nrf52840 serial

RE: nrf52840 serial

haakonsh — Wed, 05 Sep 2018 10:01:01 GMT

I need you to read out the content of the UARTE[0] and [1]'s registers before your first transmission.

RE: nrf52840 serial

mtfurlan_t — Wed, 05 Sep 2018 09:05:15 GMT

My apologies, I saw the error of "no member named 'use_easy_dma'", and checked the documentation, where it is not listed: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.1.0%2Fstructnrf__drv__uart__config__t.html&resultof=%22%6e%72%66%5f%64%72%76%5f%75%61%72%74%5f%63%6f%6e%66%69%67%5f%74%22%20

That should be linking to the page for nrf_drv_uart_config_t in sdk 15.1.0

Documentation is actually the same for 15.0.0.

In nrf_drv_uart.h, we need the following to be true to have use_easy_dma:

defined(NRF_DRV_UART_WITH_UARTE) && defined(NRF_DRV_UART_WITH_UART)

Those are defined in the same file, if UARTE_PRESENT and NRFX_UARTE_ENABLED or NRFX_UART_ENABLED are set respectively.

Both of those are in the sdk_config.h, but both are actually overridden by /integration/nrfx/legacy/apply_old_config.h

In the end I had to enable UART_LEGACY_SUPPORT. in sdk_config.h

If you want I can test if it was actually a change in the SDK that made that necessary or if it was an accident on my end.

Either way, now that that is fixed, input still doesn't work.

main.c: http://ix.io/1m0J

sdk_config.h: http://ix.io/1m0K

RE: nrf52840 serial

haakonsh — Wed, 05 Sep 2018 08:19:27 GMT

"There is a bug where "use_easy_dma" which was removed from "nrf_drv_uart_config_t", is still used by "components/libraries/serial/nrf_serial.c" line 208"

- use_easy_dma is still a member of nrf_drv_uart_config_t. See line 192 of \integration\nrfx\legacy\nrf_drv_uart.h.

You need to set the necessary defines in sdk_config.h or the preprocessor will not let the compiler use it.

RE: nrf52840 serial

mtfurlan_t — Tue, 04 Sep 2018 19:21:36 GMT

I was trying to use blocking rx/tx calls.

I switched to using the event handler, and it never gets an event of type NRFX_UARTE_EVT_RX_DONE or NRFX_UARTE_EVT_RX_DONE

I was already calling APP_ERROR on the return codes of the driver calls, and that will block if it's not a success. The code doesn't block, so they're all returning NRF_SUCCESS.

Newest code: http://ix.io/1lZh

Also I updated to nRF5_SDK_15.1.0_a8c0c4d

There is a bug where "use_easy_dma" which was removed from "nrf_drv_uart_config_t", is still used by "components/libraries/serial/nrf_serial.c" line 208

I just commented it out, is that the suggested fix?

RE: nrf52840 serial

haakonsh — Mon, 13 Aug 2018 12:38:09 GMT

you need to pass a couple of event handlers to the nrfx_uarte_init functions, or all rx/tx calls will be blocking.

You also need to catch and check the return codes of your driver calls.

RE: nrf52840 serial

mtfurlan_t — Thu, 09 Aug 2018 14:11:11 GMT

This question has become "How do I use the NRFX UARTE driver to read input?"

In the code I posted, I'm already the NRFX UARTE driver directly, but it can only print and not read.

I changed the code I had to use both UARTs, and it can print to both without the modification from Jakub Rzeszutko in the linked post, but I still can't read from the UARTs.

It does not suffer from the issue of choking on data bursts.

main.c printing to two UARTs: http://ix.io/1jIS

RE: nrf52840 serial

haakonsh — Wed, 08 Aug 2018 13:14:41 GMT

You need to use the UART driver directly and not the app_uart library

RE: nrf52840 serial

mtfurlan_t — Tue, 07 Aug 2018 15:14:50 GMT

So the examples\peripheral\uart actually works fine with or without NRFX_URTE0_ENABLED. I can copy chunks of text in as fast as I like.

The issue is that I'm trying to get both uarts to work, as per instructions here: https://devzone.nordicsemi.com/f/nordic-q-a/25173/nrf52840-uart1-not-working-in-sdk-14/99170#99170

Using the serial example was the most simple reproduction of an issue I was having using that.

It looks like I can't use the uart module for that as it only supports one.

RE: nrf52840 serial

haakonsh — Tue, 07 Aug 2018 13:25:25 GMT

You should be able to build the sdk15\examples\peripheral\uart example with UARTE enabled by setting NRFX_URTE0_ENABLED = 1 in sdk_config.h If not there is most likely something wrong in your build configuration.

RE: nrf52840 serial

mtfurlan_t — Wed, 01 Aug 2018 19:37:58 GMT

I have a partially working uarte example now, it can print, but nrfx_uarte_rx_ready always returns false.

I stripped out all of the legacy layer that I could, and spent quite some time fighting with what turned out to be integration/nrfx/legacy/apply_old_config.h which will redefine things like NRFX_UARTE_ENABLED unless the legacy UART stuff is also enabled.

main.c: http://ix.io/1iWl
sdk_config.h: http://ix.io/1iWm

RE: nrf52840 serial

mtfurlan_t — Tue, 31 Jul 2018 15:33:44 GMT

Sorry on the delay in getting back to you, other projects took priority for a bit.

Could I just disable USBD? I don't need the virtual COM over USB for this application. Alternately, if I could get it to work with only the virtual COM that would be acceptable as well, but I will need a UART on the board to talk to an NMEA GNSS module.

Looks like nrf_usbd_disable should disable it, but doesn't change the issue.

Could you provide an example for UART with EasyDMA? I spent a day or so trying to get that working, but didn't manage to make it compile.

RE: nrf52840 serial

haakonsh — Mon, 16 Jul 2018 16:15:40 GMT

I think you might have a conflict with the USBD driver who disables interrupts for short periods of times before a transfer.

If this is the case then you need to use UART with EasyDMA in order to be able to R/W via UART in a period of time that wont get "interrupted" by the USBD driver.
Once the DMA buffers are loaded then you can process process the content whenever the CPU is available.

RE: nrf52840 serial

mtfurlan_t — Mon, 16 Jul 2018 12:45:54 GMT

So from what I know, if you use RX_PIN_NUMBER, TX_PIN_NUMBER, you can use either the pins or the virual COM port over USB.

With NRF_UART_HWFC_ENABLED, it doesn't work with the virtual com port, with NRF_UART_HWFC_DISABLED, the virutal com port works.

I did the above testing with NRF_UART_HWFC_ENABLED, and UART over the actual pins.

RE: nrf52840 serial

haakonsh — Mon, 16 Jul 2018 12:42:18 GMT

I'm a bit confused, are you using a virtual COM port over USB or the actual UART peripheral, or both?