How to program an nRF51822 using SWDIO/CLK?

[Oliver]

Hej,

that might sound like a dumb question, but what is the minimal setup to program an nRF51822 SoC using the SWDIO/CLK ports?

1. What external hardware is required?
2. What software is required to built and flash a new firmware?
   • What about the mbed SDK? Can I use it with a minimal setup?

I'm essentially looking for a minimal setup, which allows me to power and flash an nRF51822 based installation.

Sincerely, Oliver

[Charles Manning]

Well it all comes down to what you mean by minimal: minimal effort or minimal cost/hardware.

I'm using an NRF51822 as a supervisory micro + BTLE link for a system with the main application processor running Linux.

I use two GPIO lines to hook up to the NRF51822 SWD lines which is how the NRF firmware is loaded/updated.

This link implements the ARM SWD interface, which is a bit cryptic. This allows me to access all the address space of the NRF including being able to read/write GPIOs/ADCs etc and, of course, write the flash.

If you just want to get a low cost debugger going, then there are many examples on the web that use FTDI chips, eval boards or low-cost SWDs. eg. www.gniibe.org/.../diy-swd-debugger-ftdi2232.html

[Oliver]

I mean minimal in terms of hardware. Something like a "Hello World" for the nRF51822. A starting point I can use to do stuff, but not such a bloated DevKit. And for the programmer I just search something to buy (shouldn't be that expansive) which I can use in a plug'n'play fashion to flash my device. Something like the CC-Debugger for the nRF. I already have a minimal nRF device which I want to flash, but I'm also very interested in alternative devices.

[Charles Manning]

A further note on SWD code... I wrote my own because I had some special requirements, but there is a library called libswd (Google will find) which might do this for you.

[Charles Manning]

For minimal-in-terms-of hardware, it is hard to beat that FTDI solution.

[Oliver]

I mean for the nRF51822. Something like the minimal layout presented in the datasheet put on a tiny breakout board. For the programmer, and also for the chip, I would prefer an assembled and working unit. Hassle free, but minimal. Seems like I'm failing in getting my point across :/