Pico_I2C_Lib/Pico_I2C.c

108 lines
2.8 KiB
C

#include "Pico_I2C.h"
#include <hardware/gpio.h>
#include <hardware/i2c.h>
#include <pico/i2c_slave.h>
#include "Config.h"
#include <stdio.h>
void init_i2c_master(i2c_master_t *i2c_master, i2c_inst_t *i2c_inst)
{
i2c_master->i2c_inst = i2c_inst;
// Init GPIO pins
gpio_init(I2C_MASTER_SDA_PIN);
gpio_init(I2C_MASTER_SCL_PIN);
gpio_set_function(I2C_MASTER_SDA_PIN, GPIO_FUNC_I2C);
gpio_set_function(I2C_MASTER_SCL_PIN, GPIO_FUNC_I2C);
gpio_pull_up(I2C_MASTER_SDA_PIN);
gpio_pull_up(I2C_MASTER_SCL_PIN);
i2c_init(i2c_master->i2c_inst, I2C_MASTER_BAUD_RATE);
}
void exit_i2c_master(i2c_master_t *i2c_master)
{
// Reset GPIO pins
gpio_deinit(I2C_MASTER_SDA_PIN);
gpio_deinit(I2C_MASTER_SCL_PIN);
gpio_set_function(I2C_MASTER_SDA_PIN, GPIO_FUNC_NULL);
gpio_set_function(I2C_MASTER_SCL_PIN, GPIO_FUNC_NULL);
i2c_deinit(i2c_master->i2c_inst);
}
static i2c_slave_t *i2c_slaves[2];
static inline void i2c_slave_buffer_handler(i2c_inst_t *i2c, i2c_slave_event_t event)
{
i2c_slave_t *i2c_slave = i2c_slaves[i2c_get_index(i2c)];
switch(event)
{
case I2C_SLAVE_RECEIVE: // master has written some data
if(!i2c_slave->reg_written)
{
// writes always start with the memory address
i2c_slave->reg = i2c_read_byte_raw(i2c);
i2c_slave->reg_written = true;
}
else
{
// save into memory
i2c_slave->buffer[i2c_slave->reg] = i2c_read_byte_raw(i2c);
i2c_slave->reg++;
}
break;
case I2C_SLAVE_REQUEST: // master is requesting data
// load from memory
i2c_write_byte_raw(i2c, i2c_slave->buffer[i2c_slave->reg]);
i2c_slave->reg++;
break;
case I2C_SLAVE_FINISH: // master has signalled Stop / Restart
i2c_slave->reg_written = false;
break;
default:
break;
}
}
void init_i2c_slave(i2c_slave_t *i2c_slave, i2c_inst_t *i2c_inst, uint8_t address)
{
i2c_slave->i2c_inst = i2c_inst;
i2c_slaves[i2c_get_index(i2c_inst)] = i2c_slave;
// Init GPIO pins
gpio_init(I2C_SLAVE_SDA_PIN);
gpio_init(I2C_SLAVE_SCL_PIN);
gpio_set_function(I2C_SLAVE_SDA_PIN, GPIO_FUNC_I2C);
gpio_set_function(I2C_SLAVE_SCL_PIN, GPIO_FUNC_I2C);
i2c_init(i2c_slave->i2c_inst, 0);
// New SDK method to init i2c slave
i2c_slave_init(i2c_slave->i2c_inst, address, &i2c_slave_buffer_handler);
}
void exit_i2c_slave(i2c_slave_t *i2c_slave)
{
// Reset GPIO pins
gpio_deinit(I2C_SLAVE_SDA_PIN);
gpio_deinit(I2C_SLAVE_SCL_PIN);
gpio_set_function(I2C_SLAVE_SDA_PIN, GPIO_FUNC_NULL);
gpio_set_function(I2C_SLAVE_SCL_PIN, GPIO_FUNC_NULL);
// New SDK method to reset i2c slave
i2c_slave_deinit(i2c_slave->i2c_inst);
i2c_deinit(i2c_slave->i2c_inst);
}