Before I make the attempt I was wondering if anyone knew if it would be ok to hookup a 4AA battery holder with 4 alkaline AA’s to the unregulated 6v of pixy to power it and the servos. I would then run the arduino cable from pixy to the arduino for power. I just wanted to make sure this won’t blow up pixy or something. I’m building an autonomous robot and can’t have a USB cable or ac adapter involved. Thank you very much for the help.
Hi Jim,
This should work fine. The regulator on Pixy can handle up to 1.0A, so just keep that in mind.
thanks!
Hi Rich,
Thank you so much for such a quick response. Is running the pan/tilt demo from arduino as simple as loading the code into arduino and then having the arduino hooked up to pixy thru the arduino cable? Is this all I need to do besides having servos plugged into pixy and my power in the unregulated part of pixy? Thank you so much for the help!
Jim
@ Rich LeGrand
I have noticed that 4xAA (6v) batteries don’t seem to have the current capacity to run the servos on my setup (using the pan & tilt kit)… Pixy just cranks to the upper right and stays there, and video output is very noisy. But if I switched to 4xD (6v) then everything works fine. I didn’t have a case for 4xC batteries, but should work as well, capacity wise.
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Thank you very much for the information and the picture Gunner! That is great to know and I will give that a try.
The C and D cells have lower resistance and this may be what’s going on. AA cells have enough current to supply Pixy and pan/tilt servos— it’s a voltage thing. You need at least 5.8V measured at the unregulated connector to be safe.
4 alkaline cells is sort of tempting things— I’d go with at least 5 cells to get the voltage higher. With 4 cells, all it takes is about .5V drop (because of current draw, battery resistance) and Pixy is having trouble getting 5V out of the regulator.
Thanks Rich, I had forgotten about the battery resistance of AA batteries. One would think that higher voltage would compensate, however, even with a 6xAA 9v setup I was unable to get Pixy w/P&T to respond… just cranks up and right and sits there pouting with noisy video 
Current carrying capacity seems to be the answer. I have tested with one servo at a time, and can get things to work, even with USB and AA batteries, but never with both servos and AA or USB option. The exception being when I used an older APC LiPo USB battery pack I have, with 5v @ 1.5A output… it seemed to work fine and makes for a nice portable setup to experiment with. PortaPixy
It is unfortunate that the max unregulated voltage allowance is only 10v… I usually run my robots off a small 12v AGM battery, and even my bench supply is either 5v or 12v.
Is this upper limit due to lack of heatsink or the actual limit of the regulator?
That USB power supply is exactly what I need to try. Will 5v 500ma work? Or should I go with 5v 1A?
The typical PC powered USB port supplies 5v 500mA… and (with the right quality & length USB cable) 500mA supposedly works just fine.
That said, I would go with the 5v 1A+ source so that your not stressing out either the supply or the Pixy/servos. The more amperage available the better… the Pixy (or any electronic device) will only draw the current it needs, regardless of the power sources amp capacity. It is the servos that will draw the most amps, and reportedly the Pixy can source (handle) 1A through to the servos, so as long as you don’t try to drive large servos the Pixy will not get overloaded.
Now if the designers wish to chip in and point out any errors in my statement, please do I am always looking to learn!
The 5v 1A sounds good to me. It sounded like the camera could handle the 1A limit through the unregulated input so hopefully the same is true for USB. I’m running micro servos and my big question was powering Pixy the same way it gets power from the computer. Last thing I want to do is burn the camera up with too much or too little current or amperage. Thanks again Gunner!
12v option would have been good for me also, pity it stops at 10v.
And for future reference…
What would you do if you did want to run bigger servo’s?
I would modify the servo wires, redirecting the power and ground direct to the power source (typically 5v-7.2v). One could even use separate power for the servos as long as both power sources share the same ground.
The signal wire (white or yellow) stays plugged into the Pixy… This direct to power wiring is common way to run many or large servos off of an Arduino, as it also is limited in how much current it can directly source.
Hi Cee Jay,
Use 3 diodes (in series) to drop the voltage down to 10V! (you’ll be wasting the power in heat anyway! Just be sure to point them in the right direction! haha… Seriously, this is a good trick. You can drop as much voltage as you like this way… I can suggest part numbers if you need more info.)
Regarding power and bigger servos— the rule of thumb is that you don’t want to sink more than 800mA (total) steady state through the servos (and Pixy’s regulator), and you don’t want to sink more than 1300mA peak (total).
If your servos need more current, Gunner’s suggestion is great — thanks!
Thanks for all of the suggestions for unregulated power.
I am an RC guy, so I was wondering if something like this would work:
(http://www.hobbyking.com/hobbyking/store/_28648__Turnigy_nano_tech_180mah_2S_25_40C_Lipo_Pack_US_Warehouse.html)
It is 2 cell Lipo that will put out around 7.4V. Also, I think the stock connector is compatible with the Pixy.
Thanks again,
Thomas
Hello Thomas, That battery should work just fine, although I might suggest a bit higher mAH rating for longevity. The RED discharge plug looks be a 2.50 mm (0.098 in) JST-RCY, BEC or P connector (got to love sorta standards), and I have successfully tested a similar battery on my Pixy with no problems… just be VERY careful to get the polarity correct!! as you can plug it either way. When looking at the back of the pixy, the positive pin is on the right.
Thanks!
And yes, I already learned my lesson about polarity during my undergrad, when I burned up an expensive MET station. The wires on that device were both black. 
One slight issue I have noticed, is that due to the batterys higher discharge ratings, the wires may be heavy enough (aka not as flexible) to interfere with the tilt movement as there is not much clearance when using the Pixy made pan and tilt stand.
The current into Pixy is still small, so you don’t need thick wires— trying replacing the wires with thinner gauge.
The current into Pixy is still small, so you don’t need thick wires— trying replacing the wires with thinner gauge.