I am using my EPS32S3 to communicate with a MCP23017-E/SO via I2C. My code is shown below, and this is what I see on my logic analyzerlogic analyzer. The data doesnt make sense. I would expect to at least see it transmit the device address correctly (which is 0x20).
The datasheet says the address should be 0x20 if I am shorting A0,A1, and A2 to ground. This is how my circuit is connected.
What should I change below? Thanks.
Code: Select all
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "driver/spi_master.h"
#include "driver/gpio.h"
#include "driver/uart.h"
#include "driver/i2c_master.h"
#include "driver/i2c.h"
#include "esp_log.h"
#include "esp_adc_cal.h"
#include "driver/adc.h"
#include "hal/i2c_types.h"
#include "soc/i2c_periph.h"
#include "hal/i2c_hal.h"
#define PIN_NUM_SCL 1
#define PIN_NUM_SDA 2
#define I2C_MASTER_NUM I2C_NUM_0
#define MCP23017_ADDR 0x20
#define GPIOB 0x13
#define I2C_CMD_SIZE_MAX 256
esp_err_t i2c_init(void){
esp_err_t ret;
i2c_master_bus_config_t bus_config = {
.i2c_port = I2C_MASTER_NUM,
.sda_io_num = PIN_NUM_SDA,
.scl_io_num = PIN_NUM_SCL,
.clk_source = I2C_CLK_SRC_DEFAULT,
.glitch_ignore_cnt = 7,
.flags.enable_internal_pullup = false
};
i2c_master_bus_handle_t i2c_bus_handle;
ret = i2c_new_master_bus(&bus_config, &i2c_bus_handle );
ESP_LOGI("I2C", "i2c_new_master_bus returned %s", esp_err_to_name(ret));
if(ret!= ESP_OK)
return -1;
i2c_device_config_t dev_config_MCP23017= {
.dev_addr_length = I2C_ADDR_BIT_LEN_7,
.device_address = MCP23017_ADDR,
.scl_speed_hz = I2C_MASTER_FREQ_HZ
};
ret = i2c_master_bus_add_device(i2c_bus_handle, &dev_config_MCP23017, &i2c_MCP23017_handle);
ESP_LOGI("I2C", "i2c_master_bus_add_device %s", esp_err_to_name(ret));
if(ret!= ESP_OK)
return -1;
return ESP_OK;
}
esp_err_t i2c_register_write(i2c_master_dev_handle_t dev_handle, uint8_t reg_addr, uint8_t *data, size_t len)
{
esp_err_t ret;
ESP_LOGI("I2C", "Transmitting to device");
uint8_t buffer[I2C_CMD_SIZE_MAX];
memcpy(buffer, ®_addr, len);
memcpy(buffer+1, data, len);
ret = i2c_master_transmit(dev_handle, buffer, len+1, portMAX_DELAY);
ESP_LOGI("I2C", "i2c_register_write %s", esp_err_to_name(ret));
return ret;
}
void app_main() {
if(i2c_init() == -1){
ESP_LOGI("I2C", "i2c_init failed");
}
while(1){
ESP_LOGI("I2C", "Writing to GPIOB");
vTaskDelay(1000);
uint8_t data = 0xFF;
i2c_register_write(i2c_MCP23017_handle, GPIOB, &data, 1);
vTaskDelay(pdMS_TO_TICKS(2000));
}
}