Not able to see log output in COM port for SPI.

RE: Not able to see log output in COM port for SPI.

Jørgen Holmefjord — Mon, 01 Oct 2018 20:10:12 GMT

You should not have to modify the SPIS example, the slaves does not care which device it is interfaced by.

I have attached main.c file that show how you can interface 4 different slaves that is connected to the same SPI instace for SPI master example:

devzone.nordicsemi.com/.../main.c

The slave SS pins should be connected to GPIO P0.12-P0.15.

RE: Not able to see log output in COM port for SPI.

BeaconBLE — Mon, 01 Oct 2018 17:38:21 GMT

Hello,

I am really sorry for the trouble, I am a beginner, if you could please help me with a gist of code changes that I have to do in the SDK 12.3 spi and spis example that would be great.

Thank You.

RE: Not able to see log output in COM port for SPI.

Jørgen Holmefjord — Mon, 01 Oct 2018 08:13:42 GMT

Yes, no changes to the nrf_drv_spi files. You simply set and clear the SS pin in use with GPIO functions nrf_gpio_pin_set/clear(). Note that you have to setup the SS pins using nrf_gpio_cfg_output() first.

The master is always the one initiating a transfer on the SPI bus. The slaves can not start transmitting by itself. You will have full control over which slave device is transferring in the master application.

RE: Not able to see log output in COM port for SPI.

BeaconBLE — Fri, 28 Sep 2018 06:15:26 GMT

So for changing the SS pin manually do I not do the changes in the nrf_drv_spi.h and nrf_drv_spi.c file and what other changes do I have to do for it to work. Also, when 4 slaves are transmitting how do I manage the timing because they cannot transmit simultaneously right. Is there a way to know whether the other slave is currently using the SPI pin or not?

Thank You.

RE: Not able to see log output in COM port for SPI.

Jørgen Holmefjord — Thu, 27 Sep 2018 12:46:19 GMT

Unless you are using the SD Card/FatFS library, I would recommend that you control SS pin manually, rather than modifying the driver as suggested in the link.

You cannot transmitt data from more than one device at a time on a single bus, then you need to setup multiple SPI instances. nRF51 support two SPI master instances.

The simples solution would be to configure the transmitter as a SPI master device and the 4 others as SPI slave. You can then set SS pin manually for each device and transmitt/receive from that device. Then move to the next device.

RE: Not able to see log output in COM port for SPI.

BeaconBLE — Thu, 27 Sep 2018 09:08:02 GMT

Hello Jorgen,

Thank you for your input. It helped me a lot. I am working on an application with 5 nRF51822 chips in one board, one of which is a transmitter and 4 of them are receivers(they receive the signal from a transmitter in a different board) which then send the received signal using SPI to the transmitter in the same board. So I saw your thread where you explained how to change the SS pin and send using SPI -SPI multiple SS pin thread . I need to transmit received signals from four different boards to a single board, so I wanted to know if the four chips can send the received signal using SPI to the one chip simultaneously, will there be a collision or how will it work? Also, can I change the SS pin value from the slave side? Basically, I am not sure about how I proceed with this setup if you could help me that would be great.

Thanks a lot.devzone.nordicsemi.com/.../My-setup.pptx

RE: Not able to see log output in COM port for SPI.

Hein — Wed, 26 Sep 2018 11:48:04 GMT

My bad sorry, it was the SPI and TWI that I had issues with.

RE: Not able to see log output in COM port for SPI.

Jørgen Holmefjord — Wed, 26 Sep 2018 11:34:58 GMT

By default, the logger module is not enabled in the examples. You need to set the following define in sdk_config.h:

#define NRF_LOG_ENABLED 1

[quote user="kernels"]Not sure about the 51, but in the 52 you can not run the SPI0 and UART0 at the same time, are they both configured for instance 0 ?[/quote]

This is not correct, UART does not share instance with other serial devices. Only SPI/SPIM/SPIS/TWI/TWIM/TWIS share base address.

RE: Not able to see log output in COM port for SPI.

Hein — Wed, 26 Sep 2018 04:56:37 GMT

Not sure about the 51, but in the 52 you can not run the SPI0 and UART0 at the same time, are they both configured for instance 0 ?