McApp is a web application designed for convenient work with the MeshCom node. It runs on Raspberry Pi and provides an interface accessible from modern web browsers. Raspberry Pi acts as a lightweight server and mediator for communication between the MeshCom device and the web client. McApp supports node connection via Bluetooth Low Energy (BLE) and UDP.
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What is McApp and what is it for
The purpose of McApp is not to replace MeshCom, but to create a practical user interface for its daily operation. In the browser, functions for chat, map of received positional reports, MHeard, and configuration are available. The interface is designed as a responsive web application, so it can be used on a computer, tablet, or phone. It also supports adding the application to the home screen as a PWA.
Why Raspberry Pi?
Raspberry Pi Zero 2 W is particularly suitable for this task due to its low hardware requirements. The project specifies support for Raspberry Pi Zero 2 W and other devices with ARM Cortex-A53. The required system is Raspberry Pi OS Lite 64-bit based on Debian Bookworm or Trixie, with documentation stating 512 MB RAM and an SD card with a capacity of at least 8 GB. A desktop environment on Pi Zero is not needed.
Pi can be placed directly at the MeshCom node. The user then accesses McApp over the network from a computer or mobile device. This creates a separation between the radio part and the user interface without the need to connect a computer directly to the MeshCom device.
How is McApp technically built
The McApp frontend is a web application built on TypeScript and Vue.js. The backend uses Python and FastAPI. Communication between the browser and the backend uses REST API and SSE (Server-Sent Events). In front of the backend is lighttpd, which provides a web interface and mediates requests to FastAPI. Application settings are stored in an SQLite database.
In BLE communication, a separate BLE service is used that communicates with the MeshCom node via Bluetooth GATT. In UDP communication, McApp can work with the MeshCom node via UDP port 1799. The project also mentions the possibility of connecting multiple nodes via UDP.
Chat - main function of McApp
The chat interface is designed similarly to modern communication applications. It supports personal and group messages, filtering by calling sign or group, and delivery confirmation. Messages are first stored in a sending queue to prevent overwhelming the MeshCom node. The currently set delay between sent messages is 12 seconds, while the documentation warns that even this interval may not always be sufficient for reliable RF operation.
MeshCom network map
The map displays received POS reports from MeshCom nodes. Individual stations can be searched for, and upon selecting a node, additional information can be displayed. McApp also supports satellite view and dark mode. For nodes with telemetry, it can display, for example, temperature, humidity, and atmospheric pressure.
MHeard - a useful tool for radio amateurs
For the technically oriented radio amateur, the MHeard feature is interesting. McApp displays heard stations along with RSSI and SNR data and can also show the relay path, i.e., the route by which the station reached the monitored node. After selecting a station, its route can be highlighted on the map. This allows monitoring not only the network activity but also the quality of individual radio connections and the relays used.
BLE versus UDP
BLE is particularly interesting for local connections between Raspberry Pi and MeshCom nodes. The documentation favors it also because it allows obtaining more information, including RSSI and SNR. McApp uses keep-alive for BLE and attempts to automatically restore communication upon connection loss. UDP is suitable where the MeshCom node is accessible via an IP network.
Updates and remote access
Installation, updating, and repairing McApp are handled using a bootstrap script. The project also supports updating directly from the web interface. The OTA mechanism uses three deployment slots, checks the functionality of the new version, and automatically rolls back to the previous version in case of failure.
For remote access, HTTPS can optionally be set up using Caddy and Let’s Encrypt certificates. The documentation mentions support for DuckDNS, Cloudflare, deSEC.io, and Cloudflare Tunnel services. Therefore, remote access is not a necessary part of the local installation but is an available optional feature.
Security and message validation
McApp checks incoming data for UTF-8 and APRS compatibility. It filters out characters that can be safely removed. Messages containing problematic binary data are rejected. This mechanism is designed to prevent corrupted data from a MeshCom node from causing issues in the user interface or during further processing.
Who is McApp meant for?
McApp makes the most sense for a radio amateur who is already using MeshCom and wants to have a convenient web interface accessible from multiple devices. It is particularly interesting for operation with Raspberry Pi, network monitoring using MHeard and maps, evaluating RSSI and SNR, or for experimenting with multiple MeshCom nodes over UDP. The project remains an extension over the existing MeshCom system, not a replacement for it.
Vilo, it might need articles about Meshcom first, and then about McApp. According to the Meshcom maps https://mcmap.oevsv.at/ máme v čase keď to píšem v OM 0,00 Meshcom uzlov, teda rovnako ako v HA. Sieť je rozšírená hlavne v OE, DL, I v pásme 433MHz ako HAM sieť.
We have a network with a similar name but with completely different parameters Meshcore, in the 'free' band 868MHz connecting almost all of Slovakia. https://mesh.om3kff.sk/
Amateurs here have devices for Meshcom, mainly like Lora APRS, or from experiments with the Meshtastic network in 433M, so there's a chance that some devices will 'burn' to Meshcom if there is awareness 😉