Creating a custom wireless device with nRF52832, what do I need hardware wise?

[RyanA]

Hello,

I am trying to build a small voltage stimulating probe for a research project I am doing. I was going to originally use the Rigado BMD-350 which includes the nRF52832, their own extra components and an antennae, but after finding they discontinued their old software and were suggesting to just use Nordics tools I decided to just create my own system with the nRF52832. I am struggling to find a few details though, does the nRF52832 come with its own antennae or does that need to be added (in order to use BLE)? Is there any other components or aspects I should consider when trying to design my nRF52832 based probe? And how does the nRF 52 DK fit into developing systems with the nRF52832 (can I hook up my chip to it and program through it or does it need to be soldered and programmed over SWD)? 

Thanks for any help,

[wpaul]

The nRF52832 is just a chip. It doesn't come with its own antenna, so you'll need to design one. In the case of Rigado, I think the antenna is basically just a copper trace on the PCB whose length and layout has been carefully chosen. (Disclaimer: I'm not an RF antenna design expert.)

The bare minimum for your design will be:

- the nRF52832 chip

- a copper trace on the board connected to the radio RF pin to act as an antenna (make it longer than you need for your prototypes and trim it to see where the sweet spot is)

- a 32MHz crystal (for the high frequency clock)

- a 32.768KHz crystal (for the low frequency clock)

- a 3.3V voltage regulator

- some capacitors to filter the power supply lines

- a way to flash the chip (ideally a 10-pin SWD connector wired to the SWD debug pins on the chip)

If you just purchase chips they will likely come with blank flash, which means you will need to connect an SWD debugger to the debug pins on the chip in order to load your initial software onto them. If it has a way to do firmware updates using another method (e.g. OTA) that's great, but the chips will be blank when you first get them.

Note that the nRF52832 does have an internal RC oscillator, and it's technically possible to use that as the clock source for both the high frequency clock and low frequency clock, but this is not recommended.

Note that you should be able to produce working projects with the Nordic SDK for the Rigado devices. The Rigado BMD modules basically just bundle the Nordic chip with a 32MHz crystal, the antenna, a metal shield and a few capacitors onto a board that's a little easier to mount to your own projects than using the nRF52 chip's footprint. You'd still need a power supply, external 32.768KHz crystal and (ideally) a debug port along with whatever else you decide to connect to the I/O pins.

-Bill

[RyanA]

Thank you for the information, what value is in the nRF52 DK though? Does it just emulate how your code would work on an nRF52 device? Also for this debug port, is that just soldering wires to the 2 SWD pins?

[Sigurd]

Hi,

RyanA said:

what value is in the nRF52 DK though?

What "value" are you referring to ?

RyanA said:

Does it just emulate how your code would work on an nRF52 device?

No, on the nRF52-DK there is a nRF52832 SoC. The code is running on the nRF52832 SoC, it's not "emulated".

RyanA said:

Also for this debug port, is that just soldering wires to the 2 SWD pins?

Yes. Also note that the nRF52832 need to be powered. And if you buy a nRF52832-DK it comes with a on-board Segger J-Link programmer/debugger.