For some reason W6MRR-26 woke up today, but not yesterday. See the AMSAT Argentina site or APRS. So the trasnmitter is wonky but the altitude is looking good – 43K’. W3HAC also woke up today as it did yesterday but appears to by sitting on the ground in DM36II land. Stay tuned!
We will meet prior to HackaDay’s Supercon on Sunday, November 6 at 9 am in front of the the Los Angeles College of Music, 14 East Del Mar Blvd, Pasadena 91105
If all goes well you can track it on 20 m WSPR, WSPRnet.org or some of the alternate sites listed on WSPRnet as W6MRR & W3HAC. It will be moved over to APRS as soon as it shows up on WSPR . WSPR callsign W6MRR-26 & W3HAC-11.
Kazu AG6NS and I have been working on a couple of trackers. One is a dual band 2/20 m APRS/WSPR with other modes coming. It is based on an ATMega1284 processor, which is a 328 (used currently) with more memory and and running at 10 MHz, the safe limit for 3.3 V operation. Kazu has come up with code for it and I need to catch up with a revised PCB.
The other is a Raspberry Pi Pico based tracker. This is a longer range project. It will use the same Si5351 based modulator and filters for 2/20 m. The Picos are attractive as they have a dual core ARM Cortex-M0+ @133MHz which is far more powerful than the ATMegas.
The RP2040 chip has instructions for DIYing a board but I went the Raspberry Pi as it was the easiest path to start working on a design.
Due to the chip shortage, I may need to use through hole components for the output filters.
We are looking at a lot of fun things that can be done – SSTV data and cam, voice ID over VHF, crossband repeaters, and latex floaters. If you’re interested in helping out out or at least join in please get on our chatter list.
We will be meeting by the Berkeley Marina – https://maps.app.goo.gl/erjqu1VxkXkdZtqg6 We will be sending the same tracker with a new Yokohama balloon. It will be sending as W6MRR on 20 m WSPR. If it lights up it will be W6MRR-25 on APRS.
Kazu AG6NS ran out of space for more things like 2 m APRS and 20 m data over SSTV. I had tried a dual 2 m/20 m tracker before but gave up due to self interference. I was using a 6 g 0.5 W FM VHF transmitter module and it caused the ATMega1284 to lock up. QRP Labs had this problem and solved it with a metal can over the microcontroller chip. I had some leftover 1284s and am spinning up a new board. It will run at 10 MHz/3.3 V to conserve power. The 1284 has 128K flash vs 32K on the 328s. Kazu has already demonstrated APRS on 2 m but the 328 didn’t have room for WSPR and SSTV. A Si5351 with be used to synthesize the output signals. A separate LPF is on each of the the 3 outputs and a BME 280 is used for temperature, air pressure and humidity. I think we’ll need amplification to get anywhere with APRS but not 0.5W. If you’d like to help out with this – let us know.