ESP32 getting hot when using ESPNOW

Other Hardware 3rd Party Boards
1

Hello, I am using an ESP32 with ESPNOW and it is getting warm to the touch. Is this heat okay for the ESP32 over a long period of time? Here is my code:

ESP32 #1 Code:

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

uint8_t addressESP2[] = {0xEC, 0x94, 0xCB, 0x4C, 0x76, 0x18};

typedef struct TxStruct
{
    int touchOut;
} TxStruct;
TxStruct sentData;

void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status)
{
    Serial.print("\r\nLast Packet Send Status:\t");
    Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
}

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

    WiFi.mode(WIFI_STA);

    if (esp_now_init() != ESP_OK)
    {
        Serial.println("Error initializing ESP-NOW");
        return;
    }

    esp_now_register_send_cb(OnDataSent);
  
    esp_now_peer_info_t peerInfo;
    memcpy(peerInfo.peer_addr, addressB2, 6);
    peerInfo.channel = 0;  
    peerInfo.encrypt = false;
  
    if(esp_now_add_peer(&peerInfo) != ESP_OK)
    {
        Serial.println("Failed to add peer");
        return;
    }


}

void loop()
{
    int result;
    int touchP = touchRead(15);
    if(touchP < 80) { result = 1; }
    else { result = 0; }
    esp_now_send(addressB2, (uint8_t *) &result, sizeof(result));
    delay(25);
}

ESP32 #2 Code:

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

uint8_t addressESP1[] = {0xEC, 0x94, 0xCB, 0x4C, 0xB2, 0xF0};

typedef struct RxStruct
{
    int touchIn;
} RxStruct;
RxStruct receivedData;

void OnDataRecv(const uint8_t * mac, const uint8_t *incomingData, int len)
{
    memcpy(&receivedData, incomingData, sizeof(receivedData));
}

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

    WiFi.mode(WIFI_STA);

    if (esp_now_init() != ESP_OK)
    {
        Serial.println("Error initializing ESP-NOW");
        return;
    }

    esp_now_register_recv_cb(OnDataRecv);
  
    esp_now_peer_info_t peerInfo;
    memcpy(peerInfo.peer_addr, addressB1, 6);
    peerInfo.channel = 0;  
    peerInfo.encrypt = false;
  
    if(esp_now_add_peer(&peerInfo) != ESP_OK)
    {
        Serial.println("Failed to add peer");
        return;
    }

    pinMode(2, OUTPUT);
}

void loop()
{
    if(receivedData.touchIn == 1) { Serial.println("Touched"); digitalWrite(2, HIGH); }
    else { Serial.println("Not Touched"); digitalWrite(2, LOW); }
}

These ESP32's are going to be controlling some LEDs. One ESP32 will be the remote and the other will control the LEDs. The remote ESP32 I can put into deep-sleep and wake up with its touch pins, but the other ESP32 that is controlling the leds can't be put into deep-sleep because it is controlling the leds, it also needs to always be ready to receive data from the remote ESP32. Thanks.

2

Getting warm makes your wiring suspect, not your code.

3

There is not wiring. You must mean the PCB design. I'm using the built-in LED and am using the built-in touch pins. I've had it plugged in for about an hour, and it still feels just 'warm'. Do you think it is bad for it to be warm for a long period of time, like days?

4

Unfortunately "warm" is relative. Is it warmer than your skin?
I've not worked with this exact board but it might be trying to send continuous radio data/signals.

I would load the example "blink without delay" onto the board and see if it is still the same.

5

@JohnRob,

No.

I did that, and no it does not get hot at all. I think your right, it's trying to continuously send radio data/signals.