Hi everyone,
I’m using an ESP32 and L298N to control a DC motor, and I’ve set up a web interface to adjust the motor speed. Here's my hardware setup:
- ESP32
- L298N
- Power: 6 AA batteries in series
- Motor connected to the L298N
Problem:
When I connect the ENA pin of the L298N to GPIO 19 on the ESP32 for PWM speed control, the motor doesn’t run at all. However:
- If I remove the ENA connection and use the jumper cap to short ENA on the L298N, the motor runs fine (but speed cannot be controlled).
- If I connect ENA directly to the ESP32’s 5V power output, the motor runs (but speed still cannot be controlled).
Questions:
- Is this a hardware wiring issue or is there a limitation with the L298N’s ENA pin?
- Is my PWM setup correct in the code?
- Is there a better way to control the motor speed using the ESP32 and L298N?
Here’s my schematics:
Note: Battery are all AA Battery
Here’s my code:
#include <WiFi.h>
#include <WebServer.h>
#define IN1 5
#define IN2 18
#define ENA 19
const char* ssid = "xxxx";
const char* password = "xxxx";
WebServer server(80);
int speed = 128;
void setup() {
Serial.begin(115200);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi...");
}
Serial.println("Connected to WiFi");
Serial.print("ESP32 IP Address: ");
Serial.println(WiFi.localIP());
pinMode(IN1, OUTPUT);
pinMode(IN2, OUTPUT);
pinMode(ENA, OUTPUT);
ledcAttach(ENA, 30000, 8);
server.on("/", HTTP_GET, handleRoot);
server.on("/forward", HTTP_GET, handleForward);
server.on("/backward", HTTP_GET, handleBackward);
server.on("/stop", HTTP_GET, handleStop);
server.on("/speed", HTTP_GET, handleSpeed);
server.begin();
}
void loop() {
server.handleClient();
}
void handleRoot() {
String html = "<html><body>";
html += "<h1>Control Motor</h1>";
html += "<button onclick=\"location.href='/forward'\">Forward</button><br><br>";
html += "<button onclick=\"location.href='/backward'\">Backward</button><br><br>";
html += "<button onclick=\"location.href='/stop'\">Stop</button><br><br>";
html += "<form action='/speed' method='get'>Set Speed (0-255): ";
html += "<input type='number' name='value' min='0' max='255'>";
html += "<input type='submit' value='Set Speed'></form><br>";
html += "</body></html>";
server.send(200, "text/html", html);
}
void handleForward() {
digitalWrite(IN1, HIGH);
digitalWrite(IN2, LOW);
ledcWrite(0, speed);
String html = "<html><body><h1>Motor Moving Forward</h1><a href='/'>Back</a></body></html>";
server.send(200, "text/html", html);
}
void handleBackward() {
digitalWrite(IN1, LOW);
digitalWrite(IN2, HIGH);
ledcWrite(0, speed);
String html = "<html><body><h1>Motor Moving Backward</h1><a href='/'>Back</a></body></html>";
server.send(200, "text/html", html);
}
void handleStop() {
ledcWrite(0, 0);
digitalWrite(IN1, LOW);
digitalWrite(IN2, LOW);
String html = "<html><body><h1>Motor Stopped</h1><a href='/'>Back</a></body></html>";
server.send(200, "text/html", html);
}
void handleSpeed() {
if (server.hasArg("value")) {
int newSpeed = server.arg("value").toInt();
if (newSpeed >= 0 && newSpeed <= 255) {
speed = newSpeed;
String html = "<html><body><h1>Speed Set to " + String(speed) + "</h1><a href='/'>Back</a></body></html>";
server.send(200, "text/html", html);
} else {
server.send(400, "text/plain", "Invalid speed value! Must be between 0 and 255.");
}
} else {
server.send(400, "text/plain", "Speed value missing!");
}
}