FEZ PANDA 2 Power Supply

NETMF & Gadgeteer
1

Guys sorry for such simple question but could you please clarify what external power supply should I use to power my PANDA 2 and not use USB as a power supplier? It says 6-9V but how much mA should be in that power supply?

Thanks!

2

Look here to see the power requirements:
http://www.tinyclr.com/compare/

3

@ Lurch - the Panda II is not up on the comparison page yet.

The brochure (a.k.a. user manual) doesn’t have specifics about max supply current/voltage. If we assume power usage is similar to the original Panda, we’re probably on the low side, since the board has more stuff.

Maybe one of the GHI “officials” can clarify or point us to documented power specifics? Now that more folks are getting these, I’m sure there will be a flurry of forum Qs…

4

Panda and panda II are 99.9% identical. The layout of the board was improved but everything else is the same.

5

Gus, if they’re almost identical why the power supply for PANDA should be 7-12V and for PANDA 2 6-9V?

Could you please clarify what power supply adapter should I use to feed my PANDA 2? How much mA should be there? For example there’re numerous adapters like
http://www.sparkfun.com/products/298
What characteristics I should pay attention to so it could suite my Panda 2 board?

Thanks

6

The regulators will take in 18V if I remember right but the heat will not be okay. At 12V either board will work fine but we realized that users always plug things in that draw more power so the 12V causes too much heat and stress on the regulator. This is why it was dropped to 9V

Here is the problem, a lower voltage will cause FEZ to reset if you cause power surge when running motors or when powering other electronics right from FEZ. On the other hand, a higher voltage will over heat the regulators, especially when you add devices that draw a lot of power, like Ethernet shield or FEZ Connect. So, a user will select an appropriate voltage based on what is connected to FEZ, not FEZ itself.

The power pack you pointed out should work fine in most cases unless you add a lot of things that draw power right from FEZ. In that case a 7V will help in reducing heat.

Now, do not worry about this too much. Regulators will heat up, this is normal and this is how they function but if the heat is to a point that you get a burn if you touch the regulator then that will be too much. And, the regulators have thermal protection so if they overheat then they will shutdown to cool down.

7

Gus, thanks a lot for such detailed explanation!