Hope you are well,
I need some assistance as I am not too technical emended when it comes to power (Voltage, Wattage, Amperage etc....)
I have purchased, albeit a long time ago and still waiting for, the Kickstarter HDMIPI which will be being delivered relatively shortly. I have already started plans on making a small portable media centre (the main reason I purchased the screen) and trying to work out how to make a portable power source.
https://www.kickstarter.com/projects/69 ... the-raspbe
I have done some investigation and prelim work in what is required and started sourcing materials to mess around with to get something sorted before I receive the screen.
The information I have had around the power from Alex Eames of the HDMIPI team is as follows:
"The micro-USB input takes 5.2V, the 1.6mm barrel jack takes 12V. The screen needs 5 Watts and the Pi needs about 2-3 Watts. So at 5.2V you need an Amp for the screen and about 1/2 Amp for the Pi."
So the Driver board will power the screen and the PI via the 1.6mm Barrel Jack at 12V - I have a 64GB SSD drive I will be using for storage of media so this will need to be powered through the PI as well.
My thoughts on the Flow chart I imagine would be:
Batteries -> Buck Converter -> Driver Board -> HMDIPI Screen and Raspberry PI powering IR sensor for remote and 64GB SSD
With this information I have bought the following:
10 x 3.7V 6000 mAh Lithium Ion batteries (3.7V x 9 = 33.3V // 6000 x 9 = 54000 mAh)
http://www.ebay.co.uk/itm/261418209606? ... EBIDX%3AIT
1 x LM2596 DC-DC Switching Adjustable Voltage regulator Buck Converter to step down the 33.3V to 12V (Buck Converter operates up to 35V)
http://www.ebay.co.uk/itm/281218773432? ... EBIDX%3AIT
I need help in a few areas due to my lack of knowledge -
- Are my above calculations correct and will they theoretically supply the 12V to the driver board?
- Do I need to add a PCB for protection for the Lithium Ion?
- Is there a way to create a toggle to switch between a Barrel Jack with a 12V power supply to the internal batteries?
- Which way is best to wire the batteries? Parallel or series?
- Will this provide enough Amps?
Sorry if some of this may seem stupid to people but I have ideas and don't always have know how to execute, bit of an ambitious project for someone with limited knowledge in this area
Anyways if anyone has anything that can help, valid input, criticisms, ideas then please feel free to share them.
Hope to hear from you guys soon and many thanks in advance.