RAKwireless Aims at Easier, More Reliable Raspberry Pi Meshtastic Nodes with Its New HAT Add-On
The WisMesh Pi HAT RAK6421 acts as a carrier for WisBlock LoRa transceivers, as well as optional GNNS receivers and sensors.
Internet of Things (IoT) specialist RAKwireless has announced a gadget that aims to make it easier to build and deploy Meshtastic LoRa-based mesh radio nodes powered by the Raspberry Pi family of single-board computers: the WisMesh Pi HAT RAK6421.
"If you have ever tried running a Raspberry Pi Meshtastic setup for more than a few days, especially in an always-on role, you have probably noticed something doesn't quite hold up," the company claims of the problem it set out to solve with its new Hardware Attached on Top (HAT) accessory. "The issue is rarely the software. More often, it is the hardware stack holding everything together. A Raspberry Pi Meshtastic node is only as reliable as the way its radio, sensors, and interfaces are connected."
The WisMesh Pi HAT RAK6521, brought to our attention by CNX Software, delivers a more reliable connection, RAKwireless claims, in part by avoiding using the USB connections in favor of being mounted to the Raspberry Pi itself and communicating over the 40-pin general-purpose input/output (GPIO) header. Perhaps unusually, it doesn't actually include a radio of its own; rather, it's a carrier board for WisBlock radio modules, allowing the builder to pick the module that's right for a given use-case.
The accessory is designed for use with the Raspberry Pi 4 Model B and Raspberry Pi 5 full-size single-board computers, though should also work with Raspberry Pi Compute Module 5 devices in appropriate 40-pin-capable carrier boards if you get creative about how it mounts. It's designed for use with meshtasticd, a daemon that handles communication over LoRa to other nodes in the community-driven Meshtastic mesh network. The HAT can also act as an interface to an optional Global Navigation Satellite System (GNSS) receiver for positioning, as well as add-on sensors including carbon dioxide, ambient and UV light, temperature, humidity, and pressure.
"Firmware-based [Meshtastic] devices are typically portable," RAKwireless claims of the usual microcontroller-powered nodes. "They are designed for mobility, low power consumption, and simplicity. They do their job well, but they are not meant to host complex services or act as permanent network anchors. A Raspberry Pi running meshtasticd plays a very different role. It becomes a Raspberry Pi LoRa gateway, a relay, or even a backbone node. It can bridge data into MQTT, feed dashboards, log activity, and support automation workflows. It is no longer just participating in the mesh; it is helping define a scalable mesh networking hardware environment."
The WisMesh Pi HAT RAK6421 is now available on the RAKwireless store, at $14; suitable LoRa transceivers start at $11 for the Semtech SX1262-based WisBlock RAK13300.