Tag: aprs
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Assembling and testing the tracker lab model
The picture above shows the PCB for the Arctic Tracker with most parts mounted. It was straightforward to solder the parts on the board, except the Teensy. It can be tricky since it need to have 37 pins soldered on it first, and these should either be soldered onto the PCB either directly or a…
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Designing a lab model
The Arctic Tracker project is not dead (yet). The idea is to develop a tracker device with traits like these: It is modular, it can be assembled mainly from existing modules. Should be fairly easy to assemble. It has plenty of computing room and is open source. It can be a platform for hacking and…
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Receiving APRS packets
Receiving and decoding of APRS packets is now implemented and it seems to work. It is more tricky than sending packets but there are a fair amount of examples to look at. For instance the BeRTOS TNC implementation. Ok, here is how it is done: First, the audio signal from the receiver is fed to…
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Transmitting APRS packets
APRS packet transmission is now tested and it works. It is clear that the SA818 radio module is not usable for this project. The time it takes to key up the transmitter and get a decent modulation running is far too long. In addition it seems to vary and it seems like there is some…
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Using the DAC
Can we use the 12 bit DAC of the Teensy 3.1 to generate AFSK (Audio Frequency Shift Keying) signals? Lets try. First, we try to generate sine waves with frequencies of 1200 or 2200 Hz. If we could quickly toggle between those two frequencies, it would support generating AFSK. The idea is to use a…
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Hamlabs is contributing to the APRS community
This week our APRS-IS server became an official member of the aprs2.net system. The APRS Tier 2 network is now represented in one more country, and this contributes to further stability for the APRS-IS system, linking the APRS world together.