In today's world, smart homes are no longer a luxury — they’re a DIY reality. Whether it's turning lights on from your phone or checking room temperature while you're away, automation has never been more accessible.
And with the Raspberry Pi Pico 2 W, building smart home devices is easier than ever. In this tutorial, we’ll walk you through creating a Bluetooth-enabled home sensor using this compact yet powerful microcontroller.
Let’s get started!
Why Use Raspberry Pi Pico 2 W for Smart Home Projects?
The Raspberry Pi Pico 2 W is the latest upgrade in the Pico lineup. What makes it stand out?
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Built-in Bluetooth 5.2 and Wi-Fi
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Low power consumption – ideal for always-on smart sensors
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Dual-core Arm Cortex-M0+ processor
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Affordable and beginner-friendly
This board is perfect for home automation projects that need wireless communication, and today, we'll focus on using Bluetooth 5.2.
What Are We Building?
We’re going to build a basic smart temperature and humidity sensor that communicates with your smartphone via Bluetooth. You’ll be able to read real-time room data using a mobile app.
Core Functions:
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Collect room temperature & humidity
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Transmit data over Bluetooth
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View live data on your smartphone
What You’ll Need:
Before diving in, let’s gather the components.
Hardware:
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Raspberry Pi Pico 2 W
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DHT11 or DHT22 Temperature & Humidity Sensor
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Breadboard & jumper wires
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USB cable (for programming the Pico)
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A smartphone with a Bluetooth terminal app (e.g. Serial Bluetooth Terminal for Android)
Software:
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Thonny IDE (Python environment)
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MicroPython firmware for Pico
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Bluetooth library (ubluetooth)
Step 1: Setting Up the Raspberry Pi Pico 2 W
1. Download & install Thonny IDE on your computer: https://thonny.org
2. Flash MicroPython firmware on Pico 2 W:
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Connect the Pico while holding the BOOTSEL button.
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It will appear as a storage device.
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Download the latest MicroPython UF2 file from: https://micropython.org/download/rp2-pico-w
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Drag the file into the Pico drive. It will reboot with MicroPython ready.
Step 2: Connect the DHT Sensor to Pico
Wire as follows:
|
DHT Pin |
Connects To |
|
VCC |
3.3V (Pico) |
|
GND |
GND (Pico) |
|
DATA |
GP15 |
Use jumper wires and a breadboard to make the setup neat.
Step 3: Writing the Code
Here’s a simple Python script to:
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Read temperature & humidity
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Send data over Bluetooth
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import machine import time import dht import bluetooth from machine import Pin from bluetooth import BLE sensor = dht.DHT22(Pin(15)) ble = bluetooth.BLE() ble.active(True) def send_data(data): if ble.is_connected(): ble.gatts_notify(0, 0, data) def advertise(): ble.gap_advertise(100, b'\x02\x01\x06\x03\x03\xE0\xFF') def on_connect(bt): print("Bluetooth connected") while True: sensor.measure() temp = sensor.temperature() hum = sensor.humidity() data = f"Temp: {temp}°C | Hum: {hum}%" print(data) send_data(data.encode()) time.sleep(5) advertise() ble.irq(handler=lambda e: on_connect(ble)) |
Note: You may need to adjust for BLE GATT setup based on your device. You can use external libraries for more advanced features like notifications or pairing.
Step 4: Test With a Bluetooth App
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Download Serial Bluetooth Terminal (Android) or a similar app for iOS.
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Turn on Bluetooth and scan for your Pico device.
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Once connected, you’ll start seeing real-time data in the app.
Step 5: Improve the Build (Optional)
Here are some ways to expand your smart sensor:
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Add an OLED display to show readings on the device itself
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Power your project using a battery + charging module (like TP4056)
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Integrate multiple sensors (like motion or light sensors)
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Send data to cloud via Wi-Fi (using MQTT)
Troubleshooting Tips
Pico not showing up?
Check your USB cable. Some are power-only, not data-capable.
Can’t connect Bluetooth?
Ensure your mobile Bluetooth supports BLE (Bluetooth Low Energy).
Sensor returns 0 values?
Double-check wiring and make sure the sensor has time to stabilize.
Why Bluetooth 5.2?
The Raspberry Pi Pico 2 W comes with Bluetooth 5.2, which offers:
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Lower power consumption (great for battery-powered devices)
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Improved data rate and range
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Compatibility with most new smartphones and IoT devices
Unlike Wi-Fi, Bluetooth is ideal when you need close-range communication without the complexity of internet connectivity.
Final Thoughts
Building a smart sensor with Raspberry Pi Pico 2 W and Bluetooth is a rewarding first step into home automation. It's affordable, beginner-friendly, and highly customizable.
This project introduces you to:
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Using MicroPython for IoT
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Communicating over Bluetooth 5.2
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Reading data from sensors in real-time
With just a few components and some code, you’ve created your very own smart home sensor.
Ready To Build More?
You can use the same foundation to create:
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Smart door/window alerts
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Motion detectors
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Air quality monitors
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Light automation systems
The world of DIY home automation is yours to explore!