Configuration

After flashing, the ATM needs to be paired with a funding source — an LNbits wallet with the FOSSA extension. This is what lets the device generate valid LNURL-withdraw codes completely offline (see Introduction).

1. Create the LNbits FOSSA connection

Create an LNbits wallet. Add the FOSSA extension and create a new ATM connection in the extension by clicking NEW FOSSA.

Creating a new FOSSA connection in LNbits

Creating a new FOSSA connection in the LNbits extension.

2. Enter the connection string on the device

Copy the FOSSA connection string. The ATM stores its configuration in flash memory; on first boot it starts a WiFi access point where you enter that string.

  • Connect to the LightningATM WiFi network.

  • Open http://atm.local in your browser.

  • Paste the FOSSA connection string and save.

The WiFi configuration portal

The on-device WiFi configuration portal.

Tip

To reconfigure the ATM later, hold the BOOT button (GPIO 0) on the ESP32 during power-on. The device will re-enter the WiFi configuration portal. The BOOT button is on the ESP32 board inside the enclosure and is not accessible to end users.

Optional: BlockClock idle display

The firmware can show Bitcoin network data (block height, price, fees, difficulty, mempool stats) on the e-paper display while the ATM is idle — the “BlockClock” mode, fetched in the background from mempool.space. This requires a WiFi network with internet access and is configured in the same portal. It is purely a display feature and does not affect offline withdrawals.