Thingy:91 not connectable. LED is off but can program

[ImagiSam]

I was working with the Thingy:91 trying to get into into a serial printing state. I tried to updated the modem and firmware using the nrf Programmer. When updating the modem it hangs at 100%. Programming the device seems to succeed but now the LED is not flashing and the Thingy:91 is not connectable

I have tried downloading the following programs but it doesn't run:

• thingy91_ltem_2020-04-29_bc7ade8b.hex
• merged.hex (local based on 1.3.0)
• merged.hex (sourced from here https://devzone.nordicsemi.com/f/nordic-q-a/58484/thingy91-wont-boot-merged-hex-works-on-nrf9160-dk)

It seemed like it was working fine until the modem update which didn't work. 

The other thing is (once it starts working) that if I need to get it printing output to a serial terminal I need to flash:

• thingy91_ltem_2020-04-29_bc7ade8b.hex on the nrf91
• thingy91_nrf52_usb_uart_bridge_2020-04-29_bc7ade8b.hex on the nrf52

And I do that by flipping switch on device, then flip to other and flash and then it should run?

[Heidi]

Hi!

My initial question is: Are you using an external debugger or programming over USB? 

If you're using an external debugger, it looks like you're doing everything correctly, so I would be interested in the error message from the programmer application. If you're trying to program over USB using the bootloader, then it doesn't look like you're putting the device in serial recovery mode, which might be your issue. 

Best regards,

Heidi

[ImagiSam]

How do I put it into serial recovery mode? I have an external debugger as well. How can I differentiate between them in the programmer tool?

[ImagiSam]

So, I double checked what serial recovery mode meant and I am indeed doing that. It's not raising any errors and if I don't press SW3 and then turn it on then it tells me that I need to be in MCUBOOT mode. (I guess that's the same as serial recovery mode?)

[Heidi]

Hi, so if you are programming over USB, then we do have an issue with the Thingy v1.0.0 and Windows, that I want to let you know about.  If this is the combination you are using, flashing over USB will not work and I recommend you try using the external debugger you have on hand. 

You are also using the incorrect files for performing DFU over USB. You need to use the files in "images_dfu_hex", or when building yourself, select the file called "app_signed.hex", see the doc here.

[ImagiSam]

So, for flashing using the external debugger which in my case is the Nordic: nRF5340 If I connect to that board instead of the Thingy91 in programmer and program will it work or will I need to set anything specific up (it's connected through the 10 pin as expected)

I managed to get it to work. It seems that that was the problem I was using the full version. I wasn't able to find any thorough documentation about the different versions.

The next question is that I'd like to get the Thingy 91 printing to serial. Preferably without connecting to it in cloud but right now it doesn't seem to for some reason. I tried to use it out of the package and I tried: Programming usb_uart_bridge on the nrf52 then ltem on the nrf91 and then connecting to it in cloud:

I have connected to both ports. The first at 115200 and the second at 1000000 as specified in documentation.

To be clear what I'm trying to do is to get the Thingy91 to print sensor data to the serial so that I can use it as for 2 purposes:

• Data Collection tool, collecting accelerometer and environmental data
• Narrow down where I can add calls to an external AI library to make some predictions based on sensor data. To do this I'd like to add prints in different parts of the code