esp control leds

esp control leds

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Write a complete guide which includes equipment, wiring connections and programs for the following.

there are two esp32 i will call esp32-1 and esp32-2

on esp32-1 there are eight on off switches

on esp32-2 there are eight leds

the switches on esp32-1 remotely turn the leds on esp32-2 on and off

the esp communicate using es pnow

### Complete Guide for Remote Control of LEDs Using ESP32 and ESP-NOW

This guide provides step-by-step instructions to set up a system where ESP32-1 (with eight switches) remotely controls the LEDs on ESP32-2 using ESP-NOW for communication.

#### **Equipment Required**

1. **Two ESP32 development boards**
2. **Eight push-button switches**
3. **Eight LEDs**
4. **Eight 220Ω resistors (for LEDs)**
5. **Breadboards and jumper wires**
6. **USB cables for programming ESP32 boards**
7. **A computer with Arduino IDE installed**

#### **Wiring Connections**

**ESP32-1 (Switches)**

| Switch | GPIO Pin |
| —— | ——– |
| S1 | GPIO 12 |
| S2 | GPIO 13 |
| S3 | GPIO 14 |
| S4 | GPIO 27 |
| S5 | GPIO 26 |
| S6 | GPIO 25 |
| S7 | GPIO 33 |
| S8 | GPIO 32 |

* Connect one side of each switch to the corresponding GPIO pin as shown in the table.
* Connect the other side of each switch to the ground (GND).

**ESP32-2 (LEDs)**

| LED | GPIO Pin |
| — | ——– |
| L1 | GPIO 16 |
| L2 | GPIO 17 |
| L3 | GPIO 18 |
| L4 | GPIO 19 |
| L5 | GPIO 21 |
| L6 | GPIO 22 |
| L7 | GPIO 23 |
| L8 | GPIO 5 |

* Connect the anode (long leg) of each LED to the corresponding GPIO pin as shown in the table.
* Connect the cathode (short leg) of each LED to one end of a 220Ω resistor.
* Connect the other end of each resistor to the ground (GND).

#### **Programming the ESP32 Boards**

**ESP32-1 Code (Switches)**

“`cpp
#include <esp_now.h>
#include <WiFi.h>

// Structure to hold the button states
typedef struct struct_message {
int buttonStates[8];
} struct_message;

struct_message myData;

// Array of switch pins
const int switchPins[8] = {12, 13, 14, 27, 26, 25, 33, 32};

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

// Initialize the switch pins as input
for (int i = 0; i < 8; i++) {
pinMode(switchPins[i], INPUT_PULLUP);
}

// Initialize WiFi in station mode
WiFi.mode(WIFI_STA);

// Init ESP-NOW
if (esp_now_init() != ESP_OK) {
Serial.println(“Error initializing ESP-NOW”);
return;
}

// Set the peer address
esp_now_peer_info_t peerInfo;
memcpy(peerInfo.peer_addr, broadcastAddress, 6);
peerInfo.channel = 0;
peerInfo.encrypt = false;

// Add peer
if (esp_now_add_peer(&peerInfo) != ESP_OK) {
Serial.println(“Failed to add peer”);
return;
}
}

void loop() {
// Read the switch states
for (int i = 0; i < 8; i++) {
myData.buttonStates[i] = digitalRead(switchPins[i]);
}

// Send the switch states to ESP32-2
esp_err_t result = esp_now_send(broadcastAddress, (uint8_t *) &myData, sizeof(myData));

if (result == ESP_OK) {
Serial.println(“Sent successfully”);
} else {
Serial.println(“Error sending the data”);
}

delay(100); // Send data every 100ms
}
“`

**ESP32-2 Code (LEDs)**

“`cpp
#include <esp_now.h>
#include <WiFi.h>

// Structure to hold the received button states
typedef struct struct_message {
int buttonStates[8];
} struct_message;

struct_message myData;

// Array of LED pins
const int ledPins[8] = {16, 17, 18, 19, 21, 22, 23, 5};

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

// Initialize the LED pins as output
for (int i = 0; i < 8; i++) {
pinMode(ledPins[i], OUTPUT);
}

// Initialize WiFi in station mode
WiFi.mode(WIFI_STA);

// Init ESP-NOW
if (esp_now_init() != ESP_OK) {
Serial.println(“Error initializing ESP-NOW”);
return;
}

// Register receive callback
esp_now_register_recv_cb(onDataRecv);
}

void loop() {
// Nothing to do here
}

// Callback function that will be executed when data is received
void onDataRecv(const uint8_t * mac, const uint8_t *incomingData, int len) {
memcpy(&myData, incomingData, sizeof(myData));

// Set the LED states based on the received button states
for (int i = 0; i < 8; i++) {
digitalWrite(ledPins[i], myData.buttonStates[i]);
}
}
“`

#### **Explanation**

1. **Initialization:**

* Both ESP32 boards are initialized in station mode (`WiFi.mode(WIFI_STA)`).
* ESP-NOW is initialized (`esp_now_init()`).

2. **ESP32-1 (Switches):**

* The GPIO pins are set up as inputs with pull-up resistors.
* The button states are read and stored in a structure.
* The structure is sent to ESP32-2 using `esp_now_send()`.

3. **ESP32-2 (LEDs):**

* The GPIO pins are set up as outputs.
* A callback function (`onDataRecv`) is registered to handle received data.
* When data is received, the LED states are updated based on the received button states.

#### **Running the System**

1. **Upload the ESP32-1 code** to the first ESP32 board.
2. **Upload the ESP32-2 code** to the second ESP32 board.
3. **Open the Serial Monitor** in the Arduino IDE for both boards to monitor the status.
4. **Press the switches** on ESP32-1 and observe the LEDs on ESP32-2 turning on and off accordingly.

This setup uses ESP-NOW for efficient and low-latency communication between the two ESP32 boards, making it ideal for real-time control applications like this one.