Programming RFM radio modules in Basic

[astanapane]

I did the simplest configuration connection between the PIC and the RFM69HCW.

Both of the boards are exactly the same. One will be the TX and the other will be the RX.

Still in a very early stage, and keep reading the SPI protocol.

[richard]

Is there any quick way to check whether the RFM module is powered up?

read a register on the module . write a new value to that register read the register again and confirm the new value


looking at your picture there are two wires missing on each module , that's never going to work

[Ioannis]

SPI is not RS232. Sure Richard spot it. You need to revise your connections.

Also, your caps around the crystal, what values are?

Ioannis

[astanapane]

Hi Richard and Ioannis, sorry for the bad quality of the picture.

Connections i believe are ok. But two wires werent visible on the first pic.

Capacitors are 22p and crystal is at 16Mhz. This combination seems to work just fine on my previous circuits.

[richard]

Also, your caps around the crystal, what values are?

on that subject why even use a crystal

Connections i believe are ok. But two wires weren't visible on the first pic.

wrong , did you even look at the schematic I provided ?

there are 5 connections needed

[astanapane]

Richard why do we need to 5th connection? i See there is a DIO pin.

EDIT POST: ok found that here:

https://learn.adafruit.com/adafruit-...akouts/pinouts

G0 - the radio's "GPIO 0" pin, also known as the IRQ pin, used for interrupt request notification from the radio to the microcontroller, 3.3V logic level

I still do not fully understand it but will be the reason.

[richard]

sdo is pic output and would be the mosi line [master out slave In] connect to the module input pin, should be marked mosi
sdi is pic input and is the miso line [master in slave out ] connect to the module ouput pin, should be marked miso

[astanapane]

I'm confused about the SPI connection.

In the manual of the PIC18F26K22 this is how do they have it Master and Slave.

The MOSI from Master goes to MISO on slave and the MISO from master goes to MOSI on slave. Which it seems for me to be the right connection.



But everywhere else on the NET i find it as following. MISO on Master goes to MISO on slave and MOSI on Master goes to MOSI on slave.

https://www.google.gr/search?q=spi+c...w=1422&bih=701