data_size); /** write data to slave device * @param[in] slave I²C address of slave device to select * @param[in] address_10bit if the I²C slave address is 10 bits wide * @param[in] data array of byte to write to slave * @param[in] data_size number of bytes to write * @return I²C return code * @note start and stop conditions are included */ enum i2c_master_rc i2c_master_slave_write(uint16_t slave, bool address_10bit, const uint8_t* data, uint16_t data_size); /** read data at specific address from an I²C memory slave * @param[in] slave I²C address of slave device to select * @param[in] address_10bit if the I²C slave address is 10 bits wide * @param[in] address memory address of slave to read from * @param[in] address_size address size in bytes * @param[out] data array to store bytes read * @param[in] data_size number of bytes to read * @return I²C return code * @note start and stop conditions are included */ enum i2c_master_rc i2c_master_address_read(uint16_t slave, bool address_10bit, const uint8_t* address, uint16_t address_size, uint8_t* data, uint16_t data_size); /** write data at specific address on an I²C memory slave * @param[in] slave I²C address of slave device to select * @param[in] address_10bit if the I²C slave address is 10 bits wide * @param[in] address memory address of slave to write to * @param[in] address_size address size in bytes * @param[in] data array of byte to write to slave * @param[in] data_size number of bytes to write * @return I²C return code * @note start and stop conditions are included */ enum i2c_master_rc i2c_master_address_write(uint16_t slave, bool address_10bit, const uint8_t* address, uint16_t address_size, const uint8_t* data, uint16_t data_size); /** interrupt service routine used to wake up * @note not sure why the declaration need to be in main for it to work */ void i2c_master_isr(void) __interrupt(IRQ_I2C);