nRF52832 SPI Master read results in "zeros"

RE: nRF52832 SPI Master read results in "zeros"

Sigurd — Mon, 30 Jan 2017 14:54:16 GMT

I'm glad you figured it out :)

RE: nRF52832 SPI Master read results in "zeros"

leey — Mon, 30 Jan 2017 14:52:09 GMT

Thank you Sigurd !. After spending some time enabling debugging and looking at the drivers, still can't find anything wrong. Then looking again at the scopes data; suddenly it all makes sense. We made a last minute change to power the nRF52 with 3.3V; what I don't realize is that the ADC is still powered by 1.8V; so the respond from the ADC is 1.8V digital logic, which is just below the needed threshold for logic states for nRF52(with 3.3V VDD). For the time being, I lowered the VDD to 2.5V and ALL is well. Thank again for all the response and help. It is not a wasted effort for me; as I am now more familiar with the Nordic SPI drivers and the approach in creating the drivers etc... Thanks, Lee

RE: nRF52832 SPI Master read results in "zeros"

leey — Mon, 30 Jan 2017 14:50:49 GMT

Thank you Sigurd !. After spending some time enabling debugging and looking at the drivers, still can't find anything wrong.

Then looking again at the scopes data; suddenly it all makes sense.

We made a last minute change to power the nRF52 with 3.3V; what I don't realize is that the ADC is still powered by 1.8V; so the respond from the ADC is 1.8V digital logic, which is just below the needed threshold for logic states for nRF52(with 3.3V VDD).

For the time being, I lowered the VDD to 2.5V and ALL is well.

Thank again for all the response and help.

It is not a wasted effort for me; as I am now more familiar with the Nordic SPI drivers and the approach in creating the drivers etc...

Thanks, Lee

RE: nRF52832 SPI Master read results in "zeros"

Sigurd — Mon, 30 Jan 2017 14:03:39 GMT

I just tested the spi-master example on the nRF52-DK, with these settings:

//APP_ERROR_CHECK(NRF_LOG_INIT(NULL));

//NRF_LOG_INFO("SPI example\r\n");

nrf_drv_spi_config_t spi_config = NRF_DRV_SPI_DEFAULT_CONFIG;
spi_config.ss_pin   = 8;
spi_config.miso_pin = 5;
spi_config.mosi_pin = 6;
spi_config.sck_pin  = 7;

and it worked just fine.

Also make sure that you are using the correct SPI mode. The default mode is "SCK active high, sample on leading edge of clock".

RE: nRF52832 SPI Master read results in "zeros"

leey — Sat, 28 Jan 2017 19:24:29 GMT

Commented UART, NRF_LOGs etc... from the sdk_config.h file; commented also GPIOTE option; still same issue ?

Probably something obvious but at the moment, can't seem to figure out why I cam not getting data as shown on the MISO pin itself ?

I am working on our own PCB board; so hard to change the pins assignment; try a few, but getting shorts in a few places; tiny pins and no test pads or vias to put test wires on.

Thanks, Lee

RE: nRF52832 SPI Master read results in "zeros"

leey — Fri, 27 Jan 2017 17:26:40 GMT

I am not using UART; so a straight copy of the SPI examples from SDK 12.2.0; I removed all calls to LED inits and replace the pin used from the ones used in the examples to my set of pins; noted that the SCK, CS and MOSI pins seems to work as I am getting expected MISO data(on the scopes) but not on internal registers

It seems that somehow maybe I need to add another init for pin P0.05 as it is also can be used as Analog input; so far this seems the only thing that I can think of.

I will look again at my codes and remove all relevant of any UART or any LOGs stuff

Thanks, Lee

RE: nRF52832 SPI Master read results in "zeros"

Sigurd — Fri, 27 Jan 2017 17:07:21 GMT

As seen here, Pin P0.05 to P0.08 are by default used by the UART. Please check if you are using the UART module. If you are able to, you should also try switch to different pins to check if that solves the problem.

RE: nRF52832 SPI Master read results in "zeros"

Roger Clark — Fri, 27 Jan 2017 07:09:50 GMT

You will need to post a snippet of your code, as you are almost certainly doing something wrong, as MISO clearly has data on it.

I would also check which pin you have connected to MISO vs what you have configured in the code