I have several Pro Mini 5V from sparkfun and also a couple RFM22B radios.
I cannot find any solid sources for connecting the two together. I have found a few sources for the Pro mini 3.3v. Is it possible to use the pro mini 5v with this radio? If so does anyone have any sources or advice as to getting started?
I would suggest that your search has been a little less than perfunctory... There are MANY examples of resistive dividers in this forum.
The simplest is a 4K7 and a 10K resistor in series. One end of the resistor network is grounded, the mid point is the 3V3 point and the open end is the 5V point.
The exact values are simply a 1/3 - 2/3 ratio. 470R and 1K will work as well as 330R/910R...
Doc
I tried that
What I have done is for the main voltage, and any SPI comms pins from the arduino to the RFM, placed a three 220 ohm resistor to ground divider network. With the 3.3V coming after the first resistor off the input.
I am then using the RF22 server example and monitoring through serial window.
I get the RF22 failed, sending to server two line error and that is it. So I am wondering if I am doing something wrong in the connections. I found this and hooked up the wires accordingly:
Arduino RFM-22B
GND----------GND-\ (ground in)
SDN-/ (shutdown in)
3V3----------VCC (3.3V in)
interrupt 0 pin D2-----------NIRQ (interrupt request out)
SS pin D10----------NSEL (chip select in)
SCK pin D13----------SCK (SPI clock in)
MOSI pin D11----------SDI (SPI Data in)
MISO pin D12----------SDO (SPI data out)
/--GPIO0 (GPIO0 out to control transmitter antenna TX_ANT
--TX_ANT (TX antenna control in)
/--GPIO1 (GPIO1 out to control receiver antenna RX_ANT
--RX_ANT (RX antenna control in)
This did not work for me though, so i then also connected D3 to GPi02 on the RFM22B as per the Sparkfun RFM22b Shield schematics, and still could not get it to succesfully launch the radio. I am currently offshore on a shippin vessel so i do not have access to level shifters, i had to make do with the resistor network. Is there something special that has to be done to be able to connect with the pro mini?