Articles
How MeshTRX works inside, why it was built this way, and what it cost.
How to turn a Meshtastic board into a radio: Heltec V3 and V4
Step by step: flash a Heltec V3 or V4 from the browser, connect a phone over Bluetooth and talk by voice with no internet or cell service. What to buy, how not to burn the board, and what to do if it ran Meshtastic before.
Read →Heltec V3, V4 or V4.3: which board to pick for voice
How the Heltec WiFi LoRa 32 revisions differ, how to tell yours from the marking on the board, why V4 has an external amplifier, 868 versus 433 MHz, and which antennas and batteries people in our group use.
Read →Communication without internet or cell service: PMR radios, Meshtastic, MeshCore and MeshTRX
Ways to stay in touch where there is no cell service: hiking, at a country house, during an outage. We compare ordinary walkie-talkies, text mesh networks on LoRa boards and MeshTRX voice — what each can do and where each runs out.
Read →The button that pretended to work
Three complaints in a row, and not one of them a radio bug. A look at the errors that live at the seam between firmware and interface: a command that never went on the air, an icon that read backwards, and a false alarm caused by the test itself.
Read →Encryption in 39 bytes
At the time of writing MeshTRX traffic was unencrypted (encryption arrived in 4.4.19). Here is why "just turn on AES" does not work in a 39-byte packet, what an authentication tag costs in milliseconds of air time, and what a shared channel key actually buys you.
Read →A repeater doubles your range and divides the air
How forwarding works in a LoRa network: TTL, memory of forwarded packets, and the channel arithmetic showing why three repeaters cannot carry voice. Plus the story of a counter that swallowed every second phrase.
Read →One chip pin and fifty-eight decibels
A look at the bugs that surfaced only once the radios reached real people: an amplifier bypassed entirely, WiFi jamming reception, "not delivered" marks on messages that arrived. And why a two-board bench cannot catch everything.
Read →A crowded band: interference, channels, and moving a whole group at once
In a city the 868 MHz band is shared with door phones, meters and alarms. How the radio learned to find a quiet channel, why everyone has to move at once, and the mistakes we made getting there.
Read →Five kilometres on paper, two in the field
First range measurements on live radios: solid voice up to two kilometres, text further out. Why voice gives up before text does, what a repeater changes, and why comparing this to sensor networks is unfair.
Read →How voice fits into LoRa
LoRa was designed for humidity sensors, not conversations. Here is what it took to fit speech into that channel: Codec2 at 3200 bps, a 39-byte packet, a ten-second limit — and what we gave up for it.
Read →