Programming nRF52 chip using 2 UART pins

[Akshay]

hi

I have designed a small PCB with the NRF52 chip on it and kept few ports for some peripherals. Apart from that I only have 4 pins that I can connect to, UART-Tx, UART-Rx, Power and Gnd. I want to use UART for dumping code on the controller. Now I know that the code can be dumped on the controller using UART but I have never done that and I have very little experience with it. I also have the Blackmagic debugger which can be used as jTAG. I tried finding some useful resource which would help me get going but couldn't really find anything helpful.
I would really appreciate if someone can guide me with this or refer me to any resources online or on this forum which I might have missed, which might help me do the above task. Any tips or suggestion are appreciated as well. I hope I explained my problem properly. Thanks

edit - It has pre-flashed bootloader on it. I just want to put my application code on it now through UART pins.

[endnode]

Hi,

nRF5x chips don't have any ROM bootloader (unlike some other ARM Cortex-M chips from vendors like STMicro) so you need to flash the chip at least once over JTAG/SWD. You can develop your custom "bootloader" which can use UART for FW upload and then bootloads the chip through MBR (or other mechanisms if you don't use SoftDevice) but there is no example as far as I know.

Good luck! Jan

[Wojtek]

I think there is experimental secure bootloader over uart example in newest (v13) SDK. However, as you said - it has to be pre-flashed. nRF5x is not arduino :D

[endnode]

You are right, there is an example in SDK V13 now! Thx

[Akshay]

Sorry I forgot to mention but yes, It has pre-flashed bootloader on it.

[endnode]

Well if you have any custom bootloader pre-loaded you need to contact/get guidelines from the party which developed it for you. Hard to advice how to use something what we have never seen;)