ESP32 probe code complete

Yesterday, I got the ESP32 version of the probe up and running with the following setup:

• Microcontroller: Espressif ESP32-DevKitC
• Pressure sensors: Honeywell HSCMRRN060MDSA3
• Thermometer: Sparkfun TMP102 breakout
• Barometer: Adafruit BMP388 breakout
• Battery charger: Sparkfun Battery Babysitter
• Battery: Panasonic NCR18650B 3400 mAh

The code is in the firmware/airball_probe_esp32/ directory of our repo. This verifies that we can connect to our SPI and I2C sensors and get battery statistics over I2C, and broadcast the results by establishing a WiFi base station and broadcasting UDP packets on a well-known port.

The ESP32-DevKitC bundles a lot of the USB and power regulation machinery together, and uses an obsolete USB part, so I am hoping to bench-test a more stripped-down setup before spinning up a custom PCB. To that end, I need access to the individual pinouts of a raw ESP32-WROOM-32U module, and so this is what I made:

I will be reporting more on the following --

1. Verifying data rates and reliability with the UDP transport.
2. Battery charge time and battery life with the new battery.
3. Results of trying out the more stripped-down ESP32 setup.

If this all checks out, then we are well on our way to a really compact, and relatively low-cost, version of our probe electronics. Stay tuned!