We have bad news and good news !

First the Bad.

We choose to use the Atmel SAM R21 to power the HaDge. It's one of the new breed of devices consisting of an ARM Cortex-M0 MCU + IEEE 802.15.4 Wireless radio bundled together. This was exciting since we could pack a lot of punch in the HaDge hardware. [Michele Perla] had earlier built a project called JACK – Just Another Cortex Kit – based on the Atmel SAM D21. This device was similar to the R21, but without the Radio. He decided to build a prototype R21 board based on the JACK design. This was the HACK – HackAday Cortex Kit. Building this would have allowed us to get it in the hands of the software team, while the hardware folks worked on the real HaDge layout. [Michele] finished the HACK layout some time ago, and we were looking for help with checking the Antenna design. We asked Atmel for help with verifying the layout. That's when we had the facepalm moment. They asked us - “What about FCC certification?” Since we plan to build the badges in quantities of a few hundred at the very least, it's obvious we cannot escape from FCC certification. A design based around the R21 is ruled out. We'll need to use an off-the-shelf radio module which is already FCC certified. Sigh.

Now the good news.

This is a setback in terms of time, and effort put in by [Michele]. But beyond that, we're good to go back to the drawing board and start afresh. First off, we decided to revert back to the Atmel D21. It's a fairly decent MCU, and being from Atmel, there's a fairly robust tool chain available that a lot of people are familiar with. For the Radio, we looked at some of these available options :

• https://www.anaren.com/air/products/24ghz-solutions
• http://www.nordicsemi.com/eng/Products/2.4GHz-RF
• https://www.adafruit.com/products/2471
• http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en535967

The last one from Microchip looks quite promising. But we're open for better and cheaper suggestions, so please chip in with your comments.