Esp now reduce jitter

[salman2135]

Hi everyone,

I am working on a low jitter solution using two ESP32 S3 V1 board with Arduino IDE. My delay and jitter is currently 8 ms and 4 ms respectively. I am wondering how to improve the performace of in terms of jitter. Any clue would be greatly appreciated!

Below is my code:

Sender Code:

Code: Select all

#include <WiFi.h>
#include <esp_now.h>
#include <esp_wifi.h>
#include <esp_pm.h>
#include <esp_wifi_types.h>

#define REF_PIN 35

uint8_t receiverMacList[][6] = {
  { 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF }, // dummy
  { 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF  } // dummy
};

uint8_t dataToSend = 0;             // Variable to hold the integer to send
int receivedData = 0;           // Variable to store the data received from the receiver
bool dataReceivedFlag = false;  // Flag to check if data is received

// Callback function for send status
void onDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
  Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Success" : "Fail");
}

// Callback function for receiving data
void onDataReceive(const esp_now_recv_info_t *recv_info, const uint8_t *incomingData, int len) {
}

void setup() {
  Serial.begin(115200);

  // Initialize Wi-Fi in Station Mode
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();

  // Set Long Range Mode
  esp_wifi_set_protocol(WIFI_IF_STA, WIFI_PROTOCOL_LR);

  // Fix Wi-Fi Channel for Low Jitter
  esp_wifi_set_channel(1, WIFI_SECOND_CHAN_NONE);

  // Set Max Transmission Power
  esp_wifi_set_max_tx_power(78);  // Max TX power (19.5 dBm)
  esp_wifi_set_ps(WIFI_PS_NONE);

  // Initialize ESP-NOW
  if (esp_now_init() != ESP_OK) {
    Serial.println("ESP-NOW initialization failed");
    return;
  }

  // Register the send and receive callback functions
  esp_now_register_send_cb(onDataSent);
  esp_now_register_recv_cb(onDataReceive);

  // Add each MAC address as a peer
  for (int i = 0; i < sizeof(receiverMacList) / sizeof(receiverMacList[0]); i++) {
    esp_now_peer_info_t peerInfo = {};
    memcpy(peerInfo.peer_addr, receiverMacList[i], 6);
    peerInfo.channel = 0;  // Use the default channel
    peerInfo.encrypt = false;
    if (esp_now_add_peer(&peerInfo) != ESP_OK) {
      Serial.printf("Failed to add peer: %02X:%02X:%02X:%02X:%02X:%02X\n",
                    receiverMacList[i][0], receiverMacList[i][1], receiverMacList[i][2],
                    receiverMacList[i][3], receiverMacList[i][4], receiverMacList[i][5]);
    }
  }

  Serial.println("ESP-NOW Sender Ready. Enter a number to send:");
}

void loop() {
  // Check if data is available on the serial port
  if (Serial.available() == 1) {
    // Read integer from the serial port
    dataToSend = Serial.read();
    // NULL means send to all peers
    for (int i = 0; i < sizeof(receiverMacList) / sizeof(receiverMacList[0]); i++) {
      esp_err_t result = esp_now_send(receiverMacList[i], (uint8_t *)&dataToSend, sizeof(dataToSend));
      if (result == ESP_OK) {
        Serial.printf("Data sent to %02X:%02X:%02X:%02X:%02X:%02X\n",
                      receiverMacList[i][0], receiverMacList[i][1], receiverMacList[i][2],
                      receiverMacList[i][3], receiverMacList[i][4], receiverMacList[i][5]);
      } else {
        Serial.println("Unknown error");
      }
    }
  }
}

Receiver code

Code: Select all

#include <WiFi.h>
#include <esp_now.h>
#include <esp_wifi.h>

// Queue for received messages
QueueHandle_t espNowQueue;

uint8_t eight_bit_value = 0;                                       // Variable to hold received integer
uint8_t senderMAC[] = { 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB };  // Replace with the sender's MAC address
#define TX_PIN 17                                              // Define TX pin for UART1
#define RX_PIN 16                                              // Define RX pin for UART1
#define BAUD_RATE 115200                                       // Set baud rate


// Callback function for receiving data
void onDataReceive(const esp_now_recv_info_t *recv_info, const uint8_t *incomingData, int len) {
  eight_bit_value = incomingData[0];
  BaseType_t xHigherPriorityTaskWoken = pdFALSE;
  xQueueSendFromISR(espNowQueue, &eight_bit_value, &xHigherPriorityTaskWoken);
  portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
}

void espNowTask(void *param) {

  int message;

  while (true) {
    if (xQueueReceive(espNowQueue, &message, portMAX_DELAY)) {
      // Log the received message
      uint8_t cmd[] = {
        (uint8_t)0xAB
        (uint8_t)0xBB
      };
      Serial1.write(cmd, sizeof(cmd));
    }
  }
}

void setup() {

  Serial.begin(115200);
  Serial1.begin(BAUD_RATE, SERIAL_8N1, RX_PIN, TX_PIN);

  // Set the ESP32 to station mode
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  // Set Long Range Mode
  esp_wifi_set_protocol(WIFI_IF_STA, WIFI_PROTOCOL_LR);
  esp_wifi_set_ps(WIFI_PS_NONE);
  // Fix Wi-Fi Channel
  esp_wifi_set_channel(1, WIFI_SECOND_CHAN_NONE);

  // Initialize ESP-NOW
  if (esp_now_init() != ESP_OK) {
    Serial.println("ESP-NOW initialization failed");
    return;
  }

  // Register the receive callback function
  esp_now_register_recv_cb(onDataReceive);

  // Create Queue for Received Messages
  espNowQueue = xQueueCreate(10, sizeof(int));
  if (espNowQueue == NULL) {
    Serial.println("Failed to create queue");
    return;
  }

  // Create Processing Task
  xTaskCreate(espNowTask, "ESPNow Task", 4096, NULL, 2, NULL);
}

void loop() {
}

Any clue/help would be really appreciated!!

[MicroController]

viewtopic.php?f=18&t=43258#p141196