SPI example code for nRF51822 Eval Kit

RE: SPI example code for nRF51822 Eval Kit

max — Tue, 05 Aug 2014 07:53:27 GMT

Hi, How you configured SPI master to use ADXL362? i use \pca10001 example but i have an error if i take a SPI master example files from /nrf6310

RE: SPI example code for nRF51822 Eval Kit

Håkon Alseth — Mon, 23 Jun 2014 15:03:21 GMT

Hi David,

If you're using the eval-kit, the pins 8/9/10/11 are connected directly to the SEGGER chip, and it will drive some those lines high. Try changing them to other GPIOs.
You're using printf. Have you mapped printf to something? If not, it will crash the program.
Have you tried scoping the SPI lines to see if the data going over the bus is sensible?
It is good practice to never let a embedded program return from main. add a while(1) in main.

RE: SPI example code for nRF51822 Eval Kit

David — Sat, 21 Jun 2014 08:11:39 GMT

I see, I'm currently using that example code (spi_master_example_with_spi_slave). However, my RXD always returns zero even though it was supposed to read a register with value of non-zero.

I've made sure to read the accelerometer datasheet (if you are interested here's the link: www.analog.com/.../ADXL362.pdf, page 19 onwards)

I've also made sure that I'm using the correct SPI Mode, correct clock, correct pin numbers and tried reversing the bits, but to no avail. I'm truly confused now, because I strongly believe this code should work, unless there is something else I need to do in that example code that I need to change to enable RXD to receive data? I don't think the component is broken either, although there is no indicator or such, so it is a hard to say in that regard.

Here is my code, if you don't mind checking: SPI Accel.zip

RE: SPI example code for nRF51822 Eval Kit

Håkon Alseth — Wed, 11 Jun 2014 14:39:10 GMT

Hi,

The spi_master_example in the SDK is a loopback example, meaning that it will send a sequence of data and expect the same data in return. If it does not receive the same data in return, it will return false and set the error LED. There's another SPI master example (spi_master_example_with_spi_slave) that works with the SPI Slave example in the SDK, if that is of interest.

The SPI-examples will not work out-of-the-box with that sensor. You'll have to map up the register definitions for your specific accelerometer and use the SPI init/send/receive functions to communicate with the external sensor, as we do not have any examples for that specific accelerometer.

Best regards Håkon