A Pocket Elmer on the Mesh

Overview

An elmer is the experienced operator who answers your questions when you are getting started. This is the same idea, built into the station’s mesh gateway: an intelligent assistant you can ask from a handheld, with no internet at the radio.

Send a short question on a private channel and a short answer comes back. The radio has no internet. The assistant runs at the station, and the mesh carries the question and the reply.

  handheld:  "best band to reach Portland right now?"
      |  LoRa, private channel
      v
  station gateway  -->  the assistant (runs here, not on the radio)
                            |  answers in one short line
                            v
  handheld:  the answer, back over the mesh

How it runs

The gateway hands the question to a local assistant process and sends the reply back over the mesh. Two things matter about how it is wired.

First, a mesh message can never run anything on the station. Every tool the assistant could use to touch the box is disabled, and the question is passed as input, not as a command line. The worst a sender can do is ask a question and get text back.

Second, it is location aware. The gateway knows the asking node’s grid from its shared GPS and includes it, so answers about bands, repeaters, or portable operating are framed for where the operator actually is.

Answers are kept to a line or two, because mesh messages are small and the point is a quick, useful reply, not an essay.

Conversational

Follow-ups keep context. Ask a question, then ask “what about tonight” and it knows you are still on the same topic. A fresh start is one word away, and an idle thread resets itself so it does not grow without bound. For a field assistant, short and current beats long and complete.

Why this is worth having

Out in the field, the useful questions are small and specific. What band. Which repeater. Is this frequency in the plan. Having that answerable from the radio in your hand, with no cell signal and no app, is the whole point. It rides the same private-channel gateway as the rest of the station’s commands, so it reaches the field the same way they do, including over the internet when direct RF is out of range.

Lessons

• Disable everything by default. An assistant reachable from the air should not be able to do anything but answer. Tools off, input as data, no exceptions.
• Context from the radio, not the operator. Pulling the grid from the node’s GPS means location-aware answers without the operator typing coordinates.
• Small is a feature. A one-line answer that arrives beats a paragraph that does not fit the channel.