There is simple way to monitor, transmit, and create alert, (event), with a Arduino and transmit result data with POCSAG. There is a easy experimental way. Using Arduino and RFM22 board, as well you can use Si4432, you can send data on Pocsag QRG 439.9875Mhz Ham band.

I monitor GPS coordinates, temperature, with a DS18B20, and Vcc value, and create an alert if Vcc drop under 5volts.

Data are sended every five minutes, or instantly if alert event.

There is the result with PDW:

Some experimentation’s with small UHF PA, RFM22 board and Arduino UNO.

Arduino Sketch:

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