Google Maps on JETI Transmitters

A Lua app can now put Google Maps on JETI transmitters with lots of useful functionality.

In the July 2021 issue of new RCSD, I wrote about Dave McQueeney’s Lua application for JETI transmitters (see Resources, below) that gives pilots a very fast method of trimming for crow brake. Now I can present Dave’s latest amazing app for JETI radios: Google Maps on the JETI transmitter screen. With this you can see the position of the model in real time, see its track history, colour code the track with a telemetry value, get spoken warnings about no-fly zones, and do GPS triangle racing for gliders with spoken directions around the race course and calculation of race points. This app has taken a lot of development but it is very sophisticated and we are sure that you will find it very useful. Any information that the pilot needs to know during a flight is spoken by the transmitter, so there is no need to take your eyes off the model and look at the screen while the model is flying. In fact the transmitter screen can display other telemetry screens, not the map, and the pilot will still be given all the spoken warnings and steering directions.

The app is free and only requires that the model has a GPS sensor that works with JETI radio. Most of my testing was done with a homemade GPS using the rc-thoughts.com design, which cost me around US$15 for the parts, so it allows pilots to enjoy triangle racing for very little cost. The triangle racecourse can be modified to any size and length of time, making it possible to race against yourself with even a small foamy glider.

If your flying sites have no-fly zones, these are easily programmed into the maps. The app then gives you spoken warnings about approaching the zones, entering the zone and leaving the zone. The zones are also shown with a red line on the map display so that the position of the model in relation to the zone can be very clearly seen.

This photo shows the transmitter screen as I sit with a model in my back garden. The screen displays a Google Map in satellite view with an aeroplane icon right where the model is!

The next photo shows the transmitter screen after a short flight of my Multiplex Cularis glider from a grass airfield. The corkscrew path of the model while following a thermal down wind is very clearly seen.

This photo shows the result at the end of a short six minute GPS triangle race using a foam glider. Each lap is a different colour of track making it easier to follow each one. The app displays data about lap times and speeds, scores and penalties. Flying the race does not require the pilot to look at the screen at any time. Spoken information is given about height and speed before crossing the start line, any penalty due to height or speed is spoken as the start is crossed, and then steering and distance directions are spoken to each pylon in turn. Spoken instructions can be turned off by a switch while you go thermalling, and then switched back on when the race is resumed.

The picture below shows a short flight with the track colour coded for reception data quality. Almost all of the track is blue, indicating 100% of packets were received and acknowledged. Three short sections at random locations are changed to green showing a slight reduction in data packets acknowledged. In this case the reduction is well within acceptable limits but such a visual presentation of data can be used rapidly at the field to pinpoint any areas where there are thought to be recurring interference problems.

Putting a Google Map on a transmitter screen is not a matter of just installing a simple app, so we have full training videos on YouTube about how to get the maps and how to use all the settings to get what each pilot needs for each model. The training comes in three episodes: Episode 1 deals with the basics, Episode 2 the no-fly zones and Episode 3 covers GPS triangle racing. Now that the app has been published for a short time, feedback from other pilots who have used it has allowed Dave to make even more improvements to it, particularly the screen presentation of triangle racing, so by the time that you read this there may be an Episode 4 to explain the upgraded functions.

©2021 Harry Curzon

Resources

• In-Flight Setting of a Multi-Point Trim Curve for Crow Brakes from the July, 2021 issue of RCSD
• JETI — DFM Maps Episode 1:

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