SPI testing and register read/write

A project log for 500mW (27dB) ISM Band Transceiver

This is an ISM band transceiver utilizing the Semtech SX1238. Similar to the popular RFM69 except with an added power amplifier on transmit.

jon-thomassonJon Thomasson 04/26/2018 at 13:120 Comments

The boards passed the initial magic smoke test. I brought the boards up with a current controlled power supply and to my surprise no magic smoke escaped! After that I wired up the SPI bus to an 3.3v Arduino pro mini to see if I could communicate with the transceiver. 

I wrote a simple sketch that reads/writes to various registers. The idea here is that if the SPI bus isn't working, it's pointless to do any further testing until that can get sorted out. The sketch simply reads the register data to a serial console so I can check it with the default parameters of the datasheet. Here's the results from the SPI testing:

It looks like the register values match! Cool, so onto transmitter testing next…