Receive external data through UART on Thingy:91

RE: Receive external data through UART on Thingy:91

Håkon Alseth — Thu, 21 Nov 2019 12:00:19 GMT

[quote user="Marc__"]Thx for your answer. I did option 1 and it's working fine! :-) How the lines IF3-7 are used, i found in the nrf9160_pca20035_common.dts file. I just used an overlay file like this to my needed speed of uart1[/quote]

Glad to hear that you got things working!

[quote user="Marc__"]Thx for the general note, that CTS and RTS are not used anyhow.[/quote]

My apologies here, while the flow control (ie: the UART register setting) is enabled by "UART_0_NRF_FLOW_CONTROL=y" (change 0 to 1 or 2, if using UART1 / UART2), it seems that the nRF9160 sets the GPIOs as the respective output / input, with the default level set. Not a huge problem, but it reconfigures the GPIO pins, which could be problematic for some designs.

If you set the rts-pin = <0xFFFFFFFF>; and cts-pin = <0xFFFFFFFF>;, they should not be re-configured at all.

I'll report this as a bug internally

Kind regards,

Håkon

RE: Receive external data through UART on Thingy:91

Marc — Thu, 21 Nov 2019 06:35:00 GMT

Hi Hakon

Thx for your answer. I did option 1 and it's working fine! :-) How the lines IF3-7 are used, i found in the nrf9160_pca20035_common.dts file. I just used an overlay file like this to my needed speed of uart1

nrf9160_pca20035ns.overlay

&uart1 {
	current-speed = <115200>;
	status = "okay";
	tx-pin = <22>;
	rx-pin = <23>;
	rts-pin = <24>;
	cts-pin = <25>;
};

Thx for the general note, that CTS and RTS are not used anyhow.

I did not try option 2.

Marc

RE: Receive external data through UART on Thingy:91

Håkon Alseth — Wed, 20 Nov 2019 15:08:27 GMT

Hi Marc,

[quote user="Marc__"]For this I just need to know if and which two lines of IF3-7 would be available? Since the Modem Trace is not yet available (and I don't need it) I rekon I could use these lines. I want still to be able to see the debug log on the UART over USB however.[/quote]

If you cut the trace, and connect to the "nrf91" side, they're all available, as long as you have not enabled modem tracing.

As a generic note, the CTS and RTS are not used, so they're free to use even when both UARTs are running.

[quote user="Marc__"]Option 2:
TP7 is connected to P0.10 and has an already open solder bridge (SB5&6). Thus, It seems P0.10 is not used and I could use it for the UART_1 RX? One RX is the minimum I need. Or do you see another option for the TX line too? Maybe TP36 (P0.05) which seems not to be connected to the SPI:MISO?[/quote]

Yes, you're right wrt. P0.10. You can also hook into either SB5 or SB6 to get to P0.10. But, you are going to be short one GPIO here, as P0.05 goes to ADXL362 and ADXL372.

Kind regards,

Håkon

RE: Receive external data through UART on Thingy:91

Marc — Wed, 20 Nov 2019 07:28:47 GMT

Hi Hakon

I have the same need for an UART on the Thingy:91 like T1mS_. I have a SW running on the nRF91-DK communicating over UART_1 with an external controller. Now for the Proof of Concept I need to show a miniaturization for which I want to use the Thingy. I could think of two options:

Option 1:
Use two lines of the UART-USB bridge MCU_IF3-7 (P0.21-25), cut the according solder bridges (SB7-11) and connect the wires directly to one pad of the solder bridges.
For this I just need to know if and which two lines of IF3-7 would be available? Since the Modem Trace is not yet available (and I don't need it) I rekon I could use these lines. I want still to be able to see the debug log on the UART over USB however.

Option 2:
TP7 is connected to P0.10 and has an already open solder bridge (SB5&6). Thus, It seems P0.10 is not used and I could use it for the UART_1 RX? One RX is the minimum I need. Or do you see another option for the TX line too? Maybe TP36 (P0.05) which seems not to be connected to the SPI:MISO?

Thx!

Marc

RE: Receive external data through UART on Thingy:91

Håkon Alseth — Tue, 08 Oct 2019 10:24:34 GMT

Hi,

The Thingy:91 is limited in terms of GPIOs available.

The UART pins, marked with "MCU_IF0" to "MCU_IF7" are directly wired to the nRF52840, as the nRF52840 acts as a USB-to-UART bridge in this case.

If you need a more flexible solution in terms of GPIOs, I would recommend that you look at the nRF91-DK instead.

Kind regards,

Håkon

RE: Receive external data through UART on Thingy:91

T1mS_ — Tue, 08 Oct 2019 07:04:10 GMT

Thanks MJD093 ,

I'm going to wait for an answer from Nordic.

Your answer already helped me to get more in depth information. 🙂

Tim.

RE: Receive external data through UART on Thingy:91

MJD093 — Mon, 07 Oct 2019 15:01:37 GMT

The headers you have marked there are headers P6 and P7. They can be found on page 6 of the hardware pdf.

As for how to integrate with the Thingy:91, I will leave that question for Nordic as I don't honestly know how you would interface with it. I don't see any points for that.

I was just answering your original question you had on UART Pins and the code for enabling them 😅

RE: Receive external data through UART on Thingy:91

T1mS_ — Mon, 07 Oct 2019 14:15:05 GMT

Ok, I understand the TP stands for the test pads.

But I still can't figure it out which of the GPIO pins I can access. There are some free holes to solder pins on but they are not named:

RE: Receive external data through UART on Thingy:91

MJD093 — Mon, 07 Oct 2019 13:47:06 GMT

Hi Tim,

No, those are test pads. The test pads 18 and 19 are connected to the Power Management IC (see Thingy:91 hardware files, PCA20035_Schematic_And_PCB pdf, page 5).

RE: Receive external data through UART on Thingy:91

T1mS_ — Mon, 07 Oct 2019 12:08:14 GMT

Hi MJD093 ,

Thanks for the answer. So the Pins are set to 18 and 19:

Are these meant by this?

(https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.3.0%2Fble_sdk_app_cts_c.html&cp=5_0_4_2_2_7)

Thanks,

Tim

RE: Receive external data through UART on Thingy:91

MJD093 — Tue, 24 Sep 2019 15:57:19 GMT

Hi,

Any P0.## pin can be used as UART pins. You just need to set them up in the device's tree structure. The Perpiheral for UART# is given the P0.## pins that you set up in the .dts files and will configure them for you according to the configuration.

See https://github.com/NordicPlayground/fw-nrfconnect-zephyr/blob/a2c36f15843f9e11bd997cf5e72b0b4d69a552f7/boards/arm/nrf9160_pca10090/nrf9160_pca10090_common.dts#L83

The above link shows how this is done for the nRF9160 PCA10090 Development Kit.

In the device files for the PCA20035 (the Thingy:91) you just need to set up your desired pins for RX and TX like the above.

The default UART Pins on the Thingy91 are currently set as https://github.com/NordicPlayground/fw-nrfconnect-nrf/blob/b456fb40c4912e3d435b9ee029d8ef24b113f7d0/boards/arm/nrf9160_pca20035/nrf9160_pca20035_common.dts#L165