Site Alert is a device that connects to the serial port of a UI-DIGI[A] APRS[B] Digipeater. It is used to provide local site information from a remote Digipeater site via APRS Telemetry data.
The data is transmitted every 30 minutes and includes the average of four supply voltage readings, the current in-building temperature, number of PTT’s and the current mode of the Site Alert. The Parameter, Unit and Equation messages are sent once a day.
Should the average voltage fall below a pre-programmed value Site Alert will turn off the Low Battery output until the average voltage reaches the upper pre-programmed value. This output can be used to control an external relay to remove power from the TNC and Radio.
SiteAlert provides protection from 'locked Digipeaters'. If the Digipeater does not transmit within a set timeframe it can be automatically reset.
The battery alarm or the external alarm inputs will cause an APRS Item and an APRS Message to be transmitted. Alarm Messages can be extended to an Email or SMS notification gateway.
Site Alert uses an Atmel AT90S2313 micro-controller, ADC0831 Analog to Digital converter, Dallas Semiconductor’s DS1820 Temperature sensor and DS1307 Real Time Clock.
Further information on SiteAlert can be found at SiteAlert Web page.