libuarte: Connection between NRF9160dk and NRF52840

[Brett]

Hi,

If there is already a FAQ, Code or support ticket that I missed, I am more than happy to read it.  I have done a number of searches but cant quite get to what I am looking for.

Setup:
I am trying to get communications between the52840 and 9160 on the 9160DK, using libuarte.  I am using zephyr on the 9160 side an the  nrf-sdk on the 52840 side (as I need ANT+).

A few articles I read were using uart1 for this type of communications, so I cut/paste what was in there.  From what I could gather, a way to do this was to use the MCU_IF with pins 17/18 (9160) => 17/20 (52840)

9160 (.overlay file):

&uart1 {

compatible = "nordic,nrf-uarte";

status = "okay";

current-speed = <115200>;

hw-flow-control;

rx-pin = <17>; /* <&interface_to_nrf52840 0 0>; */

tx-pin = <18>; /* <&interface_to_nrf52840 1 0>; */

cts-pin = <19>; /* <&interface_to_nrf52840 2 0>; */

rts-pin = <21>; /* <&interface_to_nrf52840 3 0>; */

};

9160 (main.c)

Device binding is to UART_1:

struct device *uart = device_get_binding("UART_1");

52840 (main.c)

nrf_libuarte_async_config_t nrf_libuarte_async_config = {
        .tx_pin = 17,
        .rx_pin = 20,
        .baudrate = NRF_UARTE_BAUDRATE_115200,
        .parity = NRF_UARTE_PARITY_EXCLUDED,
        .hwfc = NRF_UARTE_HWFC_DISABLED,
        .timeout_us = 100,
        .int_prio = APP_IRQ_PRIORITY_LOW};

Question:

I can get all of this to work (or appears to) when I;
* start the 9160
* move sw to nRF52
* build->debug from SES
 -> click the green run button

* This appears to do everything correctly, receives ANT+, transmits from 52840 to 9160 and I can see it display on the 9160 tty port (using screen).

If I do it any other way, its as if the code on the 52840 is not running, or there is a problem with the connection or a timing issue ?

I added a nrf_delay_ms(5000) at the start of the 52840 code, just in case there was a timing issue between the 9160 and 52840 in that the UART was not ready - but that didnt work.

What am I missing here ?
I feel I have done every possible combination of switches, power and reset, but the only way I can get it to work is if I use SES Build->Debug 

thanks in advance

-brett

[Brett]

Hi Vidar,

It worked on the nrf9160df_nrf9160, and after I copied the overlay to nrf9160dk_nrf9160ns.overlay it works as well.  (note: I used nrf9160dk_nrf9160ns and not nrf9160dk_nrf9160_ns).

I will work from this to see if I can work out what the differences are.

cheers

-brett

[Brett]

Hi Vidar,

Your code by itself works fine, so I have tried to identify any differences between them.

Both lots of settings basically the same now (not identical as I have softdevice/ANT+ code) and the same thing happens, I can run the code in SES-Debug mode and all works, but as soon as I just run or power cycle the unit, I dont get the data through.

Q: I am using the s340 soft device, doest that influence the clock or timers I need to use ?

Q: Does the SES debug provide clock differently than not using it ?

The obvious difference I have between the 2 code bases is below, hence the reason for my timer/RTC question.

Mine:

NRF_LIBUARTE_ASYNC_DEFINE(libuarte, 0, 1, 2, NRF_LIBUARTE_PERIPHERAL_NOT_USED, 255, 4);

Yours:

NRF_LIBUARTE_ASYNC_DEFINE(libuarte, 0, 0, 0, NRF_LIBUARTE_PERIPHERAL_NOT_USED, 255, 3);

cheers

-brett

[Vidar Berg]

Hi Brett,

Your configuration looks fine. You have to select TIMER1  like you did as TIMER0 is reserved to the Softdevice.

Brett said:

Q: I am using the s340 soft device, doest that influence the clock or timers I need to use ?

The only difference is that you can't use TIMER0 like mentioned above.

Brett said:

Q: Does the SES debug provide clock differently than not using it ?

The HF clock is kept always on while in debug mode, but you will get the same effect by calling sd_clock_hfclk_request()  like I suggested in my initial reply. So I don't think the issue is clock related.

Have you enabled flow control on the 52840 side like I did in my example? I noticed you only had it on the 9160 in the initial code you posted. In that case, do you get a "busy" error if you try to send data from the 9160?

Cheers,

Vidar

[Brett]

Hi Vidar,

For now I am only trying to send data from the 52840 to the 9160 - so the flow-control should not be an issue ?

I have attached the code that I have, if you are able to try this on your board to see if it works for you, and/or if there is something obvious I have missed.

Note; This code is a cut/paste from one of the BLE examples which I have not completely cleaned up yet.
This code has also been cut down to send `1` every 5 seconds over the UART connection, so your 9160 receiver should be able to get the message and log it.

cheers

-brett

app_libUARTE.tar.gz

[Vidar Berg]

Hi Brett,

I have to spend some more time on this, unfortunately. I realized that my UART implementation on the 9160 isn't working properly either when I started testing with your example. Will try to get you an update tomorrow.

Cheers,

Vidar