SENSORS/ACTUATORS

INTERNET OF THING (IoT)

Arduino UNO Q - Telegram Bot

Arduino UNO Q - OpenClaw

Arduino UNO Q - Potentiometer

A potentiometer (also called a rotary angle sensor or variable resistor) lets you manually adjust a value by turning a knob. Common uses include controlling volume, brightness, and motor speed. In this tutorial, you will learn how to connect a potentiometer to Arduino UNO Q, read its ADC value, convert it to voltage, and check readings remotely via Telegram.

※ NOTE THAT:

Arduino UNO Q ADC difference: The STM32 MCU on Arduino UNO Q has a 12-bit ADC (values 0–4095), compared to the 10-bit ADC (0–1023) on many other Arduino boards. The reference voltage is 3.3V. Always use these values when converting ADC readings.

Hardware Preparation

1	×	Arduino UNO Q
1	×	USB Cable for Arduino Uno Q
1	×	Potentiometer
1	×	Alternatively, 10k Ohm Trimmer Potentiometer
1	×	Alternatively, Potentiometer Kit
1	×	Alternatively, Potentiometer Module with Knob
1	×	Breadboard
1	×	Jumper Wires
1	×	Recommended: Screw Terminal Block Shield for Arduino Uno
1	×	Recommended: Sensors/Servo Expansion Shield for Arduino Uno
1	×	Recommended: Breadboard Shield for Arduino Uno
1	×	Recommended: Enclosure for Arduino Uno
1	×	Recommended: Prototyping Base Plate & Breadboard Kit for Arduino UNO

Or you can buy the following kits:

DIYables Sensor Kit (18 sensors/displays)

Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you.
Additionally, some of these links are for products from our own brand, DIYables .

Overview of Potentiometer

Pinout

A potentiometer has three pins:

GND pin: connect to GND
VCC pin: connect to 3.3V (on Arduino UNO Q, the MCU operates at 3.3V)
Output pin: connect to an analog input pin on the Arduino UNO Q

※ NOTE THAT:

The GND and VCC pins can be swapped — this reverses the direction of the output.

How It Works

Rotating the knob changes the resistance between the output pin and GND/VCC, which changes the output voltage proportionally:

At 0° (GND side): output = 0V
At maximum angle (VCC side): output = 3.3V (on Arduino UNO Q)
In between: output = (angle / ANGLE_MAX) × 3.3V

Arduino UNO Q ADC

The Arduino UNO Q MCU (STM32U585) reads the output voltage through a 12-bit ADC — producing values from 0 to 4095:

Source	Range
Knob angle rotated	0° to ANGLE_MAX
Output voltage	0V to 3.3V
ADC value read by Arduino UNO Q	0 to 4095
Mapped output value	VALUE_MIN to VALUE_MAX

Common Conversions

ADC to voltage:

voltage = floatMap(adc_value, 0, 4095, 0, 3.3);

ADC to a controllable level (e.g. brightness 0–255):

brightness = map(adc_value, 0, 4095, 0, 255);

ADC to angle (if ANGLE_MAX is known):

angle = map(adc_value, 0, 4095, 0, ANGLE_MAX);

※ NOTE THAT:

map() returns an integer. For floating-point conversions, use floatMap() as shown in the code below.

Wiring Diagram

This image is created using Fritzing. Click to enlarge image

MCU Code — Potentiometer

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.

/* * 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-potentiometer */ float floatMap(float x, float in_min, float in_max, float out_min, float out_max) { return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min; } void setup() { // nothing to set up } void loop() { // Read ADC value from pin A0 (12-bit: 0-4095 on Arduino UNO Q) int adc_value = analogRead(A0); // Convert ADC value to voltage (3.3V reference on Arduino UNO Q) float voltage = floatMap(adc_value, 0, 4095, 0, 3.3); // TO DO: use adc_value or voltage in your logic here // Example: map to a 0-100 scale // int level = map(adc_value, 0, 4095, 0, 100); delay(500); }

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.
Wire the potentiometer: Connect GND to GND, VCC to 3.3V, and the output pin to A0 according to the wiring diagram.
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.

Create New App in Arduino App Lab on Arduino UNO Q

Give the App a name, for example: DIYables_Potentiometer
Click Create to confirm.
You will see a set of folders and files generated inside your new App.

Arduino App Lab App folders and files on Arduino UNO Q

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.

Add sketch library in Arduino App Lab on Arduino UNO Q

Search for Arduino_RouterBridge created by Arduino and click the Install button.

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Upload: Click the Run button in Arduino App Lab to compile and upload to the STM32.

Click Run button in Arduino App Lab on Arduino UNO Q

Turn the potentiometer knob — the ADC value and voltage are read every 500 ms. Results are visible via the Bridge Monitor in the next section.
Pro Tip: Replace the TO DO comment with map(adc_value, 0, 4095, 0, 255) to drive LED brightness via PWM.

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 potentiometer is connected to the MCU (STM32) — wired to an analog input pin (A0) on the STM32. The MCU reads ADC values and converts them to voltage.
The MPU cannot read the potentiometer directly — it must request the reading from the MCU via Bridge.call(). The MCU responds with the current ADC value and voltage.
The MPU has Wi-Fi — because the MPU runs full Debian Linux with Wi-Fi, it can report the potentiometer reading via Telegram on demand.
Communication: Bridge.call() on the Linux side invokes Bridge.provide() functions on the MCU side
⚠️ Reserved: /dev/ttyHS1 (Linux) and Serial1 (MCU) are used by the Arduino Router — never open them directly

In short: MPU requests potentiometer reading → MCU reads ADC → MCU reports value and voltage → MPU logs or forwards it.

MCU sketch — potentiometer 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-potentiometer */ #include "Arduino_RouterBridge.h" float floatMap(float x, float in_min, float in_max, float out_min, float out_max) { return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min; } void get_potentiometer() { int adc_value = analogRead(A0); float voltage = floatMap(adc_value, 0, 4095, 0, 3.3); Monitor.print("ADC: "); Monitor.print(adc_value); Monitor.print(", Voltage: "); Monitor.println(voltage); } void setup() { Bridge.begin(); Monitor.begin(); Bridge.provide("get_potentiometer", get_potentiometer); Monitor.println("Potentiometer Bridge ready"); } void loop() {}

Python script (Arduino App Lab) — poll potentiometer from Linux:

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 above into sketch/sketch.ino, install the Arduino_RouterBridge library, 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 — the Python side polls the potentiometer every second.
Turn the potentiometer knob and watch the ADC value and voltage update in real time.
Check the console: Open the Console tab → MCU Monitor subtab.

App Lab Console Output

sketch.ino

1#include "Arduino_RouterBridge.h"

Serial Monitor

Python

Message (Enter to send a message to "Newbiely" on usb(2820070321))

Potentiometer Bridge ready ADC: 0, Voltage: 0.00 ADC: 820, Voltage: 0.66 ADC: 2048, Voltage: 1.65 ADC: 3275, Voltage: 2.64 ADC: 4095, Voltage: 3.30

Telegram Integration

Read the current potentiometer value 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 potentiometer reading:

""" This Arduino UNO Q script was developed by newbiely.com This Arduino UNO Q script 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-potentiometer """ 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 == "/read": reading = Bridge.call("get_potentiometer") send_message(chat_id, reading) else: send_message(chat_id, "Commands:\n/read — read potentiometer ADC value and voltage") time.sleep(1) App.run(user_loop=loop)

Note: Replace YOUR_BOT_TOKEN with the token obtained from @BotFather on Telegram.
Send /read to trigger a potentiometer reading — the result appears in the MCU Monitor.

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: Turn the potentiometer, send /read — the bot replies with the ADC value and voltage.

App Lab Console Output

sketch.ino

1#include "Arduino_RouterBridge.h"

Serial Monitor

Python

[2026-04-29 12:00:01] Telegram: /read [2026-04-29 12:00:01] ADC: 1234, Voltage: 1.00 [2026-04-29 12:03:20] Telegram: /read [2026-04-29 12:03:20] ADC: 3072, Voltage: 2.48

ArduinoBot

bot

Today

/read

10:15 AM ✓✓

ADC: 1234, Voltage: 1.00

10:16 AM

OpenClaw Integration

You can adapt the OpenClaw to this tutorial by refering the instruction on Arduino Uno Q - OpenClaw Tutorial

Application/Project Ideas

Remote volume knob: Use a potentiometer to set audio volume — read the level remotely via Telegram
Light level setter: Use a potentiometer to set an LED brightness target — check the set level via Telegram
Motor speed selector: Map potentiometer value to motor speed — confirm speed via Telegram
Threshold configurator: Use the potentiometer to set a sensor threshold (e.g. temperature alarm) remotely verifiable
Calibration tool: Use the potentiometer to trim a sensor offset — check the calibration value via Telegram

Challenge Yourself

Easy: Add a second output: map the ADC to a 0–100% level and print it alongside voltage
Medium: Expose the potentiometer value as a percentage (0–100) via a get_level() Bridge callback
Advanced: Build a Telegram bot that continuously monitors the potentiometer and sends a notification when the value changes by more than 10% from the last reading

Function References

Learn More

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