Got this: http://learn.adafruit.com/adafruit-airlift-featherwing-esp32-wifi-co-processor-featherwing/overview
Giving up after a few hours trying to make Teensy 4.0 to talk to it.
Getting “Communication with WiFi module failed!” in C:\Users\Homer\Documents\Arduino\libraries\WiFiNIN A-master\examples\ScanNetworks\ScanNetworks.ino
Had to modify this: C:\Program Files (x86)\Arduino\hardware\teensy\avr\cores\teensy4\Pr intable.h
It needs this: #include <stdlib.h>
VUSB – USB power
3.3v – Normal 3.3v power
Ground – Ground pin
Pin 5 – AirLift CS pin
Pin 6 – AirLift Reset pin
Pin 9 – AirLift busy pin
Pin 10 – AirLift GPIO 0 pin (used to put the ESP32 into bootloading mode if you soldered the jumper)
Pin 11 – SPI MOSI
Pin 12 – SPI MISO
Pin 13 – SPI SCLK
These are not connected. As I understand, they are needed for firmware upload only and this ESP32 is supposed to be pre-programmed:
Pin 0 (RX1) – AirLift firmware upload (must join a solder jumper to use)
Pin 1 (TX1) – AirLift firmware upload (must join a solder jumper to use)
Have the “3.3” jumper on the top soldered.
If anybody has it working, please share your wiring and the rest.