Pi in a Sega Genesis USB Hub Build

obsidianspider

@hansolo77 I made the headphone hole first. (I actually messed up and it's ~1.5mm too close to the corner) but since it sticks out farther, once that was cut I could mark where the HDMI plug was, then I filed each half separately. I'm going to try to explain how I made the two holes, but it's difficult to articulate so here goes:

With the case apart I set the Pi 3 in the bottom half and slid it up to where I'd want it to be, then I saw where the headphone plug was hitting the side of the case. With a pencil I drew marks on either side of the hole, so I knew where the outside edges were. Then I drew those lines to the outside of the case so I could see them when I put the top on.

With the case together I held the two halves together and drilled a small pilot hole in the middle of my two marks that denoted the edge of the headphone plug. I then took the case apart, slid the Pi in, saw it looked pretty lined up, then closed the case up to make another slightly larger hole.

After a second larger hole, going slowly (the two halves of the case kept wanting to separate) I took it apart again and put the Pi in and saw I was slightly off, but not terribly. Slightly bummed I continued, making the final 1/4" hole. It's not perfect because the case kept getting caught on the bit and separating, but it's ok.

I then took the case apart, slid the Pi up to the edge on the bottom half (the headphone plug now was able to poke through) and marked the outside of the HDMI port with pencil. Then I slowly filed it flat.

If you look at an HDMI port the bottom has a little dink in it where it's smaller than the top, so as I filed SLOWLY and rechecked I saw when the far top part was exposed then marked with pencil where the narrow bottom part was and then filed SLOWLY until the bottom narrower part was exposed. I cleaned up a little with an xacto knife and when I was happy with the HDMI port then I moved on to dremeling the Micro USB port flush, since I still don't trust myself to desolder SMT stuff in tight quarters. If you're going to attempt that, use a cutoff wheel and go as SLOWLY AS POSSIBLE on your variable speed on your Dremel. DON'T FORGET TO BLOW OUT THE METAL SHAVINGS. You don't want to short out the Pi with debris in the port or anywhere else.

For the top of the HDMI port it was basically like the bottom. With the Pi sitting in the case I marked the outside edges on the top and then filed inside the lines SLOWLY and checked constantly to try to keep things fairly even and to make sure I didn't go too far. You can always take more off, but you can't put the plastic back on.

Like I said, get some junk plastic to practice on. Even like an old sandwich container with a crack in it or an old switch cover or something you were going to throw out anyway.

Sorry for the rambling, hopefully that helped explain how I went about it.

hansolo77

Here's my DB9 cuts from earlier today. I just took this with my Samsung Galaxy Tab. Never did that before either. Cool. :)

http://imgur.com/jKRVDQi

Needs work.. :/ Like I said, if I can find some kind of rubber ring I can just slide over top of the outer edges of the plugs, it should be good enough to cover where I over cut. The hardest thing about this cut was that I had to do it 4 times. Twice for the black bezel, and then twice again for white bezel behind it. The black bit is just a screwed on cover, part of the NES case. So I cut the black one first, then outlined the inside on the white bit. Cut that, then spend forever trying to figure out why the plugs still wouldn't sit inside their holes. Turns out it was due to the spacing behind the white bezel, where it has some 90-degree angles for regedity, that was pulling the plugs further back. FInally got it figured out, but man, this is just a horrible job. :(

obsidianspider

@hansolo77 hey, they didn't make these things for us to repurpose, so it's going to take some figuring. I have a broken NES that I got from a friend back in college. I took it apart to try to fix it a few years ago and likely made it worse by trying to rebend the pigs on the 72-pin connector. Don't feel bad about making mistakes, it's how you learn.

hansolo77

Yeah I'm not that upset about it. Nobody's really going to see it. Sorry for hijacking your thread so much though. :)

obsidianspider

@hansolo77 yeah, sometimes I wish the forum had a DM feature, but I can also see it being abused where developers would be inundated with stuff. Oh well. I made these build threads to show how I'm making my projects, mistakes and all, to try to help others. Some just show off the end product, and that's fine, but I still largely have no clue what I'm doing, so if I can write up how I solved problems maybe that can help someone else learn too.

edmaul69

@obsidianspider if yo decide to add a usb audio aplifier you could make the volume slide work for a headphone jack with a 20mm slide potentiometer.

ebay link

cyperghost

@edmaul69 @obsidianspider
Come on use your fantasy :) You both inspire me to do stupid things :)
Set two switches on the volume slider and connect to GPIO :)
Then you should be able to raise and lower volume .... Is that a good idea?
If it does not work via ES then it works 100% with alsa sound mixer :)

edmaul69

@cyperghost if you can control the audio level through the gpio with this that would be awsome.

cyperghost

@edmaul69 That is easily possible!

# Gets a list of simple mixer controls
$ amixer scontrols 
Simple mixer control 'Master',0

then

amixer sset 'Master' 10%+

Raises mastervolume to 10% ingrements and you will just need a script that read out the GPIO to raise and the GPIO to lower volume.

EDIT:
Well I would use two springs, that center the slider. Then you hold it in + position and the script ask every 0,5 seconds the status of the GPIO and then raises volume +10%. Hold the slider in - position the script asks the status of the GPIO and lowers volume -10%

meyemind

With the power on/off switch, here is a solution I'm going to try for my build, thank you @obsidianspider , definitely following your progress to lead the way for mine!! (solder station arrives tomorrow :) The LED can go straight to the genesis hub, and I'll incorporate the switch as well.

Cheers,

alt text

cyperghost

@meyemind Does this fit in the case? I'm a bit concerned...
What is the difference between the powerblock and the mausberry?
Are these circuits a "must have" or more a "nice to have"?

Can we get them cheaper? :D

meyemind

@cyperghost I'm not sure how @obsidianspider was going to fold in the mausberry, but from what I can tell, yes the powerblock should fit just fine, I was confident enough to make purchase and will post a reply once I have it and can show that it fits.

meyemind

@cyperghost Regarding the "must have" vs "nice to have" hooking up the power switch on the genesis USB hub is definitely a "nice to have" option. The pi3's don't come with an on/off power switch, you would "sudo shutdown -h now" command line or via terminal to properly and safely shutdown the pi before pulling the plug. Furthermore all of the emulation OS options out there have GUI options to do this as well.

But putting in a switch is so much sexier... ;)

cyperghost

@meyemind Well I ask because you can do the shutdown just with a switch and some scripts. I would try to usw the circuit from @adamspc but the shopping costs are high...

Is there a way to geht the circuits cheaper?

meyemind

@cyperghost Sorry, which circuit from @adamspc are you talking about?

cyperghost

@meyemind http://othermod.com/product/advanced-onoff-board/

meyemind

@cyperghost Ya, nice one, if the soft on/off action is what your looking for. After a few quick searches on pi3 soft on/off... it pretty much returned a page with your link and this simple soft on/off one.

Looks like it's a custom board that unless you can find someone else who created an alternative soft on/off option for cheaper w/ $hipping, then that Advanced On/Off Board is your best bet. Keep us posted.

obsidianspider

@meyemind said in Pi in a Sega Genesis USB Hub Build:

@cyperghost I'm not sure how @obsidianspider was going to fold in the mausberry

With the 2-pin spring header board as a separate piece, I'm planning to have it sit next to the Pi board and connect the Mausberry via wires, not a plug. The Mausberry hasn't arrived yet, but once it does, don't worry, I'll post pictures of how it does, or doesn't work. Since I'm still looking for a power switch I may use a simple light switch flopping around on the outside of the case temporarily to control the Mauseberry.

cyperghost

@obsidianspider Yes I think the mausberry (spring version) is the best option. The board from petroblock seems to be a bigger in size ....

But the costs are high....
17$ + 5$ shipping is okay for mausberry
22$ + 5$ shipping for petroblock is okay :)
10$ + 20$ shipping for othermod is great (without shipping)

But how the circuits work?

The othermod seems to use the TX pin of the UART interface, one GPIO Pin and use python scripts.
petro function I can't explain :)
The Mausberry uses two GPIOs and a batch script.
Can someone tell me which one better, faster, more relieable?
What switches are needed for each? Momentary switches or just push buttons?

Or am I wrong?

moosepr

@obsidianspider couldn't you use a microswitch like the inside of an arcade joystick?

http://m.ebay.co.uk/itm/182057484715

Maybe if you can position it so the actual sliding switch hits the lever?