I'm in agreement over the problem with using croc clips.
Putting the VCC and GND in close proximity to each other, with some other conductive connector stripes in between, is IMHO asking for trouble.
Just having that much exposed copper is asking for trouble, Imagine kids sitting at tables each with one of these things running of a battery pack. How long would it be before 2 of them came into contact.
If it happens to be plugged into the USB when the VCC and GND are shorted, its going to take out the 3.3V regulator (I presume it must have one or do these NRF chips also run on 5V ?)
The other design issue is the micro USB connector, because they are only physically attached to the board via 2 small solder pads, and generally can not withstand much force being applied e.g. when attached to a thick / standard USB cable, or merely being over zealously plugged in.
I've had to repair several small boards which have this style of connector, by re-soldering the SM usb connections and then eposy'ing the whole connector down.
Re: Cost to UK tax payers
As far as I can tell, its unclear who is paying for what. Certainly some stuff is getting donated, but I don't know if the BBC has actually said the cost to the UK TV licence payers is zero.
BTW. There is a thread on Slashdot about this, with basically the similar sorts of responses, and also Wired
site and also comments on the various YouTube videos.
We already discussed the USB connector, it is not the weak type you are thinking of. From the video I think it is this type, with the 4 DIP legs:
http://www.digikey.co.uk/product-detail/en/10118194-0001LF/609-4618-1-ND/2785382 (there's a characteristic shape to the back legs which can be seen in the video).
It's really not a problem if some of these break. That's what real electronics do when you mess with them. Not often, but if you abuse them, they will, and that's a good learning experience too. Let's not smother children in some dull Fisherprice electronics plugboard please!
Cost to taxpayers, or license payers (not the same thing, I haven't paid for a tv license in more than 10 years since I don't care about watching live broadcasts)? Of course it's not going to be 0, if nothing else there is the time spent by BBC staff on coordinating and managing the project. But the multiplier from the donations in time and material from the participating companies means that the value obtained is enormous. And so what? This project is squarely in line with furthering multiple of the BBCs public purposes, such as "Promoting education and learning" and "Stimulating creativity and cultural excellence", and arguably a few of the others as well. If you choose the buy a TV license, then don't complain that the money is getting used in accordance with the agreement between the BBC and the country! I'd much rather it gets spent on a project like this, which no matter what you think about niggling details of the implementation is going to help at least some kids to develop or further an interest in programming, science or electronics, rather than another inane "reality tv show".
I'm frankly disappointed by the reaction in this forum and as you pointed out others. I know as engineers our first intuition when seeing a project is to see the little niggling details that don't conform with our own preferences for this or that, often well-founded and based in experience. But isn't that a little missing the forest for the trees?
Out of my friends in the computer and electronics industry in the UK, at least half developed their interest initially by programming on a BBC micro. Just imagine what the reaction to that project would have been on our forum when it was first announced!
In my view the BBC really lost their way for a long time in the 90s and 00s, and I think it's fantastic that they are spawning projects like this one again.