ESP32

The ESP32 devboard we need, should have a couple of pins exposed and the most import thing is that it has 4MB of flash memory!

The CC1101 transceiver we are using, has a Texas Instruments CC1101 chip (datasheet) and has the following pinout:

The pin connections are according to the table below:

Pin	CC1101	Pin name	ESP32	Pin nr	Board
L1	GOD1 (MISO)	GPIO-19	SPI_MISO	D19	F
L2	SCK	GPIO-18	SPI_CLK	D18	G
L3	GDO0 (TX)	GPIO-13		D13	-
L4	GND	GND		GND	N
R1	GDO2 (RX)	GPIO-12		D12	-
R2	MOSI	GPIO-23	SPI_MOSI	D23	A
R3	CSN	GPIO-5	SPI_CS0	D5	H
R4	3.3V	VDD 3V3		3V3	O

Pin is the pin number on the CC1101 board (L=Left, R=Right). Pin nr is the pin als printed on the ESP32 PCB. Board is the letter on the connection PCB I made to connect the ESP32 pins to the CC1101 board.

This is a bit different from ESP-Somfy hardware guide, as the pinout doesn’t seem to be the same for the serial TX/RX pins. May the ESP-Somfy uses bitbanging and not the hardware serial port? It seems that the communication with the CC1101 isn’t exactly serial communication! I first tried to use pin 16 (U2_RXD) and pin 17 (U2_TX2) but that didn’t seem to work - I could see log entries, but no transmission. Then I changed to the original pin settings as described in the manual (as displayed above). But again: only logs, and no transmission. But when I swapped the configuration, I could send out the correct codes, but no logs! Finally, I set both RX and TX to pin 13. That worked! It seems that my version of the CC1101 can only work via GDO0 and GDO2 doesn’t do anything…