This open source wildlife tag uses the Argos system currently aboard 7 satellites to track any non-marine animal on Earth. This tag is specifically designed for use on small birds, but can be used on any terrestrial wildlife as well.
Current commercial solutions for bird tracking are bulky, heavy, and expensive. Certain trackers on the market can cost up to $3000 per tag. With this project, we aim to provide a cheaper and lighter solution for researchers around the globe.
CNES plans to have up to 25 nanosatellites with the Argos system onboard in orbit by 2023. These new satellites will give 15 minute location updates with accuracies up to 150m.
SPI flash orientation was fixed and the chip was immediately detected by my programmer. No problems there.
Adding a 43K resistor (top left, 0603, not soldered in image) to the MPPC pin didn't seem to do much. I'm probably going to figure out the solar charger in a separate PCB so I don't have to order 6-layer boards every time.
It turns out that I also had the wrong footprint for the 1.8V buck converter IC (top center, 8-ball BGA, TPS62748). The IC is 0.4mm pitch, and the footprint in the KiCAD default library was 0.5mm, I didn't notice.
For some reason, the same chip in the last batch was placed so perfectly in the center that it didn't raise a problem on both boards (I have 2 boards assembled each revision).
This time, none of them worked.
One was drawing >500mA idle and heating up like crazy, the other one just had nothing on the 1.8V rail.
Hotspot on the top is the 3.3V LDO, the one on the bottom is the 1.8V buck. (alignment’s pretty bad)
No big deal though, I just removed the 1.8V buck converter and soldered a wire to it. I'll feed 1.8V manually while testing.
More updates on the RF section coming soon.
Also, if anyone has any idea of how to make the solar charger IC (LTC3105) work properly, please leave a comment.