Attach an SPI sensor to the NRF51822 beacon?

[Andrei]

Hi, I intend to buy the NRF51822 beacon to use it to transmit data from an SPI-linked sensor. Is this feasible? (It seems so, but I just want to make sure). Also, will I be able to program the beacon to acquire and send data according to a schedule I choose or, for instance, to first fill in its RAM with sensor data and then to transmit all the data? Thanks, Andrei

[Håkon Alseth]

Hi,

It is possible, but it would be in the range of "electrically OK, mechanically unstable". You do not have proper pinout on the beacon board, so you have to solder into the test pads on the PCB, which again; is possible, but not recommended.

I would recommend obtaining the nRF51-DK instead. This kit is larger, but it also includes a debugger, proper pinout, and other features.

If you have a look at the blog-posts here, I believe I've seen a "logger" type BLE-application that another user has made.

Cheers, Håkon

[Andrei]

Hi Håkon,

Thanks for your reply.

I actually do intend to also buy the nRF51-DK, to be able to program/debug the beacon. However, my application is space-constrained and it's only the beacon that fits. Moreover, it has a battery holder that suits me fine.

On the beacon's PCB image I found on the web (developer.mbed.org/media/uploads/brarune/nrf51822_csp_coin-cell_board.png) I see there are several pads on the board: GND, VCC, CLK, IO, 0, 1, 2, 3, 5, 9, 11, 20, 21, 24. Maybe these are the test pads you mention. Why isn't it recommended to use them? I could use some of them to both attach a small (and light) board with my sensor(s) on it and also make the needed electrical connections. From the nRF51822 Product Specification (v3.1) I see that the chip has the remarkable flexibility of allowing to use any port pins for the SPI interface (and analog inputs as well). Ideally, the PCB layout would allow me to drill small holes through the pads, but I think it's OK for me to just attach to them by soldering.

Regards, Andrei