non-hardware SPI pins for MIRF (nRF24L01+)

Other Hardware Home Automation
1

Hello,

I am working on small battery power sensor nodes using the nRF24l01+ radios

So far I have all the nodes working but to bridge them to the a web service I am using this board.
http://imall.iteadstudio.com/development-platform/arduino/arduino-compatible-mainboard/im120410001.html
Reading the specs on the board I see that it's socket for the nRF24l01 it is not using a hardware SPI pin assignment supported by the MIRF library.
from the schematics the board has following nRF24l01 pins connected as below
MISO -D6 (not D12)
MOSI -D5 (not D11)
SCK -D7 (not D13)

Is it possible to configure the MIRF library to use these pins?
I am not too keen on using a different library for the radio as I would have to change it for all my other boards too.

Thanks

[subject title corrected by moderator]

2

See little-scale: SPI by hand for one implementation. I have seen some of the LCD display drivers like gLCD and Adafruit do this also but they use the Arduino low level digital line manipulation routines to speed things up.

3

No idea if mirf can use softspi, but you can also use the hardware spi pins with the cs/cn from the nrf24connector.

That is what I'm using with the Iboard Ex...

No idea why Itead has done this. There Nano breakout board does use the hardware spi for the nrf24...

4

I am going to make a PCB adaptor board that uses the SPI pins from the ISP connector near the nRF connector and break out the digital pins freed up.
It should allow me to use hardware SPI and give me 3 digital pins to play with.

I can't understand why they would not use hardware SPI but they must have their reasons as the newer variants of the boards also have the same pin mapping.
Maybe if I order a few hundred I can get them to change it.

5

There was a link to a softSPI version of the MIRF library on the USEFUL LINKS tab.
http://imall.iteadstudio.com/development-platform/arduino/arduino-compatible-mainboard/im120410001.html
See GitHub - andykarpov/iBoardRF24: Arduino driver for nRF24L01 on the iTeadStudio iBoard

Cheers!

6

That is the softSPI version of RF24 not MIRF,
The two libraries are different and configure the radio differently, It is not easy to get the two libraries to talk to each other.

When I was comparing them last year I ended up choosing MIRF because it compiles to about half the size and is much easier to use. This allowed me to make some Atmega88 based boards.

I have ended up just soldering some jumper wires to connect the hardware SPI. I am going to make some daughter boards to connect the MISO MOSI SCK pins of the ISP connector and break out the 3 digital pins freed up.