Mini-APRS-Transceiver

PicoAPRS with GPS receiver (Kit)New

PicoAPRS
Antenna not included

"Worlds smallest APRS transceiver with TNC" offers many applications. Matchbox-sized, built-in GPS receiver.

The transceiver can not only be used as APRS tracker and receiver for APRS data, but also as TNC (KISS protocol) for computer.
The graphical OLED display (128x64 pixel) shows received APRS packets such as position reports, APRS messages and status information.
When receiving position reports the distance and cardinal direction to the sender is shown.
Each of the four most recently listened in stations, including distance and cardinal direction as well as received messages are saved and can be retrieved via menu.

The own GPS coordinates are also shown, allowing the PicoAPRS to be used as a GPS receiver as well, for example for Geo Caching.
It's possible to save a fixed GPS position. This position is used when GPS positioning is not working. The fixed GPS position is then only used to show distance and cardinal direction of received stations.

All handling is done with two push buttons. With the help of a versatile menu system the transceiver can be individually configured and operated without using a computer.
The device comes almost fully preconfigured. Just save the call sign and you're ready to go.
The transmit power is approx 1 Watt and can be switched down to 0.5W. The own position data is transmitted as a compressed MIC-E APRS message to keep transmit duration as short as possible. This also helps to save battery power. Of course received messages in compressed MIC-E can be decoded and displayed as well.

The built-in 850mAh LiIon battery allows operation up to 10 hours* depending on configuration.
The HF receiver can be deactivated to save a lot of power, the Pico-APRS then functions as a pure APRS tracker. To extend battery lifetime even further the GPS receiver can be turned on and off in programmable intervals and the display can be dimmed.

The built-in micro USB connector is not only used to charge the built-in battery and for upgrading the firmware, but also to use the tranceiver as a USB-GPS mouse or as a TNC at a computer. This allows you to set up your own APRS Digipeater or iGate in a breath! We will provide a guide for this in the near future.

The transmitter utilzes a 7-pole low pass filter to suppress unwanted harmonics. The main processor is well known from the Arduino world, it's an ATmega 1284p. The current software uses a little more than half of the available memory, this allows for a lot of further developments in the future.

The tiny size of just 33 x 58 x 24 mm is close to that of a matchbox. The weight (without antenna) is just 52 gram. This is perfect to carry the Mini APRS Transceiver with you all thetime, whether on a hiking trip, on a journey with your bike or boat or even when skiing.

Even contacts via the ISS are possible, see image:

PicoAPRS Display

The Pico-APRS was developed by Taner Schenker (DB1NTO).

*) Depending on how frequently the position data is to be sent, whether APRS packets are to be received, whether the GPS receiver should be switched off automatically when not in use, and how often the display can be switched off

  • Menu items (to be extended):
  • Device off
  • Recently listened in stations
  • Received messages
  • APRS symbol
  • GPS status and display of GPS data: coordinates, absolute altitude, Maidenhead (QTH) LOCATOR, GPS date, number of staellites, course
  • USB mode (AUS, GPS, TNC)
  • Save current position as "default position"
  • Transmit power (1 Watt / 0.5 Watt)
  • Send Beacon
  • Time zones for adjusted displayed time
  • MyCall, SSID
  • Receiver exchange ON/OFF (OFF = just tracker for sending position report)
  • Frequency
  • Autoclose (closes received messages after an adjustable time automatically)
  • Display timeout ("screensaver")
  • GPS power saving (ON/OFF)
  • Display contrast (low / high)
  • APRS comment text
  • Information display
  • Reboot
Scope of Delivery pico-APRS
  • Included in the shipment (kit):
  • Enclosure with keys
  • Set of printed circuit boards, fully populated and tested
  • Manual
  • LiIon battery
  • Pin header for GPS board

No charger or antenna included. Thanks to the standard micro USB connector, the charger of any newer mobile phone can be used for charging. Alternatively, charge with any USB charger or USB port of a PC. For suitable USB cables see accessories list.
Any antenna with SMA connector can be used as an antenna, for some recommendations see accessories list. The tiny device makes you want to use a tiny antenna as well... but small antennas have a comparatively poor efficency, of course, and we only have 1W of transmit power. When used in a vehicle, an external antenna is recommend, for example a magnet base antenna.

The device is supplied as a kit. The two circuit boards must be mounted on each other and installed in the enclosure. The circuit boards are completely equipped and tested.


Improvement in Version 2

Since May 2017 the hardware revision 2 is shipped. This version of the PicoAPRS now has an acoustic buzzer which is used for key tones and signaling of received packets. Additionally the hardware was extended for accomodate a charge current display. A new firmware makes use of these innovations and offers other, new functions, see below. Older devices can use this new firmware as well, but the charging current display won't work.

  • New functions Version 2:
  • Display of charging current
  • Automatic on/off function when power is applied or removed from the USB socket, useful when using the PicoAPRS on a cigar lighter cable in the car.
  • Home position can be stored in EEPROM and recalled when no GPS reception is possible
  • Disable transmit intervals completely, e.g. for use as receive only pager
  • improved decoding of packets
  • Selection of distance units as miles or km or knots
  • Speedometer in GPS-Menu

The PicoAPRS can now fulfill functions of a POCSAG pager. In contrast to a normal pager the device can even send an acknowledgement when receiving a message. This shows the sender that his message has been received successfully. Messages can be sent directly to other radio amateurs ion the APRS system, or even to E-mail adresses. A simple reply function allowes the use of pre-made standard replies. Just select "Reply", select the prepared text and send. Ready!

While en route you can send a link to your position on aprs.fi to your destination by e-mail. With this function the people you are visiting can easily see where you are and when to start brewing a fresh coffee. This works worldwide without a mobile phone system, without roaming bills, without a mobile phone. The own callsign including SSID is embedded in the link, the recepient just needs to click on the link.

The new tactical 'follow' function is helpful for example when skiing with a partner. Just select the callsign of the partner, select 'follow' and you will continously see the position and direction of the followed station. When receiving new position reports the display is updated automatically. Or you can use this function while driving in a convoy with multiple vehicles.

Order No.
PICOAPRS PicoAPRS Kit 199.00 € Buy now New Not in stock, back on: 25. Aug. 2017
Info freight charges
Link: Download of Drivers, Firmware (open a new window)
Link: Bedienungsanleitung (DE) (open a new window)
Link: User Manual (EN) (open a new window)
Link: Changelog (EN) (open a new window)

PicoAPRS Mount

PICOAPRS Mount PICOAPRS Mount
PicoAPRS Mount PicoAPRS Mount

Mount for PicoAPRS. Can be attached anywhere thanks to the included Velcro strip. The USB port stays accessible.

Order No.
PICO-CLIP Mount for PicoAPRS 15.80 € Buy now New In stock, shipped in 1 or two days.
Info freight charges

Recommend equipment and magnet base antennas

Equipment and magnet base antennas
Order No.
17023 DIAMOND SRH-805 equipment antenna, length 4,5cm 18.50 € Buy now In stock, shipped in 1 or two days.
17021 DIAMOND SRH-815S equipment antenna, length 15cm 21.00 € Buy now In stock, shipped in 1 or two days.
17022 DIAMOND SRH-36 equipment antenna, length 36cm 31.00 € Buy now In stock, shipped in 1 or two days.
20117.SMA DIAMOND MR-77S magnet base antenna, 4m cable, base 65mm diameter 36.00 € Buy now In stock, shipped in 1 or two days.
20119.SMA DIAMOND MR-75S magnet base antenna, 3m cable, base 30mm diameter 31.50 € Buy now In stock, shipped in 1 or two days.
20111.SMA No-name magnet base antenna, 3m cable 22.90 € Buy now In stock, shipped in 1 or two days.
40074.06 USB/Micro-USB cable, 60cm 3.90 € Buy now In stock, shipped in 1 or two days.
40074.1 USB/Micro-USB cable, 100cm 4.50 € Buy now In stock, shipped in 1 or two days.
42854.02 Adapter SMA-plug(m)/BNC-jack(f), ultra short, black 11.40 € Buy now In stock, shipped in 1 or two days.
35050 Secondary battery LiPo 3,7V/850mAh 8.50 € Buy now In stock, shipped in 1 or two days.
35051 USB battery charger 8.50 € Buy now In stock, shipped in 1 or two days.
Info freight charges

Here are more equipment antennas.

USB charger to charge spare batteries without the device.
A maximum of 4 batteries can be charged simultaneously, with charge control indicator. Requires a USB connector as power supply.

35051: USB charger
35051: USB charger side view
42854.02: Adapter SMA-plug(m)/BNC-jack(f)
Pico-APRS PicoAPRS Production
testing PicoAPRS PicoAPRS Functional test

Customer Feedbackto the PicoAPRS

A customer write in December 2016

From: ON8SD
    To: WiMo

   It was worth the waiting! PicoAPRS, the smallest APRS-transceiver in the world is working like a charm!
   DB1NTO had done a fantastic job! Next stop, trying to find a good antenna to get the most of the 1W
   output because this one has to become an emergency device while trailrunning !
   ON8SD