Espressif
From Wildsong
M5 hardware
M5StickC orange and wearable. Also has an 80x160 OLED display, a 6-axis accelerometer, and a microphone
Atom Matrix grey with 5x5 Neopixel LED matrix and a 6-axis IMU
[Atom Echo] white, with a speaker and microphone. It also has a Neopixel
which OS?
Arduino
or
Espressif IDF and FreeRTOS
JTAG debugging
https://mcuoneclipse.com/2019/10/20/jtag-debugging-the-esp32-with-ft2232-and-openocd/
Books and resources
Random Nerd