Answers checklist.

[X] I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
[X] I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
[X] I have searched the issue tracker for a similar issue and not found a similar issue.

IDF version.

v5.2.0

Espressif SoC revision.

ESP32-D0WD-V3 (revision 3)

Operating System used.

Windows

How did you build your project?

VS Code IDE

If you are using Windows, please specify command line type.

None

Development Kit.

ESP32 Dev Kit V1

Power Supply used.

USB

What is the expected behavior?

I would like to send a variable via serial at the highest possible speed and in different packages.

What is the actual behavior?

When I send it via serial every 1 second the variable goes in a different package (I'm using a converter to read it with my device using the Geshe DB Genius)

Using Geshe DB Genius read 1000ms:

If I send it every 5 ms, the variable goes in the same package: Using Geshe DB Genius read 5ms:

I tried using "uart wait_tx_done" but it still worked the same.

Steps to reproduce.

/* UART Echo Example

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

include "freertos/FreeRTOS.h"

include "freertos/task.h"

include "driver/uart.h"

include "driver/gpio.h"

include "sdkconfig.h"

include "esp_log.h"

include "string.h"

static void echo_task(void *arg) { const uart_port_t uart_num = UART_NUM_2; 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, .rx_flow_ctrl_thresh = UART_SCLK_APB, }; // Configure UART parameters ESP_ERROR_CHECK(uart_param_config(uart_num, &uart_config));

ESP_ERROR_CHECK(uart_set_pin(UART_NUM_2, 17, 16, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE));

const int uart_buffer_size = (1024 * 2);
QueueHandle_t uart_queue;
// Install UART driver using an event queue here
ESP_ERROR_CHECK(uart_driver_install(UART_NUM_2, uart_buffer_size, \
                                    uart_buffer_size, 10, &uart_queue, 0));

 // Write data to UART.
char* test_str = "This is a test string.\n\r";

while (1) {

    uart_write_bytes(uart_num, (const char*)test_str, strlen(test_str));
    vTaskDelay(pdMS_TO_TICKS(5));

}

}

void app_main(void) { xTaskCreate(echo_task, "uart_echo_task", CONFIG_EXAMPLE_TASK_STACK_SIZE, NULL, 10, NULL); }

Debug Logs.

No response

More Information.