External battery for Pixel Qi display

[jlchulilla]

Hi,

I would like to know if it is possible to connect Pixel Qi Display with its controller to an external battery in order to use it outdoors. Ideally, this battery should also power a board such as Beagle or Rpi

Thanks in advance for the answers

[adafruit_support_bill]

It runs fro 5-24v, so one of our USB battery packs should power it: http://www.adafruit.com/products/1566
You will need to make an adapter cable from USB to a barrel connector. One of these will simplify that task: http://www.adafruit.com/products/369

[jlchulilla]

Thanks for the quick answer.

I'm not sure if the external battery that you quoted could power both a raspberry Pi AND a Pixel Qi display reliabily for several hours. Is that correct?

If it is the case, I am really interested in adquire the three elements

Besides, Do you offer a solar panel which could power both raspberry pi and Pixel Qi display?

[adafruit_support_bill]

That battery is 10,000 mAh (10 Ah) The Pi typically draws less that 1A (depending on what peripherals are attached). I haven't measured the current draw of the Qi, but we supply them with 9v/1A power supplies, so I expect they draw 1A or less. Assuming 2A for the pair, the pack should run it for 5 hours.

Powering direct from solar is not practical. A passing cloud could cause a 'brownout' and crash your system. You need to have some sort of battery storage for reserve. You would need to calculate your expected run-time vs the solar power available through the day, then design a system to collect and store that. All of our solar chargers are designed for lower-power systems and would not be able to keep up with a 2A demand.

[jlchulilla]

That's amazing!

I assume that the battery you mentioned would be enough for both pi and qi. Would it be too much if I ask you to test it?

I plan to use a pi with a p-qi display, an USB keyboard and maybe a BT mouse, all outdoors. I have been following pixel qi development for years, and I am strongly tempted. I would adquire it without hesitation if you positivelly assure me that such a battery would be enough for all the components, keyboard included.

I am not sure if a wifi dongle would surpass the 2A which offer each USB output of the external battery, added to the charge drawn by R Pi and the USB-powered keyboard.

After your advice about solar panel, I will opt for a working model with just the external battery

Thanks for all your answers and kindly attention

[adafruit_support_bill]

I don't have all the parts here to test. I will see if I can verify the current demands of the display.

[jlchulilla]

Thank you very much for such verification. It would be enough for me in order to buy all the components for mounting a DIY outdoor viewable laptop

I'm looking forward to hearing from you.

[adafruit]

http://www.adafruit.com/products/1303#Technical_Details has details for the HDMI driver + Qi screen

[jlchulilla]

Ok, I started from that page, but my technical level doesn't let me be sure by myself.

I would like to be sure about the powering schema of both RPi and display. Using a battery like your colleague pointed me out, I'm not sure if pixel qi display is going to draw energy from the Rpi board or independently.

Thanks in advance for the answers

[adafruit_support_bill]

The display is powered independently from the Pi. You can use the same power supply, but run separate cables to the two devices.

[jlchulilla]

Thank you once more. I hope that this discussion is useful for more people interested on outdoors use of pixel-qi and raspberry pi

I would like to understand the images that are include in your pixel qi's page




What is the purpose of little rectangular board below the display and the controller, connected with black, red and yellow cables? power the leds?

in the description of the product, it says that

We've packaged up this cool screen with a driver board and power supply. Since the screen is 3.3V LVDS, its very hard to connect directly to a microcomputer. The adapter board has a cable that plugs to the screen, there's a data line and a separate backlight line. (If you want to use the display in low-power backlight-less mode, simply disconnect that plug.

What would be in the photo that plug for negating the power to the leds and enable the backlight-less mode?

Thank you for your explanations and understanding. I want to build a portable solution, but I need to be sure of the major components and their function.

[adafruit]

the green mini PCB with buttons is the on-screen-display controller, it can adjust contrast, HDMI/VGA/AV in, etc. you cannot control backlight from it, the backlight is one of the red/black pair cables from the screen to the large blue driver board. you will have to switch the backlight with a transistor or a relay. we do not have a tutorial on how to do this, it sounds like you may want to hire an engineer to help you with this project since your "technical level doesn't let me be sure" and we do not offer consulting help.

[jlchulilla]

Ok, I'll try anyways, since it is not needed to develop a circuit or serious soldering. Now I have clear what does it need... and again, I hope that our dialogue will be useful for more users who want to build or mount their mobile solutions instead of buy an outrageus expensive and outdated netbook with p-q screen.

If you are interested, I can send you some advances about the project as soon as I can