As I can see the SX1276 has an SPI interface. SPI can be full duplex, the CS pin selects the slave device and then on the clock pulses the slave transmits data on the MISO line. (Master Input Slave Output).

So answering your qustion shortly: yes, it can.

You are almost correct!

You need two of this module, but one 12V supply is completely enough. You can wire the 12V and GNDs together. You have to be careful, the power supply should be able to power both solenoids, so in case of two 2A solenoid you need a 4A supply.

You should use SPI pins, which is on 18 19 23 pins. (On the right side, in light blue background)

Hi!

I know it's a weird question, but is the battery charged up?

Have you measured battery voltage or 3V3 yet?

As far as I know in Europe the EIRP limit is 20 dBm, so I guess 21 dBm is absolutely okay. (There will be some losses on matching and antenna efficiency, so 21 dBm on the chip output should be fine.)

Woah, it looks great!

Well done, nice job there!

Usually you would fit anything that is sensitive to noises. The decoupling capacitors are great ideas, I also would fit xtal(s) there. Antenna matching circuit is also possible to fit there, but not necessary in my opinon. As an example, ESP modules also have an EMI shield on them covering everythin...

Hi! I don't know the exact pin numbering of your development board, but it is suspicious for me. On page 10 of the ESP32-C3-MINI-1 datasheet ( https://www.espressif.com/sites/default/files/documentation/esp32-c3-mini-1_datasheet_en.pdf ) pin 8 and pin 9 are EN and NC, respectively. This may be not t...