Radio Group/Pager

Pager
Primary Contact	Asj
Created	27/03/2024
Completed	{{{completeddate}}}
Dormant	{{{dormantdate}}}
Version	{{{version}}}
Members	{{{members}}}
Manufacturer	{{{manufacturer}}}
Model	{{{model}}}
Location	Screen Printing Area
GitHub / Repo	GitHub
Status	Complete
Type	Members Project
Live Status	{{{livestatus}}}
QR code

We have a pager transmitter running from within the hackspace. The station has been allocated the callsign MB7PNH (Pager Nottingham Hackspace), and is built using an Adafruit Feather LoRa board, which has an RFM69 module. There are more details about this, and the PCB, on Aaron's website

MQTT Topics

Transmission of pager messages using MB7PNH without an amateur radio license is against the law - these topics are not listed on MQTT Topics or use the nh/ topic prefix for that reason You must have an amateur radio license to transmit messages via this node. These topics are available via jarvis.

POCSAG MQTT Topics

Topic	Description
pocsag/send	Sends a pager message to a specific RIC. RIC and message are separated with a pipe symbol e.g. "300424|Hello Aaron!"
pocsag/power	Taking a value of either "ON" or "OFF" - this can be used to power down the transmitter if there is an issue (this is a requirement for unattended nodes).
pocsag/status	Sending an empty message to this will return: the number of transmitter messages (.../tx_count), the reconnect count (.../reconnects), and, the power status (.../power). It's probably worth subscribing to pocsag/status/# if you want these.

RICs

The addresses for these have been generated randomly. There is nothing stopping you from programming a pager to receive messages as these RICs, if you happened to have a pager and wanted to receive notifications while you're in the space. You do not need an amateur radio license to receive pager messages. 👀

RICs

RIC	Purpose
754542	Receive alerts for Hackspace Instrumentation, e.g. service becomes unavailable or back up again. This was added to the Discord bot as it was already processing these status messages.
307040	Hackspace Doorbells, also sent via Discord bot.
224	Automatic date and time. This is compatible with AlphaPoc (and similar pagers). Not sure about others... This can actually be sent to any RIC that the pager is subscribed to - it just has to be in the right format to set the date/time, and won't result in a notification appearing. It's sent from a shell script every two hours. This is literally just mosquitto_pub -t 'pocsag/send' -m "224|YYMMDDHHMMSS$(date +%y%m%d%H%M%S)"

Responding to a failure

If there is a failure with this pager node, or it's reported that it is causing interference, it should be powered off immediately. This can be done from jarvis by running

mosquitto_pub -t pocsag/power -m OFF

The default state after plugging in the transmitter is off. If the connection the MQTT server is lost, the ESP8266 will pull the Adafruit Feather's ENable pin low, which turns off the 3.3v regulator, preventing power from reaching the RFM69 module.