PiPad

Photo 1 This is my version of the "PiPad." It may not have an elegant case, but it works, and it runs fast.

For a couple years I've been dragging a large monitor and a tangle of cables to my computer club to show off programs on the Raspberry Pi. After I saw an article in The MagPi about the official 7-inch touchscreen display, I started thinking about making a more portable Pi.

During a shopping trip at Micro Center, I noticed they had one of the touchscreen displays. I grabbed it and started looking for the other components I would need.

The Pi3 was on sale, so that was an easy decision. I expected to make something special for a portable power source, but a young salesguy pointed me at a rack of USB battery packs. You just plug 'em in. I also got a wireless mini keyboard with a trackball.

I downloaded a copy of the Jessie OS and assembled everything spread out on my desk. I expected something to go wrong, but lo and behold! It booted right up into the GUI. Even the touch screen worked.

Now I just had to show it off. All that was needed was some kind of enclosure. I thought an old-style lunch box would be ideal with its hinged lid, but then realized its metal would keep Wi-Fi signals out. I tried a wooden box from Michael's and a clear styrene box from The Container Store; but in the end, partly because it was the perfect size but mostly because I was in a hurry, I used the cardboard box that the display came in. It was easy to cut, had appropriate logos, and even had useful information about the display on the bottom.


Unfortunately not everything worked perfectly, and perhaps this is the justification for this write-up. Notice the little white square in the upper-right corner of the raytracer display. That's a rainbow icon that indicates the voltage dropped below 4.65, and the Pi has cut the processor speed in half to reduce power consumption.

The solution to this was: 1) use separate batteries for the RPi and for the display; 2) shorten the cables; and 3) because the rainbow icon would still appear occasionally, I bought new batteries from Costco. They deliver slightly higher voltage than my originals, and they come with significantly heavier gauge wires inside the cables.

Photo 2 Photo 3


Note the absence of the rainbow icon in the bottom photo. The chess program needs all the speed it can get to analyze millions of moves per turn.

Photo 4

-Loren Blaney