thingy52 (&nRF52840) writing my own software

[ToasTer86]

Hey Nordic Devzone,

I am really new to Nordic and am still a student in embedded software engineering. So first some background information.

I have 6x nRF52840 and 5x Thingy52. My goal is to create a mesh network using 5 thingy52's connected to a nRF52840. Than using thread/low6PAN to connect 2 nRF52840 and have one of the nRF52840 setup with a Wiznet5100 chip to post stuff to the internet.

Last few weeks were setup in to getting myself acquainted with the nRF52840 and got the Wiznet5100 chip working on a unit and can send HTTP GET & POST.

Back to the Thingy52: Right now I have Keil uVision installed and am able to compile (30 day license to bridge the 32k code limit) the code in : \thingy_sdk_v2.1.0\project\pca20020_s132 How do I get the .axf file on one of my Thingy52. If I am correct the Thingy52 does not support serial connection. So is it true that I have to use some cable to connect it to my nRF52840 to upload the program? Or can I do something else to get my program on the Thingy52? My goal is to get the Thingy52 connected with the nRF52840, any guides or tutorials available?

Another thing, the nRF52840 had some really good examples and documentation and getting started. I am kinda missing this with the Thingy52, I can only find documentation about the Android/iPhone app and the standard firmware/software the thingy52 is delivered with.

One note; the help has been awesome in this community and I want to thank all the people that have helped me in the last few weeks up front : Sigurd & Bjørn Kvaale

[Bjørn Kvaale]

First off, thanks for the kind words! I will mention to Sigurd that you have been pleased with the support you got from us. :)

If I were you, I would use Segger Embedded Studio (SES) instead of Keil from SDK 14 and onwards, as Keil is expensive and has the code limit that you mention (if you do not get the license). Not sure if you heard the news, but you can obtain a license for SES for free. You mentioned that the Thingy SDK does not have a folder labelled SES, so it works fine to use Keil.

Edit: Got a tip from a colleague here at Nordic: it seems what I said previously was not correct. Over the air DFU of custom FW can only be done if a key is generated first. Then you can compile the bootloader with your own generated key & flash the bootloader with an external debugger. Only then can you sign the custom FW with your own defined key & OTA DFU custom FW. It should be possible to use an open bootloader in the future sometime, but for now Nordic uses secure DFU in the Thingy:52. Here's a fantastic blog post that should be able to get you started!

When it comes to starting with secure DFU, you can do this via the SWD (edit: not JTAG) debug cable (attach your nrf52840 to usb, attach a SWD (edit: not JTAG) cable from the P19 port on the nrf52840 to the SWD (edit: not JTAG) connector on the Thingy).

[ToasTer86]

Was able to get a cable from the electronics department, was able to flash my boot_loader onto the unit know using the direct connection with a nRF52840-PDK. I also compiled the code in the project\pca20020_s132. With my own bootloader the Thingy52 just hangs in the DFU mode.

Seems this topic is about the same problem so I asked a question there to.

Because the cable is allowing me to flash and at least compile&upload the base code to the thingy52 I will start studying the mesh capabilities on the Thingy52. Although at this moment reading the library seems everything is BLE(4) with gap, gatt. Not the bluetooth 5 structure.

Can someone from Nordic tell me if the idea/project idea I had is even really remotely possible with the hardware I have now (6x nRF52840 PDK & 5x Thingy52) but most importantly with the software that is available for the thingy52 and the nRF52840. The idea I am referring to is: Mesh network of 5x Thingy52 & 1x nRF52840-PDK as host. Another network of multiple nRF52840-PDK using thread.