303 lines
12 KiB
C
303 lines
12 KiB
C
/* i2c - Example
|
|
|
|
For other examples please check:
|
|
https://github.com/espressif/esp-idf/tree/master/examples
|
|
|
|
This example code is in the Public Domain (or CC0 licensed, at your option.)
|
|
|
|
Unless required by applicable law or agreed to in writing, this
|
|
software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
|
|
CONDITIONS OF ANY KIND, either express or implied.
|
|
*/
|
|
#include <stdio.h>
|
|
#include "driver/i2c.h"
|
|
|
|
/**
|
|
* TEST CODE BRIEF
|
|
*
|
|
* This example will show you how to use I2C module by running two tasks on i2c bus:
|
|
*
|
|
* - read external i2c sensor, here we use a BH1750 light sensor(GY-30 module) for instance.
|
|
* - Use one I2C port(master mode) to read or write the other I2C port(slave mode) on one ESP32 chip.
|
|
*
|
|
* Pin assignment:
|
|
*
|
|
* - slave :
|
|
* GPIO25 is assigned as the data signal of i2c slave port
|
|
* GPIO26 is assigned as the clock signal of i2c slave port
|
|
* - master:
|
|
* GPIO18 is assigned as the data signal of i2c master port
|
|
* GPIO19 is assigned as the clock signal of i2c master port
|
|
*
|
|
* Connection:
|
|
*
|
|
* - connect GPIO18 with GPIO25
|
|
* - connect GPIO19 with GPIO26
|
|
* - connect sda/scl of sensor with GPIO18/GPIO19
|
|
* - no need to add external pull-up resistors, driver will enable internal pull-up resistors.
|
|
*
|
|
* Test items:
|
|
*
|
|
* - read the sensor data, if connected.
|
|
* - i2c master(ESP32) will write data to i2c slave(ESP32).
|
|
* - i2c master(ESP32) will read data from i2c slave(ESP32).
|
|
*/
|
|
|
|
#define DATA_LENGTH 512 /*!<Data buffer length for test buffer*/
|
|
#define RW_TEST_LENGTH 129 /*!<Data length for r/w test, any value from 0-DATA_LENGTH*/
|
|
#define DELAY_TIME_BETWEEN_ITEMS_MS 1234 /*!< delay time between different test items */
|
|
|
|
#define I2C_SLAVE_SCL_IO 26 /*!<gpio number for i2c slave clock */
|
|
#define I2C_SLAVE_SDA_IO 25 /*!<gpio number for i2c slave data */
|
|
#define I2C_SLAVE_NUM I2C_NUM_0 /*!<I2C port number for slave dev */
|
|
#define I2C_SLAVE_TX_BUF_LEN (2*DATA_LENGTH) /*!<I2C slave tx buffer size */
|
|
#define I2C_SLAVE_RX_BUF_LEN (2*DATA_LENGTH) /*!<I2C slave rx buffer size */
|
|
|
|
#define I2C_MASTER_SCL_IO 19 /*!< gpio number for I2C master clock */
|
|
#define I2C_MASTER_SDA_IO 18 /*!< gpio number for I2C master data */
|
|
#define I2C_MASTER_NUM I2C_NUM_1 /*!< I2C port number for master dev */
|
|
#define I2C_MASTER_TX_BUF_DISABLE 0 /*!< I2C master do not need buffer */
|
|
#define I2C_MASTER_RX_BUF_DISABLE 0 /*!< I2C master do not need buffer */
|
|
#define I2C_MASTER_FREQ_HZ 100000 /*!< I2C master clock frequency */
|
|
|
|
#define BH1750_SENSOR_ADDR 0x23 /*!< slave address for BH1750 sensor */
|
|
#define BH1750_CMD_START 0x23 /*!< Command to set measure mode */
|
|
#define ESP_SLAVE_ADDR 0x28 /*!< ESP32 slave address, you can set any 7bit value */
|
|
#define WRITE_BIT I2C_MASTER_WRITE /*!< I2C master write */
|
|
#define READ_BIT I2C_MASTER_READ /*!< I2C master read */
|
|
#define ACK_CHECK_EN 0x1 /*!< I2C master will check ack from slave*/
|
|
#define ACK_CHECK_DIS 0x0 /*!< I2C master will not check ack from slave */
|
|
#define ACK_VAL 0x0 /*!< I2C ack value */
|
|
#define NACK_VAL 0x1 /*!< I2C nack value */
|
|
|
|
xSemaphoreHandle print_mux;
|
|
|
|
/**
|
|
* @brief test code to read esp-i2c-slave
|
|
* We need to fill the buffer of esp slave device, then master can read them out.
|
|
*
|
|
* _______________________________________________________________________________________
|
|
* | start | slave_addr + rd_bit +ack | read n-1 bytes + ack | read 1 byte + nack | stop |
|
|
* --------|--------------------------|----------------------|--------------------|------|
|
|
*
|
|
*/
|
|
esp_err_t i2c_master_read_slave(i2c_port_t i2c_num, uint8_t* data_rd, size_t size)
|
|
{
|
|
if (size == 0) {
|
|
return ESP_OK;
|
|
}
|
|
i2c_cmd_handle_t cmd = i2c_cmd_link_create();
|
|
i2c_master_start(cmd);
|
|
i2c_master_write_byte(cmd, ( ESP_SLAVE_ADDR << 1 ) | READ_BIT, ACK_CHECK_EN);
|
|
if (size > 1) {
|
|
i2c_master_read(cmd, data_rd, size - 1, ACK_VAL);
|
|
}
|
|
i2c_master_read_byte(cmd, data_rd + size - 1, NACK_VAL);
|
|
i2c_master_stop(cmd);
|
|
esp_err_t ret = i2c_master_cmd_begin(i2c_num, cmd, 1000 / portTICK_RATE_MS);
|
|
i2c_cmd_link_delete(cmd);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* @brief Test code to write esp-i2c-slave
|
|
* Master device write data to slave(both esp32),
|
|
* the data will be stored in slave buffer.
|
|
* We can read them out from slave buffer.
|
|
*
|
|
* ___________________________________________________________________
|
|
* | start | slave_addr + wr_bit + ack | write n bytes + ack | stop |
|
|
* --------|---------------------------|----------------------|------|
|
|
*
|
|
*/
|
|
esp_err_t i2c_master_write_slave(i2c_port_t i2c_num, uint8_t* data_wr, size_t size)
|
|
{
|
|
i2c_cmd_handle_t cmd = i2c_cmd_link_create();
|
|
i2c_master_start(cmd);
|
|
i2c_master_write_byte(cmd, ( ESP_SLAVE_ADDR << 1 ) | WRITE_BIT, ACK_CHECK_EN);
|
|
i2c_master_write(cmd, data_wr, size, ACK_CHECK_EN);
|
|
i2c_master_stop(cmd);
|
|
esp_err_t ret = i2c_master_cmd_begin(i2c_num, cmd, 1000 / portTICK_RATE_MS);
|
|
i2c_cmd_link_delete(cmd);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* @brief test code to write esp-i2c-slave
|
|
*
|
|
* 1. set mode
|
|
* _________________________________________________________________
|
|
* | start | slave_addr + wr_bit + ack | write 1 byte + ack | stop |
|
|
* --------|---------------------------|---------------------|------|
|
|
* 2. wait more than 24 ms
|
|
* 3. read data
|
|
* ______________________________________________________________________________________
|
|
* | start | slave_addr + rd_bit + ack | read 1 byte + ack | read 1 byte + nack | stop |
|
|
* --------|---------------------------|--------------------|--------------------|------|
|
|
*/
|
|
esp_err_t i2c_master_sensor_test(i2c_port_t i2c_num, uint8_t* data_h, uint8_t* data_l)
|
|
{
|
|
i2c_cmd_handle_t cmd = i2c_cmd_link_create();
|
|
i2c_master_start(cmd);
|
|
i2c_master_write_byte(cmd, BH1750_SENSOR_ADDR << 1 | WRITE_BIT, ACK_CHECK_EN);
|
|
i2c_master_write_byte(cmd, BH1750_CMD_START, ACK_CHECK_EN);
|
|
i2c_master_stop(cmd);
|
|
int ret = i2c_master_cmd_begin(i2c_num, cmd, 1000 / portTICK_RATE_MS);
|
|
i2c_cmd_link_delete(cmd);
|
|
if (ret == ESP_FAIL) {
|
|
return ret;
|
|
}
|
|
vTaskDelay(30 / portTICK_RATE_MS);
|
|
|
|
cmd = i2c_cmd_link_create();
|
|
i2c_master_start(cmd);
|
|
i2c_master_write_byte(cmd, BH1750_SENSOR_ADDR << 1 | READ_BIT, ACK_CHECK_EN);
|
|
i2c_master_read_byte(cmd, data_h, ACK_VAL);
|
|
i2c_master_read_byte(cmd, data_l, NACK_VAL);
|
|
i2c_master_stop(cmd);
|
|
ret = i2c_master_cmd_begin(i2c_num, cmd, 1000 / portTICK_RATE_MS);
|
|
i2c_cmd_link_delete(cmd);
|
|
if (ret == ESP_FAIL) {
|
|
return ESP_FAIL;
|
|
}
|
|
return ESP_OK;
|
|
}
|
|
|
|
/**
|
|
* @brief i2c master initialization
|
|
*/
|
|
void i2c_master_init()
|
|
{
|
|
int i2c_master_port = I2C_MASTER_NUM;
|
|
i2c_config_t conf;
|
|
conf.mode = I2C_MODE_MASTER;
|
|
conf.sda_io_num = I2C_MASTER_SDA_IO;
|
|
conf.sda_pullup_en = GPIO_PULLUP_ENABLE;
|
|
conf.scl_io_num = I2C_MASTER_SCL_IO;
|
|
conf.scl_pullup_en = GPIO_PULLUP_ENABLE;
|
|
conf.master.clk_speed = I2C_MASTER_FREQ_HZ;
|
|
i2c_param_config(i2c_master_port, &conf);
|
|
i2c_driver_install(i2c_master_port, conf.mode, I2C_MASTER_RX_BUF_DISABLE, I2C_MASTER_TX_BUF_DISABLE, 0);
|
|
}
|
|
|
|
/**
|
|
* @brief i2c slave initialization
|
|
*/
|
|
void i2c_slave_init()
|
|
{
|
|
int i2c_slave_port = I2C_SLAVE_NUM;
|
|
i2c_config_t conf_slave;
|
|
conf_slave.sda_io_num = I2C_SLAVE_SDA_IO;
|
|
conf_slave.sda_pullup_en = GPIO_PULLUP_ENABLE;
|
|
conf_slave.scl_io_num = I2C_SLAVE_SCL_IO;
|
|
conf_slave.scl_pullup_en = GPIO_PULLUP_ENABLE;
|
|
conf_slave.mode = I2C_MODE_SLAVE;
|
|
conf_slave.slave.addr_10bit_en = 0;
|
|
conf_slave.slave.slave_addr = ESP_SLAVE_ADDR;
|
|
i2c_param_config(i2c_slave_port, &conf_slave);
|
|
i2c_driver_install(i2c_slave_port, conf_slave.mode, I2C_SLAVE_RX_BUF_LEN, I2C_SLAVE_TX_BUF_LEN, 0);
|
|
}
|
|
|
|
/**
|
|
* @brief test function to show buffer
|
|
*/
|
|
void disp_buf(uint8_t* buf, int len)
|
|
{
|
|
int i;
|
|
for (i = 0; i < len; i++) {
|
|
printf("%02x ", buf[i]);
|
|
if (( i + 1 ) % 16 == 0) {
|
|
printf("\n");
|
|
}
|
|
}
|
|
printf("\n");
|
|
}
|
|
|
|
void i2c_test_task(void* arg)
|
|
{
|
|
int i = 0;
|
|
int ret;
|
|
uint32_t task_idx = (uint32_t) arg;
|
|
uint8_t* data = (uint8_t*) malloc(DATA_LENGTH);
|
|
uint8_t* data_wr = (uint8_t*) malloc(DATA_LENGTH);
|
|
uint8_t* data_rd = (uint8_t*) malloc(DATA_LENGTH);
|
|
uint8_t sensor_data_h, sensor_data_l;
|
|
|
|
while (1) {
|
|
ret = i2c_master_sensor_test( I2C_MASTER_NUM, &sensor_data_h, &sensor_data_l);
|
|
xSemaphoreTake(print_mux, portMAX_DELAY);
|
|
printf("*******************\n");
|
|
printf("TASK[%d] MASTER READ SENSOR( BH1750 )\n", task_idx);
|
|
printf("*******************\n");
|
|
if (ret == ESP_OK) {
|
|
printf("data_h: %02x\n", sensor_data_h);
|
|
printf("data_l: %02x\n", sensor_data_l);
|
|
printf("sensor val: %f\n", ( sensor_data_h << 8 | sensor_data_l ) / 1.2);
|
|
} else {
|
|
printf("No ack, sensor not connected...skip...\n");
|
|
}
|
|
xSemaphoreGive(print_mux);
|
|
vTaskDelay(( DELAY_TIME_BETWEEN_ITEMS_MS * ( task_idx + 1 ) ) / portTICK_RATE_MS);
|
|
|
|
//---------------------------------------------------
|
|
for (i = 0; i < DATA_LENGTH; i++) {
|
|
data[i] = i;
|
|
}
|
|
size_t d_size = i2c_slave_write_buffer(I2C_SLAVE_NUM, data, RW_TEST_LENGTH, 1000 / portTICK_RATE_MS);
|
|
if (d_size == 0) {
|
|
printf("i2c slave tx buffer full\n");
|
|
ret = i2c_master_read_slave(I2C_MASTER_NUM, data_rd, DATA_LENGTH);
|
|
} else {
|
|
ret = i2c_master_read_slave(I2C_MASTER_NUM, data_rd, RW_TEST_LENGTH);
|
|
}
|
|
xSemaphoreTake(print_mux, portMAX_DELAY);
|
|
printf("*******************\n");
|
|
printf("TASK[%d] MASTER READ FROM SLAVE\n", task_idx);
|
|
printf("*******************\n");
|
|
printf("====TASK[%d] Slave buffer data ====\n", task_idx);
|
|
disp_buf(data, d_size);
|
|
if (ret == ESP_OK) {
|
|
printf("====TASK[%d] Master read ====\n", task_idx);
|
|
disp_buf(data_rd, d_size);
|
|
} else {
|
|
printf("Master read slave error, IO not connected...\n");
|
|
}
|
|
xSemaphoreGive(print_mux);
|
|
vTaskDelay(( DELAY_TIME_BETWEEN_ITEMS_MS * ( task_idx + 1 ) ) / portTICK_RATE_MS);
|
|
//---------------------------------------------------
|
|
int size;
|
|
for (i = 0; i < DATA_LENGTH; i++) {
|
|
data_wr[i] = i + 10;
|
|
}
|
|
//we need to fill the slave buffer so that master can read later
|
|
ret = i2c_master_write_slave( I2C_MASTER_NUM, data_wr, RW_TEST_LENGTH);
|
|
if (ret == ESP_OK) {
|
|
size = i2c_slave_read_buffer( I2C_SLAVE_NUM, data, RW_TEST_LENGTH, 1000 / portTICK_RATE_MS);
|
|
}
|
|
xSemaphoreTake(print_mux, portMAX_DELAY);
|
|
printf("*******************\n");
|
|
printf("TASK[%d] MASTER WRITE TO SLAVE\n", task_idx);
|
|
printf("*******************\n");
|
|
printf("----TASK[%d] Master write ----\n", task_idx);
|
|
disp_buf(data_wr, RW_TEST_LENGTH);
|
|
if (ret == ESP_OK) {
|
|
printf("----TASK[%d] Slave read: [%d] bytes ----\n", task_idx, size);
|
|
disp_buf(data, size);
|
|
} else {
|
|
printf("TASK[%d] Master write slave error, IO not connected....\n", task_idx);
|
|
}
|
|
xSemaphoreGive(print_mux);
|
|
vTaskDelay(( DELAY_TIME_BETWEEN_ITEMS_MS * ( task_idx + 1 ) ) / portTICK_RATE_MS);
|
|
}
|
|
}
|
|
|
|
void app_main()
|
|
{
|
|
print_mux = xSemaphoreCreateMutex();
|
|
i2c_slave_init();
|
|
i2c_master_init();
|
|
|
|
xTaskCreate(i2c_test_task, "i2c_test_task_0", 1024 * 2, (void* ) 0, 10, NULL);
|
|
xTaskCreate(i2c_test_task, "i2c_test_task_1", 1024 * 2, (void* ) 1, 10, NULL);
|
|
}
|
|
|