Wednesday, 28 December 2016

Christmas console

Here is a rather agricultural console gaming machine I built for my three daughters at Christmas:



Emily is the youngest daughter, and thus the "Emstar" lighting at the top. The top box houses four speakers with the volume knob on the left front.

It kinda reminds me of what an iMac may have looked like if a caveman built an iMac with an axe when he was drunk. It's clearly not time to change profession; I'd better stick to my C++.

It's a Raspberry Pi 2 at the core as that's what I had sitting around. Retopie which is a debian based ARM linux image that includes Emulation Station was used for the base system. Retropie is rather nice as it includes a samba share straight out of the box, so that you can just drag and drop games to it from, depending on your poison, a smb://retropie or //RETROPIE path.

The box is mainly white with chromish trim to fit into the girls' decor.


The screen was from a broken Samsung 1920 x 1080 LCD monitor. The panel's touch control was extended and recessed into the side of the box, just in case. 

The only tricky piece was getting the sound to work off the raspberry pi. The output from the pi is a 4 ring VGSS 3.5 jack but getting a fair signal via hacking a 4 pole cable from the pi to my PAM8610 audio amp board proved a bit messy. So instead I hacked a 3 pole cable from the audio amp to the raspberry pi base which you can see here:

There are plenty of ground points, I chose PP6 for ground with PP25 and PP26 for the sound channels. A three amp 5.3V power pack was used for the pi and the brumby christmas tree LED pattern at the top of the box. That voltage is not quite within a modern USB spec but it worked OK with the pi 2. You can see here the direct solder attachment to pi jumper pins if you look closely enough:

I ripped apart some old speakers and took their main speakers and tweeters out, along with the crossover circuitry. A cheap PAM8610 amp cost $2.10 and this class D amp is supposed to be able to drive 2 x 10W but I have my doubts about that judging by the size of the heatsink on the chip though the chunky electrolytics and inductors on the crossovers may be helping there. It all seems to work without complaint.

Anyway, it may prove to be a fun project for your season break if you want to dig in. Though much of the build was driven by whatever was lying around, let me know if you'd like to see a more detailed build log with sources for parts, et cetera.

--Matt.

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