ESP32 Forum

Posted: **Sat Jan 28, 2023 12:39 pm**

I have ESP32-C3-DevKitC-02 interfaced with SIMA7672S 4G module over UART0,when we send AT command from the ESP module, I am getting junk response ,I have tested SIMA7672S module with arduino it works fine over there, i dont see any junk in that case.
With ESP only I am seeing junk data,Is there any setting which i am missing?

Output:
I (2468) TX_TASK: Wrote 9 bytes
I (4478) RX_TASK: Received 197 bytes:
RxData:��mm��}�W��?��_OM_}V}��_��{��M�o��_��{k��o�?��o��k��X��:��;'��=7
��jzkny��/�k��{z��o��{��{�o��o��K�ko
INCORPORATED
OK

Whereas the expected output is only INCORPORATED OK

Code: [Select all] [Expand/Collapse]

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "esp_log.h"
#include "driver/uart.h"
#include "string.h"
#include "driver/gpio.h"
 
static const int RX_BUF_SIZE = 1024;
 
#define TXD_PIN (GPIO_NUM_21)
#define RXD_PIN (GPIO_NUM_20)
#define OK      1
#define NOK     0
 
void uart_init(void)
{
    const uart_config_t uart_config = {
        .baud_rate = 115200,
        .data_bits = UART_DATA_8_BITS,
        .parity = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_1,
        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
        .source_clk = UART_SCLK_DEFAULT,
 
    };
    // We won't use a buffer for sending data.
    uart_driver_install(UART_NUM_0, RX_BUF_SIZE * 2, 0, 0, NULL, 0);
    uart_param_config(UART_NUM_0, &uart_config);
    uart_set_pin(UART_NUM_0, TXD_PIN, RXD_PIN, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
}
int sendData( const char *data)
{
    static const char *TX_TASK_TAG = "TX_TASK";
    esp_log_level_set(TX_TASK_TAG, ESP_LOG_VERBOSE);
    const int len = strlen(data);
    const int txBytes = uart_write_bytes(UART_NUM_0, data, len);
    ESP_LOGI(TX_TASK_TAG, "Wrote %d bytes", txBytes);
    return txBytes;
}
 
static uint8_t receiveData(uint8_t *data,unsigned int delay_ms)
{
    uint8_t rxBytes = 0;
    static const char *RX_TASK_TAG = "RX_TASK";
    esp_log_level_set(RX_TASK_TAG, ESP_LOG_VERBOSE);
 
    rxBytes = uart_read_bytes(UART_NUM_0, data,RX_BUF_SIZE, delay_ms / portTICK_PERIOD_MS);
    data[rxBytes]='\0';
    ESP_LOGI(RX_TASK_TAG, "Received %d bytes:\nRxData:%s\n", rxBytes,data);
    
    return rxBytes;
}
void app_main(void)
{
    uint8_t *data = (uint8_t *)malloc(RX_BUF_SIZE + 1);
    uint8_t len=0;
    static const char *MAIN_TAG = "MAIN_FUNCTION";
    esp_log_level_set(MAIN_TAG, ESP_LOG_VERBOSE);
    memset(data, 0, RX_BUF_SIZE + 1);
    uart_init();
    vTaskDelay(20);
    uart_flush(UART_NUM_0);
 
    sendData("AT\r\n");
    len = receiveData(data,2000);
    
    if(OK == check_response(data,(unsigned char*)"OK"))
    {
        ESP_LOGI(MAIN_TAG,"AT Response Received");
    }
    else
    {
        ESP_LOGI(MAIN_TAG,"AT Response Not Received");
    }
}

ESP32 Forum

ESP32-C3-DevKitC-02 Getting Junk Data over UART

ESP32-C3-DevKitC-02 Getting Junk Data over UART