DB1NTO APRS Transceiver

After a few months of development, I can now imagine the presumably world’s smallest APRS transceiver. It is not only able to send a tracker of position data, but also a receiver can which releases other APRS APRS decode and display TV channels!

This includes APRS position reports incl. Comment (even mic-e), messages (SMS) and status messages. In position reports the distance and direction in “degrees” to the transmitter will be displayed.

My greatest thanks go to Mark -> http://unsigned.io/ of me with his “Micro Modem” and the free software “LibAPRS” -> https://github.com/markqvist/LibAPRS has enabled this tracker ever.

The core of the transceiver is a ATmega 328P (“Arduino”).

The transceiver is about as small as a matchbox (only 2 x 3 x 5.7 cm!), Weighs incl battery & casing (without antenna) only 38 grams and includes the following components.:

–2m transceiver (transmitter and receiver) with 0.5 / 1 Watt switchable transmission power
–GPS receiver
–Graphics-capable OLED display with a resolution of 128 x 64 pixels
–500 mAh lithium ion battery charging control
–Micro USB port for battery charging
–Two control keys

The following functions are currently supported by Tracker:

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Menu with 9 points

–Device on / off
–Volume 1-8 (NF audio for decode)
–H transmission power (1W) / L (0.5W)
–Reset GPS timer
–APRS Symbol (Primary Table)
–Disable recipients, send only positions (APRS tracker), longer battery life
–Set SSID
–Set callsign
–Set Time Zone

I have taken a lot of thought about the software and battery-saving features.

For example: GPS is activated cyclically in battery operation and off to save battery. When the device is used in a building without GPS reception, the cycle for GPS search is automatically extended. Is connected to external power (USB), this feature is automatically disabled and GPS is constantly on.

Position reports are sent only if they have a minimum distance to the last position report.

The case I have drawn in Sketchup and printed out even with my 3D printer (Prusa i3).

Remember me a lot of inquiries from around the world are currently being addressed through this project. Currently I would like to publish any details (schematics, PCB layout and software) for this transceiver. I therefore ask not to send such requests.

Many greetings

Taner Schenker

DB1NTO