Very simple SPI Code

[Julian]

I am really struggling to get my ADXL345 SPI code working. Everything works fine on a LPC1768 and all outputs are fine on the nRF51822 Eval board, but there is no activity on the MISO pin. Is there any reason why I could not implement a simple method whereby I write to the TXD register and monitor the Events Ready pin before reading the received data?

[Stefan Birnir Sverrisson]

Hi Julian

Have you looked at the SPI examples in the nRF51 SDK?

Update 17.12.2014 I do not have something really simple SPI set up, but I think it should be possible to do it in these steps:

• Initialize the SPI master, similarly as is done in the spi_master_init function in the spi_master_example.
• Define the SPI IRQ handler and initialize it.
• Write a byte to TXD

Anyway I think the easiest way to move forward is to use the SPI driver in perhaps a more simple way than the SPI loopback example does:

• Define an event handler in your main function
• create RX and TX buffers and initialize them with data
• Initialize the SPI_0 master by calling spi_master_init with the name of the event handler you defined
• Call spi_send_recv function to send and receive data on the SPI
• Monitor your configured SPI pins with a logical analyzer or oscilloscope.
• First step is to see the clock signal on CLK pin and your TX data clocked out on MOSI pin.
• Next step would be to loop that data back into the MISO pin and check the RX buffer