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Unread 01-13-2013, 07:22 PM
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Powering the Raspberry Pi

For those of you with experience, how would you power the Raspberry Pi on your robot?

For those without experience, it is a small, cheap computer that runs on a microUSB cable, drawing 700mA @ 5V.

We need to power a camera as well, which is currently using the 5V port at the bottom of the PD board. Can we just splice the Raspberry Pi on?
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Unread 01-13-2013, 07:57 PM
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Re: Powering the Raspberry Pi

I'd use the 12v-5v converter to power the unit. The converter gives 5A, more than enough to run the Pi. The port on the distribution board gives out 3A, but with the camera on it, you have less than an amp left over. I've been running Pi's for awhile, they want a rock solid 5 volts, and 800ma to do high levels of computation, like video routines.
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Unread 01-13-2013, 10:20 PM
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Re: Powering the Raspberry Pi

I would be careful interfacing with the RPi, though. Micro usb powers the board with 5V in, but voltage drops to 3.3V and most of the chips on the board are regulated at 3.3V. In/out pins are unprotected, meaning that if you put a 5V signal on a pin, you might fry the pin.
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Unread 01-13-2013, 11:05 PM
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Re: Powering the Raspberry Pi

I'd just hook it up as a custom circuit.

Consider... you've got all sorts of 12V power available on the power distribution board. Throw a 20A breaker into one of those ports and get a "car charger" for a cell phone and you're done.

Consider that the 12V from your robot isn't any different from the 12V from your car's cigarette lighter. (Err... sorry... that's "power port" these days, thank goodness.)

Jason
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Unread 01-14-2013, 12:41 AM
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Re: Powering the Raspberry Pi

We are using Raspberry Pi's for our vision processing. To power them I made a custom power supply PCB with USB connectors to power up to 5 RPi's. If you want I can send you the files for it.
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Unread 01-14-2013, 05:48 AM
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Re: Powering the Raspberry Pi

Quote:
Originally Posted by Foster View Post
I'd use the 12v-5v converter to power the unit. The converter gives 5A, more than enough to run the Pi. The port on the distribution board gives out 3A, but with the camera on it, you have less than an amp left over. I've been running Pi's for awhile, they want a rock solid 5 volts, and 800ma to do high levels of computation, like video routines.
Won't the 5V converter already be powering the D-Link? Or can it provide for both?

Quote:
Originally Posted by Mr_smith View Post
I would be careful interfacing with the RPi, though. Micro usb powers the board with 5V in, but voltage drops to 3.3V and most of the chips on the board are regulated at 3.3V. In/out pins are unprotected, meaning that if you put a 5V signal on a pin, you might fry the pin.
We're only using power and ethernet. But I'll keep that in mind.

Quote:
Originally Posted by Kyle R View Post
We are using Raspberry Pi's for our vision processing. To power them I made a custom power supply PCB with USB connectors to power up to 5 RPi's. If you want I can send you the files for it.
We don't have equipment to build PCBs Are they commercially available?
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Unread 01-14-2013, 08:51 AM
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Re: Powering the Raspberry Pi

Quote:
Won't the 5V converter already be powering the D-Link? Or can it provide for both?
Sorry, I was trying to say use the 12->5v converter that AndyMark sells. It's inexpensive, has amperage capacity, mounting holes, and lets you put the converter on it's own breaker. Then there is never any question about power to the Raspberry Pi. It's also not a cheaply made part, it will stand up to the banging around that a robot takes during the season.
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Unread 01-19-2013, 07:20 AM
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Re: Powering the Raspberry Pi

Awesome!

Turns out it has more than enough amperage for the network adapter and the Raspberry Pi. But the darn rules say that the raspberry pi cannot share the same power converter.

EDIT: It says that the no other load may be connected to the terminal at the bottom. Does this refer to the wireless bridge (which I assumed) or the 12v-5v power converter (which means anything could be attached to its 5v terminals)?

Last edited by ohrly? : 01-19-2013 at 07:27 AM.
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Unread 01-19-2013, 09:23 AM
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Re: Powering the Raspberry Pi

I believe they are saying to buy another converter and simply connect it like you would anything else to the distribution board under a 20amp breaker.
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