Portable raspberry pi

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Techatron
 
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Portable raspberry pi

Post by Techatron »

I was just wondering if this setup would work.
Here is the battery I intend to use to power the setup:
http://www.adafruit.com/products/1566
Display:
http://www.adafruit.com/products/1928
Keyboard/Mouse:
https://www.adafruit.com/products/922
I also might use a wifi dongle. I was wondering if the battery would be able to power the screen/pi and the keyboard as well as the WiFi dongle workout any problems.
PS: I will be using the raspberry pi b+ Model

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adafruit_support_mike
 
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Re: Portable raspberry pi

Post by adafruit_support_mike »

Yeah, that power pack should be able to run a RasPi and a display at the same time.

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steverobey
 
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Re: Portable raspberry pi

Post by steverobey »

Is Adafruit going to make a similar power source at some point that we can use in portable projects? The Powerboost stuff is great but I've got to have more power captain!

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adafruit_support_mike
 
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Re: Portable raspberry pi

Post by adafruit_support_mike »

Check over at Pololu: http://www.pololu.com/

Their focus is on robotics, so they have a range of hardware designed for higher power levels.

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steverobey
 
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Re: Portable raspberry pi

Post by steverobey »

Check over at Pololu: http://www.pololu.com/
Why is it normal practice to send customers away when they ask about things like this?

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adafruit_support_mike
 
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Re: Portable raspberry pi

Post by adafruit_support_mike »

To be blunt, they care about it more than we do.

Our main range of interest lies in roughly the 5v @ 1A range. Handling voltages and currents higher than that takes specialized techniques if you want to do it well, and we aren't interested in devoting the kind of resources it would take to develop first-class solutions in that area.

Pololu's focus is on robotics, so they have a strong interest in building hardware for power levels beyond our main area of interest.

No matter where we draw our line someone will want more, so we'd rather send you to someone who cares about doing it right than try being all things to all people.

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steverobey
 
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Re: Portable raspberry pi

Post by steverobey »

I guess I should have been more specific, rather than more power as in higher voltage, I was more referring to amperage. Batteries that would last longer. I've found that the 500c with a 2500 mAh battery is sufficient to make my Raspberry Pi project portable and 100% wireless for a minimum of about two and a half hours of continuous use but is probably a bit more than that on a full, freshly charged battery. I did also note you provide a 3-cell lipo that is at 6600 mAh as it has three matched 2200 mAh 18650s which is great, I like what you've done there. What would be even better is a four cell version with 5000 mAh cells for a total of 20,000 mAh. that would be truly impressive. But I get why you have not done it. You guys have a lot of great products and you have a fairly wide range of things one could purchase and put together into a fine prototype. All of these things have been tested and proven to be good middle of the road solutions. I also have not had any luck at all finding 5000 mAh matched 18650s that aren't already sealed in an ugly little box with a gigantor USB port so it is likely I will have to design something myself.

I'm starting to understand why things the way they are. You're right, it makes more sense not to try to be everything to everybody, otherwise you would constantly be adding new things to your inventory from other companies and would probably be losing money in the deal. The unfortunate truth that I am learning is that there are just some instances where I'm just going to have to design things myself and order parts from China.

The parts available at Adafruit industries, I will consider a great jumping off point to help people learn a few things about this type of hardware in one or several relatively small purchases. You can in fact buy everything you need to start prototyping that micro computer idea in your head and learn a bit about the hardware you are using. From there, it's up to you to determine if that hardware suits your needs or if, like me, you've just got to have more.. amperage. Or a faster processor, or a bigger this or that.

The first kit I bought here was a mintyboost. I have soldered before so that wasn't anything new, but it was still interesting to see what could be done with a relatively small circuit. I quickly learned that it wasn't what I needed for my project and so I jumped up to the Powerboost 500c which has proven its worth to me, so I did learn. Obviously as far as this project goes, I suppose it is time I leave the nest. But I will be back and I have already pointed others here.

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adafruit_support_mike
 
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Re: Portable raspberry pi

Post by adafruit_support_mike »

Power is volts times amps, so if the votage stays the same, 'more current' equals 'more power'.

When you work in the 5A-10A range, you'll find that you have to start paying attention to the size and resistance of your wiring. You'll need to learn about heatsinks and thermal resistance calculations, and start balancing current versus signal duration to stay in the safe operating range of your active components. You'll have to start designing your ground path instead of just assuming GND means 0v everywhere, and you might have to start worrying about induced EMF between signal lines.

They're all learnable, but they fall under the heading of "having to care about first-order parasitic terms". It's a whole layer of knowledge you have to stack on top of the basics. Our goal is to be beginner-friendly, and part of that involves limiting the obvious ways to fail.. especially the ones that can go bad in ways that cause serious damage.

We're more willing to push the limits of signal generation and processing though. A ringing transmission line is annoying, but it won't burn down your house. You may find that the solutions offered by companies that handle higher power seem a bit chunky compared to the stuff we do here.

Find all the sources you can though, both for hardware and ideas. Only you can decide what kind of Maker you want to be, so assemble the collection of resources that do what you want.. that's the highest expression of the Maker mindset.

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steverobey
 
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Re: Portable raspberry pi

Post by steverobey »

I have a burning question I feel like I need to ask you..

Why is there a Powerboost 500c but no Powerboost 1000c?

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adafruit_support_mike
 
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Re: Portable raspberry pi

Post by adafruit_support_mike »

The boost converter takes its supply from the LiPo charger's output, and we haven't found a charger that can handle enough current for 1A @ 5v output reliably.

There are also some noise problems.. a LiPo charger watches the battery voltage to monitor the charging cycle, and boost converters are noisy. Think 'marching band drum line' meets 'stethoscope'. It's possible to filter the noise, but that gets harder as the current increases.

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steverobey
 
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Re: Portable raspberry pi

Post by steverobey »

There is definitely a high frequency but audible hum coming from my 500c but I did also find a thread here that went over a few different ways of isolating / filtering that away from sensitive equipment, so that will certainly be something I will want to sort out before I consider putting one in space, but it is still on my list as a possibly viable off the shelf answer. The other thing I need to consider there is the 90 minute charge / discharge cycle everything is going to experience traveling at ~17,000 mph, but now I'm getting way ahead of myself. For now I'm just going to focus on making something portable on the ground.

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steverobey
 
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Re: Portable raspberry pi

Post by steverobey »

Just to update, if anybody has plans to do anything similar to what I'm doing and isn't afraid to void their warranty. You can disable the things you don't need and bypass the Raspberry Pi's 5V regulator and run it on 3.3v. Keep in mind you will be doing this at your own risk. Also keep in mind the Raspberry Pi is inexpensive and readily available. It deserves to be hacked and made more useful than it's creators have engineered it to be. It is plausible to fly a raspberry pi. Check out this link.

http://www.daveakerman.com/?page_id=1294

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