Its_All.Lost
Because hope just breeds everlasting misery…

The perfect Raspberry Pi enclosure

The perfect Raspberry Pi enclosure

There are many and I mean many Raspberry Pi cases out there. Fucking tons. There are a few great ones and a lot of mediocre ones. I came across a pretty good one. It is a great case and not just because it looks cool. It’s actually function-able. The case is designed to fit a VESA monitor mount. So if you have a TV or monitor on a stand you could bolt this to the rear and bam!. The holes are also great for general purpose mounting. The case is designed slightly different than all the others out there. There is NO CUTOUT for the micro USB power plug. We don’t use it here. This case has room for a DC-DC buck converter. Available on Amazon, eBay and all over. Standard part.

We take a nice big fat power source like 12v DC 3A and knock it down to 5.1v DC for the Pi. Then we wire that output directly to the Pies GPIO pins for 5v and GND. This works great, a nice fat stable power source. And the bricks are far easier to get a hold of then a 3A 5v USB plug. I have tons of them lying around.

DC-DC Buck Converter

 

We take the barrel plug and solder in a diode to the source side of the DC-DC buck converter. We take the output and apply that to the power GPIO pins for 5v and GND. Then we take a LED and wire in a 330ohm resistor and connect that to GND and GPIO 14 (UART TXD). Heres the trick to get the GPIO pin to follow the Pies power up and power down cycle. So the LED will turn off when the Pi is safe to unplug.

Edit your /boot/config.txt file and add the following line:

enable_uart=1

Thats it, now the LED will light when powered on and it will shutoff when it is safe to unplug the Pi. If you wish to use a different pin other than 14 you can follow this guide over here.

The case

Heres the thingy for my modified version of the case. The original calls for brass inserts for the screws, which is awesome I just don’t use them. So I remixed the files to use standard M3 screws. No more brass inserts. I also increased the depth of the lid. My jumper wires were hitting the top of the  lid and preventing me from closing it. No I have plenty of room fire wires and jumpers.

My Remixed Case

https://www.thingiverse.com/thing:2956874

Original Version

https://www.thingiverse.com/thing:2286741

 

PCDuino power

So yeah like the title says, the PCDuino seems to crave power when running a 2.5″ SATA hard drive. When using a SATA drive you need a 2.5AMP power supply, MINIMUM, or you will experience issues with the hard drive shutting down and disconnecting. With the PCDuino by itself a 2amp and 2.4amp supply seems to be ok. I was using an Apple iPad charger rated at 2.4amps, I use it on the Pies all the time with no issues, although I have read that others have some problems with them shutting down after a while (can’t find the link right now). I moved from the iPad charger to my Orico USB power supply (rated at 2.4amps each plug). It worked here ok but after 20 minutes the same issue appeared. So I pulled out the wall wart power supply that came with my CanaKit. Its a 2.5amp power supply that shipped with my RPi2. This power supply has been working flawlessly.

I tried two different 2.5″ drives with all of the power supplies I mentioned. One drive says 0.55amps the other 0.45amps both at 5v of course. They would both power up but after about 10-15 minutes the drives would start clicking, like they were losing power and cycling over again. Access to the drives was also lost while this happened. I tried three power supplies that were all rated 2.4-2.5amps. It seems they are not all created equal…

I need to get my hands on a USB current meter.

Side note: I purchased a BananaPi SATA hard drive cable kit off of Amazon for like $3. It will work – but you must SWITCH THE POWER AND GROUND CABLES! The BananaPi swaps the 5v and GND on the power cable. Just pull the pins out and switch them and it will work just fine. Or get a cable for the PCDuino or I head the Cubbieboard cable works too.