SPI communication between nRF51422 and Arduino

[Ankit]

I want to set up an SPI communication between nRF51422 SOC (integrated on nRF51 DK) and Arduino board. I know that it is possible since I've read it in various posts and nRF51 reference manual. But, I couldn't find a working example for it (SPI) in the nRF51 SDK, as is given for UART communication.

I have read the SPI master loopback example and the SPI slave example, provided with the SDK, but I couldn't comprehend whether they could be used for TX or RX from nRF51's side. If they can be, then how?

For the SPI TX/RX from the Arduino's side, I've read the Arduino SPI Library and trying to implement it, in a similar manner as this (www.arduino.cc/en/Tutorial/SPITransaction). Does it look fine? If not, then what should be used instead?

[David Edwin]

You can take a look at the SPI example where the nRF51 is the SPI slave and the Arduino is the SPI master. This is a 5 wire SPI interface (MISO, MOSI, SCK, REQN and RDYN) The code for this is part of the https://github.com/NordicSemiconductor/nRF51-ble-bcast-mesh

The Arduino SPI master code is available in "application_controller/serial_interface" folder. The readme for this folder has additional documentation links.

The nRF51 SPI slave code is present in the "rbc_mesh/src/serial_handler.c" , this should provide you with a working example.

[Ankit]

Thanks David for the link. It is pretty much what I was expecting. Follow-up: The example that you provided above would help me setting up a mesh-connection using "Bluetooth". I want to connect 8 to 12 devices in my network. Is it possible to achieve so using the Bluetooth SoftDevice? Also, does that example provide peer-to-peer support among all the nodes, or would I have to set up a "master" to control the entire mesh-connection? If it is not possible to connect 8 to 12 devices using "Bluetooth", can that example be used (with some modifications) to set up the mesh-connection using "ANT+"? If so, kindly explain the modifications to be done to the above example, as I'm a newbie. I've read that ANT can support upto 8 connection channels simultaneously, where each channel can support upto 65533 nodes. So, it would be possible to add more devices to my network in the future, using ANT.