Is using an AAA battery connected to the TinkerKit inputs instead of connecting it to a PC, or Mac going to work with my Esplora Board?
An AAA battery?
Well..., put it this way:
A battery pack of AAAs would work - or of whichever cells you like is fine - provided that's not greater than "5V" (or not greater than VUSBMAX.)
How many would there have to be in the pack? Five? Six? Twenty?
Awesome_Guy:
How many would there have to be in the pack? Five? Six? Twenty?
Yes, right, twenty.
If we're talking about alkaline AA, AAA, C, D cells (batteries), they're 1.5V each.
NiMH, NiCd are 1.2V or so each.
What to do, which to use, depends on what's to be accomplished.
With a "boost converter" and two AA batteries, you can get a lot of run time (I have.)
Be sure that the battery (external power) is disconnected from the Esplora whenever you have the Esplora connected to the computer.
http://www.ebay.com/itm/121142828799
Does the Esplora have a regulator?/
No, no on-board regulator; the plan was for the esplora-folk to stay tethered to the USB, happy to do game controllers and so on.
Maybe some of the stuff onboard gets a down-regulated voltage, but the "5V" is all straight USB.
Probably 3 AA batteries would be good. There is probably a 3.3V regulator on board for some things as Runaway Pancake said, and it might not work correctly at 3V.
There's probably nobody keeping up, but I've been doing some work with this because I picked up a TFT.
The Esplora temp_sensor IC seems sensitive to "V_in".
My test for the TFT was the temp_sensor / thermometer sketch, something meaningful with no extra parts needed. I was using a lab supply set to 5V and then connected it to one of the little step-up converters I mentioned and my temp readings were about 4 degs F lower with it. (Incr. V_in → decr. temp reading). The step-up's O/P is 5.1V The temp_sensor IC runs from 5V directly.
I have, definitely, ohmmed the pins out and the USB 5V pin is 0_ohms to the Tinkerkit 5V pins (and Gnd is Gnd).
It's NOT the temp_sensor IC; it's stable. It's the ADC, its reference is "supply".
The electromotive force is the difference between the equilibrium electrode potentials of the two electrodes. Taking a lead-acid battery as an example, E=Ф+0-Ф-0+RT/F*In(αH2SO4/αH2O). (HHR-210AB18F4)
Where: E-electromotive force
Ф+0—positive standard electrode potential, which is 1.690V
Ф-0—Negative standard electrode potential, which is -0.356V
R—general gas constant, which is 8.314
T—temperature, related to the temperature at which the battery is placed
F—Faraday constant, the value is 96485
αH2SO4—the activity of sulfuric acid, related to the concentration of sulfuric acid
αH2O—the activity of water, related to the concentration of sulfuric acid
As can be seen from the above formula, the standard electromotive force of the lead-acid battery is 1.690-(-0.0.356)=2.046V, so the nominal voltage of the battery is 2V. The electromotive force of a lead-acid battery is related to temperature and sulfuric acid concentration.