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Powering Pixy?

OK, I know that it’s not a good idea to power Pixy (with servos) over Arduino connection. And, using an external power supply through power input is recommended.

My question is, does it make any harm to connect Pixy via USB while it’s being connected to an Arduino board which is also connected via USB?

In other words, Pixy is connected to Arduino via provided cable and at the same time, Pixy and Arduino are connected with different USB cables to different USB ports of a computer.

Thanks,

Ah, good question. I’ve done this and it bothers the part of my brain that’s always looking out for sources of noise — it’s a big ol’ ground loop. I’ve never had any problems with it though. If I were running the RC servos it might cause some extra noise on the power, which is never good, but I’ve never seen any noticeable effects here either.

I wouldn’t worry too much about it, esp if you don’t notice any noise effects.

thanks!

On a similar note, can I power the pixy through the “unregulated” JP1 connection and still interface with pixy via USB? The reason that I ask is that I am worried that my Raspberry Pi is not providing enough juice via usb to support the pan/tilt servos.I think this may be why my raspberry pi crashes when I run pixymon with servos attached to the pixy.

You can do this— if you’re powering through JP1, Pixy will sense and turn off a FET so you’re getting all your power through JP1 and not through USB.

thanks!

Perfect! My brother looked at the schematic and had this to say too: “You should be fine with the USB and the JP1. Both sources are 5V, so any fluctuation by either will only cause a tiny bit of noise and shouldn’t be enough to cause any real current flow from one to the other. In the worst case where something goes terribly wrong with your wall supply (e.g. short), there is a series diode on that input so no current can be pulled through the camera to damage it. Very worst case you just have to extinguish the flames coming from your wall supply.”