Hello! I am looking for a review of my design for a small rocket altimeter called "Peanut". It has two pyro channels for firing 2ohm e-matches (1A nominal firing current), is powered by LiPo or Li-Ion batteries (3V7 nominal, up to 4V2), has a Bluetooth antenna, USB programming/file download interface and a barometric pressure sensor. There's a piezo arming buzzer, continuity indicating LEDs on the pyro channels, battery and pyro voltage monitoring (through the onboard ADC) and all data will be logged to internal flash memory.
This will be a 4-layer board (SIG, GND, 3V3, SIG) and I will be ordering it impedance controlled for the Bluetooth RF trace. I am mainly concerned with the Bluetooth circuitry, as I had to add a matching network with 0201 components recommended by the Espressif application notes. This is my first time working with RF modules that aren't already integrating with their own matching networks (I've also only worked with the lower-speed LoRa bands).
As this is an altimeter for rockets, I took a slightly (maybe unconventional) approach to the buttons that would typically put the MCU in programming mode; I made them jumpers instead of push-buttons. This is because of high-vibrations in the rocket which I don't want to accidentally trigger button pushes. It is an approach I have taken on other high-powered rocket hardware before.
All of the design files are available on GitHub: github.com/linguini1/peanut
There is this handy web-based KiCad project viewer as well if that makes your review easier: https://kicanvas.org/?github=https%3A%2F%2Fgithub.com%2Flinguini1%2Fpeanut%2Ftree%2Fmain%2Fpeanut