DIY emergency radio build yourself
Build your own LoRa emergency radio for MeshCore. Complete guide with parts list, step-by-step plan and practical tips.
Why build your own emergency radio?
Building your own DIY emergency radio is more fun and educational than buying a ready-made device. You understand exactly how MeshCore works, can customize the device to your wishes, and save money too.
For €50-€80 you build a fully functional LoRa mesh radio device. You need no prior knowledge – this guide explains everything step by step. Ideal as a first electronics project or if you want to learn more about emergency communication.
This DIY guide has been tested by the Dutch LocalMesh community. All parts are easily available via Aliexpress or Amazon. In about 2-3 hours you have a working device.
What do you need? Parts list
Gather these parts before you start (total cost: €50-€80):
1. ESP32 LoRa board (Heltec V3)
This is the foundation: a development board with ESP32 processor and LoRa radio chip (SX1262). The Heltec V3 also has an OLED screen.
€50-€65 (Aliexpress)
2. Antenna (868 MHz)
An 868 MHz antenna for Europe. Choose a longer antenna (15-20cm) for more range. Note the connector (SMA or u.FL).
€5-€10
3. Battery (optional)
For portable use: 18650 Li-ion battery (3.7V, 2000-3000 mAh) or a small LiPo battery with JST connector.
€5-€10
4. Enclosure (optional)
Protect your device with a waterproof enclosure. You can also use a 3D-printed enclosure (files available online).
€10-€20
5. USB-C cable
For firmware installation and charging. Usually included with the Heltec board.
€3-€5 (if not included)
6. Computer (for firmware)
You need a laptop or desktop to install the MeshCore firmware via the web installer (works in Chrome browser).
(you already have)
Step by step: build your emergency radio
Step 1: Check your parts
Unpack everything and check if you have all parts. Pay special attention to: Heltec board, antenna, USB-C cable. Test if the board is undamaged.
Step 2: Connect the antenna
IMPORTANT: Connect the antenna first before applying power! Without antenna the LoRa chip can be damaged. Screw the antenna onto the SMA connector.
Step 3: Connect the board to your computer
Use the USB-C cable to connect the Heltec board to your computer. You will see a light turn on. The OLED screen may blink or be blank (normal).
Step 4: Install MeshCore firmware
Open the web installer at flasher.meshtastic.org in Chrome browser. Select your device, choose "Heltec V3", click "Install". This takes 2-5 minutes. See installation guide for details.
Step 5: Configure your device
After installation: pair your smartphone via Bluetooth, open the MeshCore app, and configure your name, region (EU 868 MHz), and channel.
Step 6: Test the range
Send a test message to other MeshCore users. Check on the network map if there are repeaters near you.
Step 7: Install battery (optional)
If you have a battery: connect it to the battery connector of the Heltec board. The device automatically charges the battery via USB.
Step 8: Place in enclosure (optional)
Mount the device in a waterproof enclosure for outdoor use. Make sure the antenna sticks out. Test afterwards if everything still works.
Practical DIY tips
💡 Tip 1: Order spare parts
Ordered antenna too short? Board doesn't work? Always order a spare antenna (€5) and possibly an extra board. This saves waiting time.
💡 Tip 2: Test without enclosure
Make sure everything works first before putting it in an enclosure. Then you can troubleshoot more easily if something goes wrong.
💡 Tip 3: Use 3D-printed enclosure
On Thingiverse and Printables you can find free 3D print files for Heltec enclosures. Cheaper than buying a waterproof case.
💡 Tip 4: Join the community
The Dutch MeshCore community on Telegram is happy to help with questions. Other makers share their experiences and tips.
💡 Tip 5: Document your build
Take photos during building. Useful for yourself (as reference) and to share with others who also want to build.
💡 Tip 6: Upgrade later
Start simple. You can always upgrade later with GPS module, solar panel, or larger battery. DIY means: always customizable.
Frequently asked questions
Do I need technical knowledge?
No, this DIY guide is suitable for beginners. You don't need to solder or program. All you do is: screw parts together and install firmware via a web interface.
How long does building take?
With all parts at hand: 2-3 hours. Most time is spent on firmware installation (5 min) and testing. If you also make an enclosure: +1 hour.
Is DIY cheaper than buying ready-made?
About the same. A ready-made Heltec V3 costs €50-€65. DIY also around that price. But you learn more and can customize the device to your wishes.
Can I also use other boards?
Yes! This guide also works for T-Beam, RAK WisBlock, or other ESP32 LoRa boards. The steps are similar, only the pinout may differ.
What if it doesn't work?
Check: Is the antenna connected? Correct firmware installed? EU 868 MHz region set? 99% of problems are caused by a loose antenna or wrong region setting.
Can I expand the device later?
Yes! You can add later: GPS module (for location sharing), solar panel (for charging), larger battery (longer runtime), or even sensors (temperature, humidity).
Build your own emergency radio
With this guide you build your own LoRa emergency radio for MeshCore in a few hours. More fun than buying, you learn how it works, and you have a unique device that fits your needs exactly.