Overview
The motor_l298n node drives DC motors using the L298N dual H-bridge motor driver
module. It provides independent speed control via PWM on the enable pin and direction control via the IN1/IN2 logic
pins. Supports forward, reverse, coast (stop), and active braking modes for precise motor management in robotics,
conveyor systems, and automated vehicles.
Properties
| Property | Type | Required | Default | Description |
|---|---|---|---|---|
| enablePin | number | Yes | 12 | PWM enable pin (ENA or ENB on L298N) |
| in1Pin | number | Yes | 23 | Direction control pin IN1 |
| in2Pin | number | Yes | 24 | Direction control pin IN2 |
| pwmFrequency | number | No | 1000 | PWM frequency in Hz for speed control |
| invertDirection | boolean | No | false | Swap forward/reverse direction mapping |
| initialSpeed | number | No | 0 | Initial speed on deploy (0-100%) |
Inputs
Object with speed and direction controls.
{
"speed": 75,
"direction": "forward"
}speed 0-100 (percentage) direction "forward" | "reverse" | "stop" | "brake" Outputs
Outputs current motor state with pin assignments.
{
"speed": 75,
"direction": "forward",
"enablePin": 12,
"in1": 1,
"in2": 0,
"timestamp": 1709251200000
}Direction Logic Truth Table
| Direction | ENA (PWM) | IN1 | IN2 | Result |
|---|---|---|---|---|
| forward | Speed % | HIGH | LOW | Motor spins clockwise |
| reverse | Speed % | LOW | HIGH | Motor spins counter-clockwise |
| stop | 0 | LOW | LOW | Motor coasts to stop (free spin) |
| brake | 100% | HIGH | HIGH | Active braking (rapid stop) |
Wiring / Connection Diagram
L298N Motor Driver to Raspberry Pi
Raspberry Pi L298N Module
+-----------+ +----------------+
| | | |
| GPIO 12 |---[PWM]--------| ENA | DC Motor A
| GPIO 23 |---[Digital]----| IN1 OUT1|------(+)
| GPIO 24 |---[Digital]----| IN2 OUT2|------(-)
| | | |
| GND |---[Ground]-----| GND | DC Motor B
| | | OUT3|------(+)
+-----------+ | ENB OUT4|------(-)
| IN3 |
External Power | IN4 |
+--------+ | |
| 6-12V |---[+]------------| +12V |
| Supply |---[-]------------| GND |
+--------+ +----------------+
Note: Remove 5V jumper if motor supply > 12V
Keep jumper for onboard 5V regulatorImportant: Always use an external power supply for the motor. Never power DC motors directly from the Raspberry Pi. Connect all grounds together.
Example Use Cases
Dashboard Motor Control
Use a slider for speed and buttons for direction from a dashboard.
[
{
"id": "speed-slider",
"type": "slider",
"label": "Motor Speed",
"min": 0,
"max": 100
},
{
"id": "merge-controls",
"type": "function",
"func": "var speed = flow.get('speed') || 0;
var dir = flow.get('direction') || 'stop';
msg.payload = { speed: speed, direction: dir };
return msg;"
},
{
"id": "motor-a",
"type": "motor_l298n",
"enablePin": 12,
"in1Pin": 23,
"in2Pin": 24,
"pwmFrequency": 1000
}
]Conveyor Belt with Sensor Stop
Run a conveyor belt and stop when an object is detected at the end.
[
{
"id": "start-conveyor",
"type": "inject",
"payload": { "speed": 60, "direction": "forward" }
},
{
"id": "end-sensor",
"type": "pir",
"pin": 25
},
{
"id": "stop-motor",
"type": "change",
"rules": [
{ "t": "set", "p": "payload", "to": { "speed": 0, "direction": "brake" } }
]
},
{
"id": "belt-motor",
"type": "motor_l298n",
"enablePin": 12,
"in1Pin": 23,
"in2Pin": 24
}
]MQTT Remote Vehicle Control
Control a two-motor vehicle remotely via MQTT commands.
[
{
"id": "mqtt-control",
"type": "mqtt-in",
"topic": "vehicle/drive"
},
{
"id": "left-motor",
"type": "motor_l298n",
"enablePin": 12,
"in1Pin": 23,
"in2Pin": 24,
"pwmFrequency": 1000
},
{
"id": "right-motor",
"type": "motor_l298n",
"enablePin": 13,
"in1Pin": 5,
"in2Pin": 6,
"pwmFrequency": 1000,
"invertDirection": true
}
]Common Use Cases
Robotics
Wheeled robots and differential drive vehicles
Conveyor Systems
Industrial belt and roller conveyor control
Pump Control
Variable-speed water and fluid pump systems
CNC Machines
Spindle motors and axis drive control