M5stack Unit C6l for Meshtastic

The M5Stack C6L: Off-Grid Comms and Sensor Networking

Mesh networking keeps getting easier and cheaper, and the M5Stack C6L is a solid example of where things are headed. It's built around an ESP32-C6 and a Semtech SX1262 LoRa radio, operating in the 868-923 MHz ISM bands. Transmit power goes up to +22 dBm, receive sensitivity down to -147 dBm. It comes with Meshtastic already loaded, so setup is just flashing your config and joining the mesh. No cell towers, no subscriptions, no internet needed. For around $23, you get a complete node that can talk to other Meshtastic devices kilometers away depending on terrain and antenna setup. The whole point of LoRa is long range, low power communication, and the C6L delivers on both fronts.

Functionality!

M5Stack packed a lot into this thing. There's a small 0.66" OLED (SSD1306) for status info, an RGB LED, a buzzer, and a button for basic interaction. Two separate SMA antenna ports keep the 2.4 GHz Wi-Fi and LoRa signals from stepping on each other - one port for each, no compromises. They also added over-voltage protection with an AW32901FCR, which is a nice touch for field deployments where power can be unpredictable. Sleep current is under 700 microamps on Grove power, so running this off a battery or small solar setup is completely doable. At 62mm x 24mm x 8mm (not counting antennas), it's small enough to fit into most enclosures without much planning. The included antennas are decent too - 84mm for Wi-Fi and 108mm for LoRa, both with 3dBi gain and SMA connectors. You can always swap in larger antennas later if you need more range.

Extensibility

The Grove port (HY2.0-4P) gives you I2C, UART, or GPIO depending on how you configure it, which means you can plug in pretty much any sensor M5Stack makes. The LEGO-compatible holes help when you're trying to mount it in a project box or prototype rig. The ESP32-C6 also supports Wi-Fi 6, Bluetooth 5, and Zigbee, though for Meshtastic the LoRa range is really the point. Having those other radios available opens up some interesting possibilities for hybrid projects down the line - maybe a node that bridges Meshtastic to your home network, or one that talks to Zigbee sensors locally and relays data over the mesh.

A fun example using environmental sensors

I tested the C6L by putting together a weather station with a CoreS3 and an ENV III sensor for temperature, humidity, and pressure using PamirAI's Distiller. The CoreS3 handles the display and sensor readings, the C6L handles mesh communication. Send a message with "weather" on the test channel and it responds with the current temp, humidity, and atmospheric pressure. Simple request-response, no app needed, just Meshtastic doing its thing.

If you're looking to get into Meshtastic or want a compact node for sensor projects, the C6L is worth checking out. M5Stack has more info on their site at https://m5stack.com and you can find the C6L product page at https://shop.m5stack.com/products/m5stack-c6l-unit-for-meshtastic-sx1262-esp32-c6 - though as of writing it's showing out of stock, so keep an eye on it.