Development Preview

Set it up.

Flash MeshCore firmware and join the Chicago Offline network. About five minutes, no coding required.

⚠️ You'll need a Chrome or Edge browser. The web flasher uses WebSerial, which only works in Chromium-based browsers. Firefox and Safari won't work for the flashing step.
Step 1

Flash MeshCore firmware

1

Open the MeshCore Web Flasher

Go to flasher.meshcore.io in Chrome or Edge.

2

Connect your device via USB

Plug your LoRa device into your computer with a USB cable. Most devices use USB-C.

3

Select your device and flash

The flasher will detect your device. Select it from the list and choose "Companion" as the firmware type — that's what you want for a phone-paired messenger node.

Click Flash and wait about 30 seconds. Done.

💡 Already have MeshCore firmware? If you bought a pre-flashed device (like the RAK WisMesh Pocket), skip this step entirely. Go straight to Step 2.
Step 2

Get the MeshCore app

Download the free companion app for your phone or computer. This is how you'll send and receive messages.

The official app is by Liam Cottle. There's also MeshCore Open, a free open-source alternative that works on all platforms.

Step 3

Pair and connect

1

Turn on Bluetooth

Make sure Bluetooth is enabled on your phone.

2

Open the app and scan

The app will scan for nearby MeshCore devices. Your device should appear in the list — tap it to pair.

3

You're on the network

Once paired, you'll start seeing other nodes on the Chicago Offline mesh. Your device automatically discovers nearby nodes and relays messages through the network.

Try sending a message to the #public channel — if anyone's in range, they'll see it.

💡 Range depends on location. In Chicago, line-of-sight between rooftop antennas can reach 5+ miles. Street-level is more like 0.5-2 miles depending on buildings. The mesh fills in the gaps — your message hops through repeaters to reach further.
Optional

Improve your range

The stock antenna works, but a better antenna makes a big difference. If you want to reach more of the network:

Upgrade your antenna

Replace the stock stubby antenna with a tuned whip antenna. The Muzi Works 17cm Whip (~$12) is a great upgrade — 98% transmission efficiency (SWR 1.3) vs the stock stubby at 69% (SWR 3.5). SMA male connector, fits most boards directly.

Get it up high

LoRa loves altitude. A device in a window works okay. A device on a roof works great. Even moving from a first-floor desk to a third-floor window can make a noticeable difference.

Run a repeater

Got an extra device? Flash it as a Repeater instead of Companion and put it somewhere high. You'll extend the network for everyone. Solar-powered repeaters are a popular build — a $30 board + small solar panel = permanent infrastructure.

Troubleshooting

Common issues

The web flasher doesn't see my device

Make sure you're using Chrome or Edge (not Firefox/Safari). Try a different USB cable — some cables are charge-only and don't carry data. For Heltec V3, try holding the BOOT button while plugging in.

The app doesn't find my device via Bluetooth

Make sure Bluetooth is on and location permissions are granted (Android requires this for BLE scanning). Try power-cycling the device. If you just flashed it, give it a few seconds to boot up.

I can't see any other nodes

This is normal if there are no other MeshCore devices in range. Chicago Offline coverage is growing but not everywhere yet. Check the Network Scope to see where active nodes are. Try different locations — even moving to a window can help.

My device shows "No contacts" or no channels

It takes a moment for the device to discover the mesh. Walk around, wait a few minutes, or try sending a broadcast to #public. Repeaters in range will relay your message even if you don't see them as contacts yet.

Which firmware type should I pick?

Companion = pairs with your phone for messaging (most people). Repeater = relays messages, no phone needed (put it somewhere high). Room Server = hosts chat rooms for the mesh (advanced).

That's it. You're on the mesh.

← Back to Chicago Offline