NES + Raspberry Pi for retro gaming and media center (Difficulty Moderate)

[abishur]

Project Scope: A fresh take on an old favorite: take a working NES and add an r-pi to it without destroying the NES in the process

Project Materials:
Soldering Iron
Soldering Wick
Dremel
Working NES
passive USB hub
Wireless keyboard
Short HDMI extension cable (I went with a panel mount option)
Ethernet jack (again I went with a panel mount option)
Playstation 2 to PC adapter
Wireless Playstaion 2 controller

Project Description:
Take a working NES (well, in my case I hope it will be working when I finish ) modify it to hold a raspberry pi inside of it, and use it to stream videos to your TV and play retro gaming systems.

For my setup, I decided that I wanted to use the Playstation 2 wireless controllers, they cost about 15 dollars at gamestop, they have a very good review for working on computers, they're comfortable, and they have the buttons I could want to play all my old school video games... except maybe the sega genesis.

Project Steps
1. Mod the NES

I started first by doing a little house keeping to the NES I disabled the lockout chip and bent the pins on the 72 pin connector upward a little to make a firm contact with the game cartridge (you can read more about this and see other fun mods by going here ).

I'm also planning on swapping out the red led to be blue when the r-pi is on while keeping it red when the nintendo is on. I'm hoping this will result in a purple-ish tint when both are on.

Then came the real modding. There was no spot where the r-pi would actually fit nicely, so I cut out some space on the bottom of the board as shown in this photo (for reference, the power and rest buttons are to the top left of the photo)



I chose this spot for a couple reasons, I didn't have to cut any pylons to get it to fit, and from the outside, you'd never known I had cut it! If you cut any of those other ridges, it makes a big old hole in the bottom of the NES box.

If you remove the expansion box cover on the bottom, you can see the hole from the bottom of the NES



And here it is with the cover back on (what hole?)



Incidentally, I also had to cut the expansion port cover shown here



Here's a picture of the inside with the cover in place. I admit that I didn't make it overly pretty, but this is a part no one sees, so I didn't want to waste a lot of time with it.



Finally, here's a picture of the bottom of the case with a credit card sized object placed in it for reference



Now in hindsight, I made a little snafu. The SD card can't be accessed from outside the case! Oh well, once it's up and running I shouldn't need to swap out the SD card. It's no more an inconvenience than opening up a pc to get the hard drive I suppose.

Step 2 - Powering it

Originally, I was going to power it off a single 9V 3A DC adapter for the Nintendo, I would tap the 9V rail and feed it into a voltage regulator circuit of my design, then after the appropriate voltage regulation, attach it to the two pins in the GPIO strip that have been stolen off the GPIO and attached to the 5V rail instead.

Well to my surprise I find the following little goody in the NES



That's a voltage regulator it accepts a 7-12 V input and outputs 5V DC! Well I'm putting more Amps down it than it can handle so I've decided to swap it out (you can see in the photo above that I've already desoldered it). I'm thinking I want something that will just smooth out the 5V rail and use a 5V PSU rather than a voltage regulator and step it down from a higher voltage. So I'm open to suggestions.

Then all I'd do is jumper what used to be the the input to the output pins of where the voltage regulator used to be and attach my micro usb cable to those + and ground pins at that point. Nintendo gets 5V like it uses and the r-pi get it's 5 volts as well.

Step 3 - More case modding

Once my extension cables get in I'm going to mount the ethernet port and the hdmi port. I'm not worried about anything else on the r-pi since this is just a retro gaming and media center computer.

Step 4 - Front end?

I haven't decided yet, but I think I'd like have the r-pi boot up into a system chooser, it would be a basic menu controlled either by one of the controllers, or by an IR controller (maybe a usb to ir deal, if someone know a more direct way that'd be pretty fun too ) The menu options would either let me choose an emulator to pull up or a media browser. I'm not overly worried about writing a program to choose which program to run, but I'm open to suggestions on the media browser.

I'd prefer something a little cooler than just a file browser that would open a media player. XBMC is a strong contender assuming they port it over of course but I'm not sure how it would run as an application on the r-pi as opposed to the "OS" so to speak.

[Jessie]

I like. It will be a cool stealthy PC.

[abishur]

Powering Part Two:

I talked to a couple of my Electrical Engineering friends and we looked over the official NES schematic (provided by Nintendo back in 1992, thank-you google!) Basically, it uses the higher voltage for the rf modulator, but not really for anything else. And since any 5V adapter will have a voltage regulator in already, I don't need to duplicate my efforts by adding any sort of line conditioner provided I'm using a 5V power supply... which I am! This one to be exact.



I stole it off a USB hub that I don't need/use. Someday, when I need it again, I'll buy a proper PSU for the nintendo, but today it will provide the 800 mA the Nintendo needs, the 800 mA the r-pi needs and still have almost an Amp left over for the USB peripherals.

I'm going to talk about why I can get away with using this PSU, so if you care about the electrical side of life read on, if not, then just skip ahead to the paragraph I've started off with bold text.

Okay, so for those who care, the Nintendo uses 9-13V AC which it then puts through some circuitry to correct the flow of the current and bring it to 9-13V DC. As such, this means you can A) use a DC PSU from the get go without damaging anything and B) Use a PSU without worrying about the polarity. It's designed for AC, and AC alternates the current, ergo the Nintendo doesn't care which way the current it going, it will correct it to the direction the Nintendo requires.

Okay, moving on. At this point in time I'm uncertain if I want to hook the power into the micro USB power adapter on the r-pi and take advantage of the voltage protection circuitry, or rather use the 5V rail pins and take advantage of the full amperage offered by the PSU. If I go this second route, I'm actually going to modify the PSU itself with a self resetting fuse to protect it from the two devices drawing more current than it can handle, and that should take care of that.

So here's an image of the jumper pins where the voltage regulator used to be. Without the regulator, this means I need to be careful to only use a 5V power supply (I think I'll label that) but that's fine. The red cable on the bottom is where I tapped the +5V rail to bring power to the r-pi.



So with it all wired up it was time to give it a test run. I plugged in the power and turned it on... no smoke or pop so it passed the first test. I popped in a cartridge I have (Excitebike) and turned it on again.





Success! Here's a picture of the NES itself with the game inserted



As you can see, because of the mod I did to the 72 pin connector and lockout chip, I actually don't need to push the games down anymore.

I figured I should test the voltage levels and hit some snags. First of all, it turns out that the spot I tapped into the 5V line (where the voltage regulator use to be) only has power running to it when the power button is pushed on the NES. Oh well, no surprise there. What was a surprise to me was that by the time it makes it to the voltage regulator location, it's only getting 3.89 Volts! Well, it's probably 27 years old, so I'll cut it some slack. Regardless, it means I need to find a better location to get my power from.

Some testing showed that right before the power switch I have a reading of 4.6V, but I'm still not too happy with that number, I want a strong 5V to power the pi off of. I removed the top of the RF modulator box and did some probing around. Obviously, the point at which the power enters the Nintendo is where the voltage is best, a strong 5.18V. Here's a pic of where I'm going to source my power lines.



Sorry for the general low quality pics, I just use my cellphone to take the pics, it takes forever to actually take the picture and I don't have the steadiest of hands so the pics are often a little grainy

[abishur]

More power and case modding

First up is power. I switch from tapping the 5V rail at the point where the voltage regulator used to be, and put it right where the power comes into the raspberry.

Here's a pic of the jumper I put in place to replace the voltage regulator



And a pic of the new wire placements



I know that it looks rather haphazard to have that much bare wire next to all the circuitry but rest assured, it's quiet safe. That wire is actually quiet stiff and has no wiggle in it. It's not going anywhere (and it's the ground wire that is completely bare, the +5v wire is the one that's still half insulated.

Here's a look at the wire coming out of the RF modulator box



It passed the no smoke test, so it was time to try hooking it in. I stole the wire for the setup off a duplicate charger for my bluetooth headset I had lying around. The charger doesn't provide enough amps to power an r-pi and since it's a duplicate it's just wasting space! So I figured the best thing to test power would be the headset it used to go to.



Ta-Da! A good 5V coming down that wire to power whatever device I want (and I want to power the r-pi ) and the NES itself is still completely off! The one "oops" moment I had was when I noticed how long the cord is! It can loop around my NES box 3 times and still make it to the r-pi. Oh, well. I don't want to resolder it, so I'll just neatly tuck it away in the box.

I printed off the 1:1 business card that a forum member was kind enough to make and tested out the placement of my setup. I quickly noticed that it turns out the rf modulator box comes out a lot farther than I thought, and would get in the way of the LEDs (no big loss there) and would probably ram into the audio out. Now I don't need either of these things, but I'd prefer to have this be a no-mod to the r-pi build. So after some testing placements, I decided to completely take out the area surrounding the expansion port.

Here's the final product.



I left the cover connector slots in place so I can keep the expansion bay cover attached (I don't want to effectively leave the r-pi sitting on the ground here). Here's a pic of the r-pi print out in place



One hold up I'm noticing is the fact that the connection clip is right around the area where my usb is. I'll have to wait for the actual board to do further testing, but if it's an issue, I'll just more the r-pi down a little like so.



Finally, here's a look at the case from the bottom after all my modding



One thing I'm hoping with this design is that I'll be able to remove the expansion bay cover for both easy access to the SD card, and easy access to the r-pi itself!

Is the r-pi here yet? I'm going crazy being patient for it

[liz]

That's *fabulous*. Super-impressed.

[celerity]

I'm loving this, do please keep updating the thread as you progress!

/\dam

[celerity]

By the way, you ideally want a couple of these for a truly authentic emulator experience: http://www.stelladaptor.com/
They are expensive, but well worth it IMHO. The cheaper solutions polled for input quite slowly, which ruined the feel of many games and actually breaks some, like Grand Monster Slam (I wonder how many people never play these games again due to this, thinking their happy memories were playing tricks on them) whereas the Stelladaptor has no discernible delay. See here for similar opinions.

I see you plan on using PS2 controllers, which is cool, but I'm sorry, for C64 or Amiga games, only something like this will do:

[mard0]

Wow i'm impressed!!!
Please please Santa if you're flowing this forum, I promise to be a good boy forever and wont ask for any presents for the next 5 years if could get this for Christmas.

[abishur]

You bet I'll keep updating! Once I get everything said and done, I'm going to redo the first post to be one giant step by step and delete the follow up posts I did for readability.

I like the classic controllers you linked, but yikes! That adapter is expensive! I'll just have to suffer through with my PS2 controller. My initial desire was to find a way to connect controllers via bluetooth, then turn an NES or SNES or Sega controller into a bluetooth controller... but then I saw that a bluetooth transmitter would cost me 50 bucks! And there was the little detail of not knowing how to work a bluetooth stack In the end I went with the cheapest option, which was the PS2 to PC adapter and a wireless controller. It was 5 bucks for the 2 port adapter, 15 bucks per controller and another 13 for an 8 pack of rechargeable batteries equals about 50 per 2 remotes I want to use. And since my wife isn't a big gamer, that's a total of 1 controllers I need right now

[singapura]

Great job! Since it's a NES I would go for these babiesThey have enough buttons for NES games but if you prefer you can use a SNES controller from the same site. A PS2 controller kind of ruins the retro feel i.m.h.o. If the price is an issue why not go for something like this.

[abishur]

One of the secondary things I was going for with my controllers is to have them be wireless. I can't stand a bunch of cables mucking things up during a gaming sessions, especially if you want t o play for just a little bit several days in a row. Any time you want to take a break you either have to step all over the cables or bundle them up in mess by the TV (It doesn't help anything that my TV is a good distance from the couch so I always have to buy extension cables as well)

[singapura]

Quote from abishur on November 29, 2011, 13:15
One of the secondary things I was going for with my controllers is to have them be wireless. I can't stand a bunch of cables mucking things up during a gaming sessions, especially if you want t o play for just a little bit several days in a row. Any time you want to take a break you either have to step all over the cables or bundle them up in mess by the TV (It doesn't help anything that my TV is a good distance from the couch so I always have to buy extension cables as well)

But, but, but that's part of the retro fun! I do understand where you're coming from though. How about using a bluetooth plugin and a WII controller? You could even plug in a Wii classic controller, which would make it (semi) wireless.

[abishur]

I might yet do something like that. Especially if I can use that to get the light gun working for nes/snes/sega games. But they're rather expensive, someone else would have to get it working first (I don't know how to do any bluetooth stack programming), and the controllers themselves are fairly prices (plus they have the added cost of purchasing a "classic" controller and I don't really like the feel of the classic controller). But hey, if someone wants to take my mod and mod it, that's pretty nifty too!

[celerity]

I'm tempted to use just the *idea* of your mod as an excuse to trawl eBay for a NES!

My long-suffering wife wouldn't be too impressed though, given the office and lounge already houses a Dreamcast (with arcade controllers for Soul Calibur ), N64, Xbox (1st gen), Megadrive and PS2 (with 4-player multi-tap ), and there's a Gamecube, C64 and Amiga in the loft (I still play games on those platforms, but the emulation is so perfect I don't get the hardware out very often).

/\dam (who is suddenly feeling the urge to play Supercars 2)

[tnelsond]

The original NES is just too bulky and the pins are always shot. What I'd prefer would be http://en.wikipedia.org/wiki/N.....l_NES-101) the top loading NES, though it might be harder to fit a R-Pi in there.

[abishur]

And look even less retro then my wireless controllers The pin issue is actually a really easy fix and uses just a safety pin. The basic issue is that since the device requires you to push the cartridge down it actually pushes the pins down as well on the 72-pin connector. Over time this created finicky pins that weren't really touching. You could either buy a new 72-pin connector, or use a bent safety pin to pull the pins back up. I did the latter and I actually don't have to push the cartridge down anymore to play it meaning I shouldn't have to worry about the pin issue ever again (though I might be forced to replaces some caps at some point) )

[abishur]

I'm hoping to have the next piece of my setup today (the HDMI panel mount) so I'll post some pics once I get things set up, but in the mean time, here's the next part of my idea.

On the flip cover lip I'm going to put one of the two following images





I tried to use the same font look as the official Nintendo logo that's already on the device. The first image has the second line spaced out to take about the same amount of space as the first line.

The second image has the same spacing for both lines (I might change it to have a little more space between Pi and Inside)

Edit: Like this



What do y'all think, which is your favorite?

[abishur]

Yay, my panel mount HDMI cable arrived today!

A quick stop with the old dremel and drill and here it is!



Here it is from the top with my print out of the r-pi



This was a fairly straight forward part of the mod, I made my measurements and stuck it in. As you can see, I went with the back right (when looking at it from behind) part of the case just to the right of one of the ridges. It was a bit tricky to get the inner dimensions to line up with the outer dimensions (in fact you can see that I actually put my first drill holes just slightly too far to the left). But all in all, a nice look.

I have noticed one little problem. The cable is really stiff, not a lot of flex to it. This might create a problem for me when I go to plug the hdmi in. My thought at this point is to buy two right angle adapters for the hdmi. The first will bring it out of the r-pi and go up, I'll have to make a cut out in the metal shield on the NES (no biggie), then I'll put a right angle on that bringing the it from an upward angle to a pointing to the back angle (so a 180 twist) this will also allow me to put all the excess cable in the metal shield part... or something like that. I'm rapid hitting the point where I need the r-pi itself to get everything nailed down... I think all i have left that I need to do is to mount the ethernet and *maybe* a usb as well

[Vindicator]

Work for the army and use these all the time for routing and stress relief of cables.
they have a self stick back and hole in the middle we normally drill a hole and then a self tapping screw to make sure they stay in place in desert heat.
then just a zip tie and all the stress is on the mount and zip tie not the component.
don't know if this might help, but I tried LOL.
note I work on reverse osmosis water purifier that uses an AB 5/03 slc500 components in 13 card backplane.

[abishur]

Oh, I guess I didn't state my problem too clearly now that I look at it again. Because it's so stiff, it looks like I might have an issue when I plug it in. The cable itself looks like it will stick out too far. I'll have to test things when I actually have an r-pi rather than make any more blind alterations though

[Vindicator]

I see what you might mean as the connector is on the opposite side of the case and by the time you plug it in you can not bend it enough to clear the side of enclosure in its present location.
so the 90 degree adapter makes sense now.

[celerity]

I prefer this label:


But... I personally would slightly reduce the spacing between "Pi" and "Inside" (just not as much as in your second image).

/\dam

[abishur]

@Vin - The humorous thing is that even a 90 degree adapter would be insufficient, the cable would take too much space point up to, I need to do a 180 or something!

[abishur]

Adding the ethernet

I added the ethernet to the NES. This one was a little bit easier to place. I put it to the right of the HDMI port as you'll can see.



This was a little easier to put in then the HDMI was. The metal part on the front comes off and I was able to use it as a guide for the screw holes and the big hole for the ethernet port. As you can see it's actually designed to be able to access a jack like a mic jack, but it will work just as well for a regular ethernet cable.

Here's a view from the top with a test cord plugged in.



Now as you can see, it was a bit of a tight fit with the cable in there, and the plug actually point down which makes it hard to remove. I may flip it upside down to fix that issue.

The HDMI cable is still looking like it's going to be an issue, I'll just have play around once I get the board... just a little bit longer, just a littler bit longer, breath in, breath out.

I'm also noticing that once I get things put in here things are getting a little more packed than I had expected. I'm already planning to not put the metal shield on that covers the bottom of the board, I might put some card stock there just to make sure there's a barrier between the NES board, we'll see.

I'm also thinking about removing the expansion port, but only if there's no space for the HDMI cable. The expansion port isn't used for any American games. But I'd prefer to get away without major revisions to the board.

I did decide to go ahead and add a usb mount to the outside (I don't think all my usb items will fit in there and it would be nice to be able to access the ps2 wireless cards as sometimes you need to hit the front of them to get them to sync up). So I've ordered those and I'll post when I get them.

One final thing, I showed the image I plan to put on the outside of the NES, but it's a fairly tight fit so I was thinking about making it much larger and putting it on the top of the NES. Thoughts?

[abishur]

No sooner did I finish posting then I went ahead and flipped the ethernet upside down!

Not only does it allow for easier remove of an ethernet cable, but it also moves the cable to the skinnier part of the pylon and it doesn't put so much stress on the mount. Here's a pic of it with the board put back in place. If you look just to the right of the red ethernet cable you can see the hdmi mount down there

Edit: If you look at the HDMI and mirror it such that you're now on the right half of the unit, that's where I'm planning to put the USB... when it get's here... hopefully on Tuesday or Wednesday. /Edit



Further Edit: I suppose I could have had all the cables come out the bottom by the expansion port and use one of the ridges on the bottom of the unit to neatly route the cables out under and way from the unit, and have saved myself around 30 bucks... but this just looks *so* much cooler. I just wanted to note that for anyone looking to do this project on a budget, I just happened to have some amazon gift cards and decided to spend them making it look that much cooler.