I am trying to get a couple RF22 transceivers to talk to each other, controlled by 5 v. Nanos, and I find various comments about the wiring. As best I can tell, the RF22
has an interrupt which is an output going to the Nano, needs a chip select input, which can be held low if the radio is the only SPI peripheral, needs the MISO line, an output to the Nano, needs the MOSI line, which is output from the Nano, needs the SCK, an output from the Nano.
There are two lines RX_Ant, and TX_ant, which appear to be unneccesary for a simple arrangement, but I have seen at least one diagram which showed them tied to the GPIO pins. I do not have them wired to anything.
I have wired these up as stated above, using level shifters for the interrupt and MISO lines, and 4.7K/10K voltage dividers for the SCK and MOSI lines. Using the Radiohead RF22 library, I never get a successful initializiation.
If you have any experience with these, I'd appreciate hearing how you got them working.