Meshtastic Example

This example builds a minimal Meshtastic-compatible node on either the LilyGo T-Deck or the M5Stack Cardputer-Adv (with the LoRa+GPS Cap), selectable via menuconfig. It brings up the board’s SX1262 radio through the BSP, applies the LongFast modem configuration for the selected region, listens for Meshtastic traffic, periodically broadcasts its node info and a text ping, and prints received text messages, node info, and positions.

Point a stock Meshtastic device (set to the same region and the default LongFast channel) at it and the two should see each other: your espp node will appear in the device’s node list, and text messages will flow both ways. This has been confirmed on real hardware (Cardputer-Adv running this example exchanging messages with a T-Deck on stock Meshtastic firmware, US LongFast).

How to use example

Hardware Required

  • LilyGo T-Deck / T-Deck Plus, or M5Stack Cardputer-Adv with the LoRa+GPS Cap (U201 / U214)

  • Ideally a second Meshtastic device (or another espp node) to talk to

Configure

Run idf.py menuconfig and set, under Example Configuration:

  • Hardware - your board

  • LoRa region - this MUST match the other Meshtastic devices and be legal where you are

  • Optionally the node name and ping intervals

⚠️ Always attach the antenna before transmitting, and make sure the region you select is legal for you.

Build and Flash

Run idf.py -p PORT flash monitor to build, flash and monitor the project.

(To exit the serial monitor, type Ctrl-].)

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Troubleshooting: “I don’t see the other node / no messages”

  • Set the region on every device. A Meshtastic node with an unset region does not transmit or receive at all - this is by far the most common cause of a silent node. On a stock device set the region in the app or CLI; in this example set LoRa region in menuconfig. Both sides must use the same region.

  • Match the channel. This example uses the default public LongFast channel (default PSK). The stock device must be on the same modem preset (LongFast) and the default channel; a custom channel name or PSK changes the channel hash and the two will not decode each other.

  • Check the serial log. On boot the example prints the computed frequency and channel hash, e.g. ... @ 906.875 MHz (hash 0x08) for US LongFast. If the frequency or hash differs from what you expect, your region or channel does not match the other device.

  • Attach the antenna. Transmitting without one can damage the radio and will severely limit range.