Any examples of direct read & write of nRF51822 registers?

RE: Any examples of direct read & write of nRF51822 registers?

RK — Sun, 06 Sep 2015 08:12:24 GMT

Ah yes - I don't know why that macro define is there as the nrf51 series never had SPI with EasyDMA, the SPIS one does work as that does have DMA. I see it even defines SPIM1 at 0x40004000 which is just wrong.

The nrf52 series finally does implement an SPI master with DMA so it's valid for that chip, but, yes, not for the 51822.

RE: Any examples of direct read & write of nRF51822 registers?

Doug_H — Sun, 06 Sep 2015 07:52:37 GMT

That's it for sure. I got sidetracked by using the incorrect macro. There's a macro called NRF_SPIM1 (for SPI master I assumed) and it's mapped to a structure that maps pointers to the TX and RX data buffers among other things. Turns out this structure isn't used in any of the examples you suggested, so I switched over to NRF_SPI0 and accessing the TXD and RXD is a piece of cake. Thanks again for your advice.

RE: Any examples of direct read & write of nRF51822 registers?

RK — Sun, 06 Sep 2015 06:06:25 GMT

From memory

NRF_SPI0->TXD = data

But check the spi master driver if you want examples of that.

RE: Any examples of direct read & write of nRF51822 registers?

Doug_H — Sun, 06 Sep 2015 04:49:49 GMT

HI RK, thanks for your help on this. I'll go over the files and examples you suggest. I mostly have found what I need, just stuck on how to write to the SPI TX Register in the chip. I'll keep plugging away.

RE: Any examples of direct read & write of nRF51822 registers?

RK — Sun, 06 Sep 2015 02:14:09 GMT

What do you mean the macros aren't accessible? They are all in nrf51.h and nrf51_bitfields.h and just about any one of the peripheral drivers has multiple examples of reads and writes in them. Look at the spi driver in your SDK, look at nrf_adc.c in the drivers_nrf/hal subdirectory.

RE: Any examples of direct read & write of nRF51822 registers?

Doug_H — Sat, 05 Sep 2015 10:15:14 GMT

The registers are mapped to pointers to structures in nrf51.h

Be careful with SPI mapping. Use NRF_SPI0 or NRF_SPI1 NOT NRF_SPIM1

uint32_t spi_conf_reg;

spi_conf_reg = NRF_SPI0>CONFIG; 
RTT_PRINTF("SPI0 REG: %x\n", spi_conf_reg);