Well, we DID test it again!
Our teacher took the transmitter out to the highest point of Peola Rd, west of Clarkston. Then drove out toward Waha, southeast of Lewiston. After reaching 21.5 miles, he lost line-of-sight as the road wound up the hill toward Waha. So, in short: An OUTSTANDING success!
Consider: a 1/10watt transmitter sending digital signals to a transmitter 22 miles away. (I believe it could reach much, MUCH farther) That’s a much less powerful transmitter than your phone and WAY less power than a walkie-talkie. And then picked up by a 2-inch long antenna.
We can do this because of a new radio-protocol called “LoRa” (for Long Range) which allows the receiver to pick the data out of the noise, even though the data is *quieter* than the noise. That blows me away!
Anyway, our transmitter parses the data from the GPS, then transmits the time, Lat, Long, Alt, and external temperature.