Arduino UNO Q - DC Motor Shield
The Motor Shield Rev3 plugs directly onto the Arduino UNO Q headers — same pin layout as the classic Uno. In this guide you will:
- Stack the Motor Shield Rev3 onto an Arduino UNO Q board.
- Wire a DC motor and an external power supply.
- Write code that spins the motor forward and backward.
- Adjust motor speed through PWM values (0–255).
- Apply and release the electronic brake.
- Operate two motors at once using Channel A and Channel B.
Hardware Preparation
Or you can buy the following kits:
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
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Additionally, some of these links are for products from our own brand, DIYables .
Motor Shield Rev3 Overview
At the heart of the Motor Shield Rev3 sits the L298P dual full-bridge driver. This chip gives you independent control over two DC motors — each with its own direction line, PWM speed line, brake line, and current-sensing analog input.
Here is what each control line does:
- Direction — a digital output that sets the spin direction. Writing HIGH spins one way; LOW spins the other.
- PWM — an analog (PWM) output that sets the duty cycle. Values range from 0 (stopped) to 255 (full speed).
- Brake — a digital output. Setting it HIGH locks the motor shaft; setting it LOW lets the motor spin freely.
- Current Sensing — an analog input that reports how much current the motor is drawing.
Because the Arduino UNO Q keeps the same header positions as the classic Uno, every pin lines up automatically:
| Function | Channel A | Channel B |
|---|---|---|
| Direction | D12 | D13 |
| PWM (Speed) | D3 | D11 |
| Brake | D9 | D8 |
| Current Sensing | A0 | A1 |
Powering the Motors
Motors need more current than USB can provide. Connect a 6–12 V external supply to the shield's power screw terminals. The Arduino UNO Q itself continues running from USB.
Wiring Diagram
Place the Motor Shield Rev3 onto the Arduino UNO Q headers, making sure every pin seats properly. Attach the DC motor leads to the Channel A screw terminals. Hook up the external power supply to the power screw terminals.
This image is created using Fritzing. Click to enlarge image
Single Motor on Channel A
MCU Code
The Arduino UNO Q has two processors: the STM32 MCU (handles real-time hardware control) and the Qualcomm MPU (runs Debian Linux). In this section, only the STM32 MCU is programmed — the Linux side stays idle. A later section will show how both processors work together.
The code below alternates the motor direction every 2 seconds with braking in between:
/*
* This Arduino UNO Q code was developed by newbiely.com
*
* This Arduino UNO Q code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-uno-q/arduino-uno-q-dc-motor-shield
*/
#include <DIYables_DC_Motor.h>
DIYables_DC_Motor motor(MOTOR_CH_A);
bool directionState = false;
void setup() {
motor.begin();
}
void loop() {
directionState = !directionState;
int direction = directionState ? MOTOR_FORWARD : MOTOR_BACKWARD;
motor.run(direction, 30);
delay(2000);
motor.brake();
delay(2000);
}
Detailed Instructions
- First time with Arduino UNO Q? Follow the Getting Started with Arduino UNO Q tutorial to get your development environment ready before proceeding.
- Stack the shield: Firmly press the Motor Shield Rev3 onto the Arduino UNO Q headers.
- Wire the motor: Connect your DC motor to the Channel A screw terminals.
- Connect power: Attach the external power supply to the shield's power terminals.
- Connect: Plug the Arduino UNO Q into your computer with a USB-C cable.
- Open Arduino App Lab: Launch Arduino App Lab and wait until it detects your Arduino UNO Q.
- Create a new App: Click the Create New App button.
- Give the App a name, for example: DIYables_DCMotorShield
- Click Create to confirm.
- You will see a set of folders and files generated inside your new App.
- Find the sketch/sketch.ino file — this is where you will paste the MCU sketch.
Paste the sketch: Copy the MCU code above and paste it into the sketch file. Keep other files as default.
- Install the library: Click the Add sketch library button (the open book icon with a + sign) in the left sidebar.
- Search for DIYables_DC_Motor created by DIYables.io and click the Install button.
Bricks
No bricks added...
Sketch Libraries
No sketch libra...
Files
python
sketch
.gitignore
README.md
app.yaml
sketch.ino
- Search for Arduino_RouterBridge created by Arduino and click the Install button.
Bricks
No bricks added...
Sketch Libraries
No sketch libra...
Files
python
sketch
.gitignore
README.md
app.yaml
sketch.ino
- Upload: Click the Run button in Arduino App Lab to compile and upload to the STM32.
- Observe: The motor alternates between forward and backward every 2 seconds, braking for 2 seconds between each direction change.
Method Quick Reference
| Method | What It Does | Usage |
|---|---|---|
| run(dir, speed) | Spins the motor in the given direction at the given speed | motor.run(MOTOR_FORWARD, 100) |
| setSpeed(speed) | Changes speed without touching direction or brake | motor.setSpeed(200) |
| setDirection(dir) | Changes direction without touching speed or brake | motor.setDirection(MOTOR_BACKWARD) |
| brake() | Engages the brake and drops speed to zero | motor.brake() |
| release() | Disengages the brake | motor.release() |
| readCurrent() | Returns raw ADC from the current-sensing pin | motor.readCurrent() |
Single Motor on Channel B
Identical behavior to Channel A, but on Channel B — just swap the channel constant.
/*
* This Arduino UNO Q code was developed by newbiely.com
*
* This Arduino UNO Q code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-uno-q/arduino-uno-q-dc-motor-shield
*/
#include <DIYables_DC_Motor.h>
DIYables_DC_Motor motor(MOTOR_CH_B);
bool directionState = false;
void setup() {
motor.begin();
}
void loop() {
directionState = !directionState;
int direction = directionState ? MOTOR_FORWARD : MOTOR_BACKWARD;
motor.run(direction, 30);
delay(2000);
motor.brake();
delay(2000);
}
Detailed Instructions
- Wire the motor to the Channel B screw terminals.
- Follow the same Quick Steps as the Channel A section above (create App, paste sketch, install libraries, upload).
- The motor alternates direction and brakes the same way — only the underlying pins differ.
Two Motors — Both Channels
Drive two motors independently: both forward, both backward, and opposite directions.
/*
* This Arduino UNO Q code was developed by newbiely.com
*
* This Arduino UNO Q code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-uno-q/arduino-uno-q-dc-motor-shield
*/
#include <DIYables_DC_Motor.h>
DIYables_DC_Motor motorA(MOTOR_CH_A);
DIYables_DC_Motor motorB(MOTOR_CH_B);
void setup() {
motorA.begin();
motorB.begin();
}
void loop() {
// Both motors forward
motorA.run(MOTOR_FORWARD, 100);
motorB.run(MOTOR_FORWARD, 100);
delay(2000);
// Brake both
motorA.brake();
motorB.brake();
delay(1000);
// Both motors backward
motorA.run(MOTOR_BACKWARD, 100);
motorB.run(MOTOR_BACKWARD, 100);
delay(2000);
// Brake both
motorA.brake();
motorB.brake();
delay(1000);
// Opposite directions
motorA.run(MOTOR_FORWARD, 100);
motorB.run(MOTOR_BACKWARD, 100);
delay(2000);
// Brake both
motorA.brake();
motorB.brake();
delay(1000);
}
Detailed Instructions
- Attach one motor to Channel A and another to Channel B screw terminals.
- Follow the same Quick Steps as the Channel A section above (create App, paste sketch, install libraries, upload).
- The sketch cycles through both-forward, both-backward, and opposite-direction patterns.
Linux + MCU Bridge Programming
The Arduino UNO Q has two processors that work together: the MPU (Qualcomm, runs Debian Linux) and the MCU (STM32, runs Zephyr OS with your Arduino sketch). They communicate using RPC via the Arduino_RouterBridge library — never via raw serial ports.
- The Motor Shield is connected to the MCU (STM32) — direction, PWM, and brake pins are all on the Arduino UNO Q header, driven by the STM32.
- The MPU cannot control the motor shield directly — it must call a function on the MCU via Bridge.call() to spin forward, backward, or brake.
- The MPU has Wi-Fi — because the MPU runs full Debian Linux with Wi-Fi, it can receive Telegram commands and remotely control the motor.
- Communication: Bridge.call() on the Linux side invokes Bridge.provide_safe() functions on the MCU side (since motor.run() and motor.brake() use hardware APIs)
- ⚠️ Reserved: /dev/ttyHS1 (Linux) and Serial1 (MCU) are used by the Arduino Router — never open them directly
In short: MPU sends command → MCU drives Motor Shield → Motor Shield controls DC motor.
MCU sketch — Motor Shield control with Bridge and Monitor output:
/*
* This Arduino UNO Q code was developed by newbiely.com
*
* This Arduino UNO Q code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-uno-q/arduino-uno-q-dc-motor-shield
*/
#include "Arduino_RouterBridge.h"
#include <DIYables_DC_Motor.h>
DIYables_DC_Motor motor(MOTOR_CH_A);
void motor_forward() {
motor.run(MOTOR_FORWARD, 200);
Monitor.println("Motor: Forward");
}
void motor_backward() {
motor.run(MOTOR_BACKWARD, 200);
Monitor.println("Motor: Backward");
}
void motor_brake() {
motor.brake();
Monitor.println("Motor: Brake");
}
void setup() {
Bridge.begin();
Monitor.begin();
motor.begin();
motor.brake();
Bridge.provide_safe("forward", motor_forward);
Bridge.provide_safe("backward", motor_backward);
Bridge.provide_safe("brake", motor_brake);
Monitor.println("DC Motor Shield Bridge ready");
}
void loop() {}
Python script (Arduino App Lab) — control motor from Linux:
/*
* This Arduino UNO Q code was developed by newbiely.com
*
* This Arduino UNO Q code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-uno-q/arduino-uno-q-dc-motor-shield
*/
from arduino.app_utils import *
import time
def loop():
print("Motor spinning forward")
Bridge.call("forward")
time.sleep(3)
print("Motor braking")
Bridge.call("brake")
time.sleep(1)
print("Motor spinning backward")
Bridge.call("backward")
time.sleep(3)
print("Motor braking")
Bridge.call("brake")
time.sleep(1)
App.run(user_loop=loop)
- Note: Make sure Bridge.begin() is called in the MCU sketch and the sketch is uploaded before running the Python script on the Linux side.
- ⚠️ Warning: Never directly open /dev/ttyHS1 (on Linux) or use Serial1 (on MCU) in your code — these are reserved by the Arduino Router and accessing them will break the Bridge.
Detailed Instructions
- Upload the MCU sketch: Open Arduino App Lab, create a new App, paste the Bridge MCU sketch into sketch/sketch.ino, install both DIYables_DC_Motor and Arduino_RouterBridge libraries, and click Run.
- Add the Python script: Paste the Python code above into the Python tab of the same App.
- Run the App: Click Run — Python cycles the motor forward, brake, backward, brake automatically.
- Check the console: Open the Console tab → MCU Monitor subtab to see motor status messages.
App Lab Console Output
sketch.ino
1#include "Arduino_RouterBridge.h"
Serial Monitor
Python
DC Motor Shield Bridge ready
Motor: Forward
Motor: Brake
Motor: Backward
Motor: Brake
Telegram Integration
Control the DC motor remotely from anywhere via Telegram.
If you do not have a Telegram bot yet, see How to Create a Telegram Bot to get your bot token before continuing.
MCU sketch: Keep the same MCU sketch from the previous Bridge section — no changes needed. Make sure it is already uploaded and running on the STM32 before proceeding.
Python script (Arduino App Lab) — Telegram bot for motor shield control:
/*
* This Arduino UNO Q code was developed by newbiely.com
*
* This Arduino UNO Q code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-uno-q/arduino-uno-q-dc-motor-shield
*/
from arduino.app_utils import *
import requests
import time
BOT_TOKEN = "YOUR_BOT_TOKEN"
API_URL = f"https://api.telegram.org/bot{BOT_TOKEN}"
last_update_id = 0
def send_message(chat_id, text):
requests.post(f"{API_URL}/sendMessage", json={"chat_id": chat_id, "text": text})
def get_updates():
global last_update_id
resp = requests.get(f"{API_URL}/getUpdates", params={"offset": last_update_id + 1, "timeout": 5})
return resp.json().get("result", [])
def loop():
global last_update_id
updates = get_updates()
for update in updates:
last_update_id = update["update_id"]
msg = update.get("message", {})
chat_id = msg.get("chat", {}).get("id")
text = msg.get("text", "").strip()
if text == "/forward":
Bridge.call("forward")
send_message(chat_id, "Motor spinning forward.")
elif text == "/backward":
Bridge.call("backward")
send_message(chat_id, "Motor spinning backward.")
elif text == "/brake":
Bridge.call("brake")
send_message(chat_id, "Motor braking.")
else:
send_message(chat_id, "Commands:\n/forward — spin motor forward\n/backward — spin motor backward\n/brake — brake motor")
time.sleep(1)
App.run(user_loop=loop)
- Note: Replace YOUR_BOT_TOKEN with the token obtained from @BotFather on Telegram.
- Send /forward to spin the motor forward.
- Send /backward to spin the motor backward.
- Send /brake to brake the motor.
Detailed Instructions
- Upload the MCU sketch: Use the Bridge MCU sketch from the previous section (upload it first if not already done).
- Paste the Telegram script: Copy the Python code above into the Python tab of your App in Arduino App Lab.
- Set your token: Replace YOUR_BOT_TOKEN in the script with your actual bot token.
- Run the App: Click Run — the bot starts listening for Telegram messages.
- Test it: Send /forward — the motor spins. Send /brake — it stops hard. Send /backward — it reverses.
App Lab Console Output
sketch.ino
1#include "Arduino_RouterBridge.h"
Serial Monitor
Python
[2026-04-29 12:00:01] Telegram: /forward
[2026-04-29 12:00:01] Motor spinning forward.
[2026-04-29 12:02:10] Telegram: /backward
[2026-04-29 12:02:10] Motor spinning backward.
[2026-04-29 12:04:05] Telegram: /brake
[2026-04-29 12:04:05] Motor braking.
Telegram
12:45
Welcome to Telegram!
ArduinoBot
10:19
Chatting with Arduino...
BotFather
Yesterday
Your bot has been created.
ArduinoBot
bot
OpenClaw Integration
OpenClaw integration for Arduino UNO Q DC motor shield control is coming soon.
- Coming Soon: OpenClaw support for controlling DC motors via the Motor Shield on Arduino UNO Q will be covered in a future update.
Application/Project Ideas
- Remote robot drive: Use Channel A and Channel B together to build a two-motor differential-drive robot controlled via Telegram
- Automated conveyor: Drive a Channel A motor forward or backward on schedule using the MPU's Linux cron
- Motorized camera slider: Use precise PWM speed control to move a camera smoothly along a track
- Dual-axis turntable: Control two motors simultaneously for pan and tilt motion via Telegram commands
- Smart fan controller: Adjust fan speed remotely — set slow, medium, or full speed from Telegram
Challenge Yourself
- Easy: Add a /status Telegram command that reports the current motor state (forward, backward, or braking)
- Medium: Add a /speed <0-255> Telegram command to set the PWM speed before spinning
- Advanced: Control both Channel A and Channel B independently from Telegram using commands like /a forward, /b backward, /a brake