Thingy91 UART External communication

RE: Thingy91 UART External communication

Adeel — Thu, 17 Dec 2020 09:37:59 GMT

Hi Jonathan,

Yes, I got it working. The problem was not from the Thingy side, but from my sensor itself.

The P0.25 worked without effecting the link monitor :).

Regards,

Adeel.

RE: Thingy91 UART External communication

JONATHAN LL — Thu, 17 Dec 2020 09:34:46 GMT

Hi Adeel, sorry for the late reply,

Have you had any further progress?
It seems odd and i guess that there is no change in behaviour if you turn link monitor on or off. If you print out a arbitrary value over uart then it shows up fine and when you pas trough the sensor data then it changes somehow?

Regards,
Jonathan

RE: Thingy91 UART External communication

Adeel — Thu, 03 Dec 2020 14:29:17 GMT

Hi Jonathan,

Flow control is on in the link monitor.

Regards,

Adeel.

RE: Thingy91 UART External communication

JONATHAN LL — Thu, 03 Dec 2020 14:26:11 GMT

Hi,
Is flow control on or off in LTE Link Monitor?

Regards,
Jonathan

RE: Thingy91 UART External communication

Adeel — Thu, 03 Dec 2020 13:29:22 GMT

Hi Jonathan,

Thanks a lot, I did that and tested it. I actually did it to test another receiver pin.

I was trying to get an answer from my sensor on my Rx. I see the data on my receive pin and that data is correct. But when I try to read the data on my Link monitor, I get different hex values.

For example, I see (01 04 04 43 92 08 F6 C8 6B) on my receiver pin through my oscilloscope which is the correct data I need. But when I view the same on the link monitor, I see different values (79 FD F7 F7 EF 29 E0 E0 E0) and I see these values as well in my uart_buf when I debug the code. Its a very strange behavior I am noticing on my Thingy91 as I don't receive the correct bits when I view it, but the correct data is present on the pin when I measure through the oscilloscope.

For testing reasons, I changed my receiver pin now to P0.25 (previously it was P0.16) but the behavior is pretty much the same.

I had tested the same thing with the nRF9160DK before and it worked perfectly on the DK.

I wanted to know what could be the reason with the thingy91 and how can I debug it further ?

Regards,

Adeel.

RE: Thingy91 UART External communication

JONATHAN LL — Thu, 03 Dec 2020 12:08:48 GMT

After cutting SB11 one side is connected to the nrf9160 and the other is to the nrf52.

The right half of the pad is connected to nrf9160(Red highlight). Since you want to use talk to the nrf9160 you should connect the RX wire to the right side of the pad.

Regards,
Jonathan

RE: Thingy91 UART External communication

Adeel — Thu, 03 Dec 2020 10:40:54 GMT

Hi Jonathan,

Thanks for the answer, will do that. I will cut the solder bridge and try it.

I can connect the Rx wire to any one side of the SB11 pads rite ?

Regards,

Adeel.

RE: Thingy91 UART External communication

JONATHAN LL — Wed, 02 Dec 2020 16:00:09 GMT

Hi Adeel,

Cutting SB 11 should be fine, and it is always possible to revert the effect by soldering the two half's of the SB pad together.

Regards,
Jonathan

RE: Thingy91 UART External communication

Adeel — Wed, 02 Dec 2020 15:20:09 GMT

Hi Jonathan,

I tried using my Thingy91 for external uart communication.

It all went pretty well except for the receiver pin. Now, I wanted to use any of the pins from MCU_IF[4-7] to test the receiver input..

For that, I was looking to use MCU_IF[7] : P0.25 by cutting the SB11 and I have configured my UART 1 as follows now :

&uart1 {
	current-speed = <9600>; 
	status = "okay";
	tx-pin = <13>;
	rx-pin = <25>;
	rts-pin = <14>;
};

I just wanted to know if cutting the SB11 would have any have effect on my logging on the LTE Link monitor ?

Regards,

Adeel.

RE: Thingy91 UART External communication

Adeel — Mon, 16 Nov 2020 09:12:07 GMT

Hi Jonathan,

Oh okay, perfect. thanks for the info. I will try that as well :). Thanks for the information on this.

I will try it and let you know if I face any issues.

Regards,

Adeel.

RE: Thingy91 UART External communication

JONATHAN LL — Mon, 16 Nov 2020 09:01:03 GMT

Hi,

Cutting SB7 will make uart 0 not able to use flow control. you can get away with only rx and tx pin for uart 0, then in LTE Link monitor there is check box you can check to disable or enable flow control.

Regards,
Jonathan

RE: Thingy91 UART External communication

Adeel — Mon, 16 Nov 2020 08:54:08 GMT

Hi Jonathan,

Yes I understand that from the schematic.

I will try to use anything between MCU_IF [4-7] for my case then. Hopefully that wont affect my Link monitor.

I just need 1-2 more GPIO's for my use case so I am thinking about this.

Regards,

Adeel.

RE: Thingy91 UART External communication

JONATHAN LL — Mon, 16 Nov 2020 08:44:43 GMT

Hi Adeel,

If you keep The uart 0 pins then you will still have logging as normal.

&uart0 {
    compatible = "nordic,nrf-uarte";
    current-speed = <115200>;
    status = "okay";
    tx-pin = <18>;
    rx-pin = <19>;
    rts-pin = <20>;
    cts-pin = <21>; SB7, MCU_IF3
};

if you cut the SB7 then you lose the clear to send pin, you then have to configure logging a different way, and you want be able to use LTE link monitor.

Regards,
Jonathan

RE: Thingy91 UART External communication

Adeel — Fri, 13 Nov 2020 16:05:21 GMT

Hi Jonathan,

Thanks for this infomation, this can be done.

Just one last question before I am clear with this. Will my connection and logging to the LTE Link monitor be disabled if I try to use MCU_IF[] for external communication ? I think by default, UART_0 is for logging and viewing as seen in the autoconf.h file.

Regards,

Adeel.

RE: Thingy91 UART External communication

JONATHAN LL — Fri, 13 Nov 2020 13:07:43 GMT

Hi Alberto,

There is a switch SW2 that you can use to select between nrf91 and nrf52 on the thingy.

UART is not needed when using RTT. just make sure that the switch is locked in the nrf9160 position when you want to log RTT from nrf9160.

Regards,
Jonathan

RE: Thingy91 UART External communication

albdom — Fri, 13 Nov 2020 10:47:42 GMT

Hi!

I have the same problem, you can only use two instances of the UART on the nrf52840, UART0 and UART1.

My question... is the UART0 between nrf52840 and nrf9160 needed to log if it is wanted via RTT with the nrf9160DK connected?

Regards,
Alberto

RE: Thingy91 UART External communication

JONATHAN LL — Fri, 13 Nov 2020 10:40:47 GMT

Hi Adeel,

[quote user="Adeel"]Is there also UART_2 as was the case in nrf9160DK that I could use ?[/quote]

No, not on the thingy91 platform.

The Thingy 91 is not designed for developing additional sensor on and is more of a closed solution for testing systems and the onboard sensor. If you are looking for a small form factor solution the Icarus or Feather (more information here) solutions might be more relevant.

Since you have a nrf9160DK then you should be able to do logging over RTT, this way you can use more of the MCU_IF if needed but you need to have the nrf9160DK connected.

Regards,
Jonathan

RE: Thingy91 UART External communication

Adeel — Fri, 13 Nov 2020 09:31:17 GMT

Hi Jonathan,

I have a nrf9160DK and I am using that as an external debugger. I have used the same sensor and was able to communicate it with the nrf9160DK, but our main requirement is to use the Thingy91 platform for further development. That is why I was in need of more GPIO's.

Yes, for now I am using UART_1 by modifying the overlay file. Is there also UART_2 as was the case in nrf9160DK that I could use ? I can see only uart_0 and uart_1 in the dts file.

Regards,

Adeel.

RE: Thingy91 UART External communication

JONATHAN LL — Fri, 13 Nov 2020 09:02:39 GMT

Hi Adeel,

Do you have a eternal debugger? or do you plan to update the Thingy91 device with programmer app?

another thing, it seems that you are in need of GPIO's so i would highly recommend using a nrf9160DK instead of a Thingy for development and testing external sensors.

The MCU_IF pins are used to communicate between the nrf9160 and the nrf52840 is the interface that connects the nrf9160 to usb. If you start cutting the SB7 to SB11 you wont have full uart 0 and 1 support.

in the thingy91_nrf9160_common.dts file you can see that these pins are used to uart. if you can get away using only 1 then you can cut out uart1

&uart0 {
	compatible = "nordic,nrf-uarte";
	current-speed = <115200>;
	status = "okay";
	tx-pin = <18>;
	rx-pin = <19>;
	rts-pin = <20>;
	cts-pin = <21>;
};

&uart1 {
	current-speed = <1000000>;
	status = "okay";
	tx-pin = <22>;
	rx-pin = <23>;
	rts-pin = <24>;
	cts-pin = <25>;
};

If you cut all or any of the SB 7 to 11 then you will have to edit the board files also.

Regards,
Jonathan

RE: Thingy91 UART External communication

Adeel — Thu, 12 Nov 2020 12:43:19 GMT

Hi Jonathan,

Yes. I have taken that into account that the voltage should not exceed 1.8V which is what thingy91 GPIO's work with.

I was trying to look for more GPIO's that I could work directly with nrf9160. Are all the MCU_IF [0-7] used for modem tracing (or) can I use some pins of it without disabling the modem trace ?

Regards,

Adeel.

RE: Thingy91 UART External communication

JONATHAN LL — Thu, 12 Nov 2020 12:09:06 GMT

Hi Adeel,

Make sure that the voltage from the AST-3P does not exceed the voltage on the thingy91 capability's when connecting the two over RS-485.

Yeas that should be all.

Regards,
Jonathan

RE: Thingy91 UART External communication

Adeel — Wed, 11 Nov 2020 15:58:50 GMT

Hi,

I am connecting a AST-3P device that works on Modbus protocol. So, I require a RS-485 communication through UART , using Tx, Rx, RTS, CTS. I can pin up RTS/CTS together to 1 pin so I was looking for 3 pins that I could use directly for Tx, Rx, RTS/CTS.

To start off, I have configured this overlay file (thingy91_nrf9160ns) in my project.

&uart1 {
	current-speed = <9600>; 
	status = "okay";
	tx-pin = <13>;
	rx-pin = <16>;
	rts-pin = <10>;
};

I also changed the thingy91_nrf9160_common.dts file with the same pin configuration using uart_1.

Is this the only changes required to enable uart_1 in the thingy91 board ?

Regards,

Adeel.

RE: Thingy91 UART External communication

JONATHAN LL — Wed, 11 Nov 2020 15:29:01 GMT

Hi,

P6 is connected to nrf52840, to get to those pins you can communicate between nrf52840 and nrf9160. Setting up a passthrough on the nrf52840 where you get the UART from sensor to nrf52840, and UART from nrf52840 to nrf9160. Look at the connectivity bridge example for guidance on how to set it up.

[quote user="Adeel"]

That leaves me with only options of TP7 , TP32, TP33 for my uart.

[/quote]

Those are the only access points to a nrf9160 GPIO.

May i ask what sensor you are connecting since it is using UART and not i2c or spi?

Regards,
Jonathan

RE: Thingy91 UART External communication

Adeel — Wed, 11 Nov 2020 12:29:36 GMT

Hi Jonathan,

Thanks for the links. I referred to the hardware files and finalized the pins thereafter.

I have gone through the links you suggested me. I need modem tracing so I don't want to cut the solder bridges on MC_If[0-7]. That leaves me with only options of TP7 , TP32, TP33 for my uart.

Could yo verify whether these could be used seemlessly.

Further, could you let me know how I can use P6 pins (originally or nr52840) for nr9160 ?

Regards,

Adeel.

RE: Thingy91 UART External communication

JONATHAN LL — Wed, 11 Nov 2020 12:10:21 GMT

Hi Adeel,

Link to Thingy 91 Test points table. Most of the TP are in use or not really accessible and are there for testing and debugging or connected to sensors in use, in the link you can see all the listed test points and there use on the Thingy91.

Check out the following links for more information on previous attempts:
https://devzone.nordicsemi.com/f/nordic-q-a/52545/receive-external-data-through-uart-on-thingy-91
https://devzone.nordicsemi.com/f/nordic-q-a/51355/inputs-via-gpio-on-the-thingy-91

You can find more info in the hardware description of the Thingy91 and you can download the hardware files(Link to direct download) and including a pdf from our product page.

Regards,
Jonathan