[Jelmer] just recently discovered his old pager in the middle of a move, as well as decided to terminate it as much as relive his fond memories of getting a page. He soon found that the pager’s number was no longer active as well as the pager’s network was totally shut down. To bring his pager back to life, [Jelmer] developed his own OpenWRT-based pager base station that emulates the POCSAG RF pager protocol.

[Jelmer] opened up his pager as well as started probing signals to determine what protocol the pager used. soon he discovered the RF receiver as well as decoder IC which implements the POCSAG pager protocol. [Jelmer] began going through the sparse POCSAG documentation as well as assembled sufficient info to implement the protocol himself.

[Jelmer] utilized a HLK-RM04 WiFi router module for the brains of his build, which talks to an ATMega that controls a SI4432 RF transceiver. The router runs OpenWRT as well as produces POCSAG manage signals that are transmitted by the SI4432 IC. [Jelmer] effectively utilized this configuration to send manage signals to a number of pagers he had on hand, as well as plans on utilizing the configuration to send customizable alerts in the future. [Jelmer] does note that operating this gadget may be unlawful in many countries, so as always, inspect regional frequency allocations as well as legislations before dealing with this project. inspect out the video after the break where a pager is initialized by [Jelmer]’s transmitter.