Adafruit Feather nRF52

This board appears to have the exact same Nordic module as Puck.js. Would we be able to get Espruino running on this board? What would it take (other than the flashing hardware).

I like the form factor of the Feather boards and the modularity between the various wings. But I always make sure to support Espruino by buying the official hardware as well. Long time backer of all the Kickstarters!

Yes, you should be able to. You could check the circuit diagram against the nRF52832DK, but if Adafruit have used the same pins for Serial RX and TX then you could use the existing nRF52832DK firmware for Espruino (http://www.espruino.com/binaries/travis/master/).

Having said that, they have their own bootloader by the look of it, so you'd have to look into how exactly that works. It might be that if you just uploaded the firmware (not the softdevice or bootloader) region then it'd 'just work'.

If you programmed it via an external SWD programmer then you'd be sorted though - just shove the nRF52832DK firmware on there and you're laughing.

I might have a word with them and see if we can arrange a way to get it on the Espruino site - if there's a custom firmware in a format that can be uploaded with their bootloader then it'd be much easier.

Just an FYI, I used the SWD pins and loaded the nrf52832 hex file and was indeed off to the races.

Hi @billsalt, could you explain to me what you used to load the nrf hex file and which the SWD pins are?

I used nrfjprog from the Nordic Semiconductor toolset using the Nordic Development Kit JTAG output. The SWD (SoftWare Debugger) pins are on the center connector X1 (loaded on the Pro version). Adafruit schematic: https://learn.adafruit.com/assets/52793.

Thank you! Haven't used any Nordic Dev toolkit before (just been married to all the Espruino devices to date).

@billsalt Is this the dev kit you are referring to?
http://au.element14.com/nordic-semiconductor/nrf52-dk/dev-kit-bluetooth-low-energy-soc/dp/2842319

Oh never mind I think I found the one ... on the Espruino site of course!

They all have JTAG output, though it isn't widely documented due to agreements with the Segger debugger. The nrf52-dk is a good choice, since it will natively run espruino as well.

I think it would be great if there was a way to collaborate with adafruit, this specific product they have , combined with espruino would be epic, it is nice to have the usb and battery charging integrated. The feather footprint would offer so many awesome accessories that they have developed for their feather line. I have a couple of the mdbt42q breakout boards from the espruino store and they are pretty cool, but I plan on trying a project with a nrf52 feather so i can try to make an easy, clean build using some feather "wings" as they call them.

It would be great - I have tried to suggest it to them at several points in the past, but I'm afraid there just doesn't seem to be the interest in it. The maintenance thing that some other companies (RuuviTag, Seeed, Nordic, etc) are doing would be perfect - I guess I could try and revisit it with them now it's a bit more popular.

@Gordon, do you recommend a particular SWD programmer that will work with the Nordic chips? I see some cheap ones out there, but not sure if I need to look for anything special to be able to work with the nRFs.

Honestly, I'd say buy an official nRF52832DK: https://www.nordicsemi.com/About-us/BuyOnline?search_token=nRF52-DK

I believe they're basically sold at cost price so you get quite a lot for your money. As well as all the proper segger dev tools they also just appear as a USB disk, so you can just copy the hex file on to flash the device - no software needed.

Otherwise if you want to go cheap you can use a Raspberry Pi and OpenOCD, but be prepared for a bit of messing around!