retropie – Jon Thysell

Building my own Sega Genesis Mini

September 1, 2022September 2, 2022HardwareLeave a Comment

It’s been several years since I posted Building a own custom retro console running RetroPie. That project was a lot of fun at the time, but I haven’t built another custom system since.

I just wanna play Sega Genesis

My original intent was to build something that focused on playing Sega Genesis games. The Genesis remains my favorite childhood console, and my dream was to build an emulation machine that looked like a Sega Genesis externally, but loaded with the entire library of games.

However the Raspberry Pi was still in its infancy back then, and I couldn’t bring myself to cannibalize an actual Genesis for its shell. Instead I settled on building my custom console with a generic case and (Xbox 360) controllers featuring a similar six-button layout. But that build just didn’t hold my interest for very long and I ended up digging out my original Sega Genesis, picking up one of Krikzz’s EverDrive flashcarts, and never looking back.

Fast forward to 2019, and Sega released the Sega Genesis Mini, which I happily picked up. It was my favorite of the official mini consoles, and it earned its spot on my desk at work. Despite the quick availability of hacks to add more games (and systems), I appreciated having such a tight, curated experience, even if I didn’t agree with every game choice.

Home office plans

Now it’s 2022 and that mini has mostly sat unused while I worked from home. As our offices have reopened, I’ve decided to split my time and to finally build myself a proper home office. And while I’ve kept a spot on my desk earmarked for a small “retro hardware setup”, I also have nice large TV and couch just begging for its own game system.

My first thought was to bring the Genesis Mini home, but it’s nice to have a self-contained setup at work for the days I go in. My second thought was to just pick up a Xbox Series S, giving me access to my modern digital library instead.

Then the Genesis Mini 2 was announced, so that became a contender. I looked at the game list, but unfortunately it doesn’t really excite me. However, in the process of watching various YouTubers’ opinions on the system, I stumbled upon some other projects that I’d completely missed before.

Blast 16 and the RetroFlag MEGAPi case

Blast 16 is a Raspberry Pi image designed to help you build your own Genesis mini console. Rather than just another RetroArch and Emulation Station setup, designed to host the full library of every retro console ever, Blast 16 is very Sega-oriented, and only supports the Genesis, Sega CD, 32X, Master System, and Game Gear. More than that, the beautiful, box-art-focused UI can’t handle more than a couple hundred entries without slowing down. So it’s meant to make you curate your experience, and only put on games you really want to play.

On top of that, and the real icing on the cake for me, is it’s easy to pair the Blast 16 software with the RetroFlag MEGAPi Case, which looks just like an actual Model 1 Sega Genesis. Seeing the two together in this video, my original dream was rekindled, and building my own Genesis Mini jumped to the top of my to-do list.

Getting the parts

My first concern was the age of these projects – they’d all come to market years ago, in response to the official Genesis Mini release. And if there’s one problem with these kinds of niche retro products, is that they’re often impossible to get if you didn’t buy them on day one.

Thankfully the Blast 16 website was still up and running, and I was happy to find that the MEGAPi case is still available on Amazon. I put in my order, and it’s quite lovely:

Next I gathered up two 8Bitdo M30 Bluetooth controllers (which I already had). The only thing missing was a Raspberry Pi.

I almost had a heart-attack seeing my (lack of) options. The MEGAPi case supports the Raspberry Pi 2B, 3B, or 3B+, but almost no one carries them anymore. I’d have to shell out $120 just for the low-end 2B, which is three times its original retail price of $40, and doesn’t even have Bluetooth.

Thankfully, past me had me covered. Checking my Amazon order history, I saw I’d picked up a 3B back in 2017 (who knows for what), and sure enough I there it was in my parts bin, still in the box. Bingo!

Building the hardware

Installing the Raspberry Pi into the MEGAPi case was simple and straight-forward – just plug in the two USB plugs, the single plug for the GPIO, and screw the board down:

Finally I flipped on the switch labeled “Smart Shutdown” (more on that later), closed the case and screwed it shut:

Initial software setup

With the hardware done, the next part was setting up a Micro SD card with Blast 16. I used a 16 GB card (no reason to waste anything bigger), and following the excellent instructions on the Blast 16 website, got the card imaged.

After that, I installed the card through the little lift door on the side of the MEGAPi:

After running the device once for the initial setup, and pairing the M30 controllers, it was time to install some games!

Installing games

Doing so was super easy. All you have to do is copy your ROMs (with matching box-art) onto a USB flash drive in a particular folder structure. Then if you boot the system with flash drive plugged in, Blast 16 will automatically install them onto the system. Note: if you want to remove games later, you can do so from within the Blast 16 menus.

I installed a little over a hundred games, mostly Genesis favorites, but also select few 32X, Sega CD, and Master System titles. It may not be the forever list, but it’s a great start.

Installing the safe shutdown scripts

One of the biggest gotchas with building a Pi-based anything is that the board doesn’t have a power switch. Out of the box, you’re expected to plug in the power to turn it on, and make sure to safely shutdown from within the running software to turn it off. If you don’t, and just pull the power, you risk corrupting the SD card and breaking your system.

Thankfully, the MEGAPi case wires its power switch and reset button to the Pi’s GIPO pins, and RetroFlag provides scripts you can install on your system to trigger a safe shutdown or restart when they’re used.

Update: Whoops! Apparently the base Blast 16 image already includes a working safe shutdown script that I completely missed. My version is unnecessary and installing it may give you some random error messages.

Unfortunately, RetroFlag hasn’t touched their code in a while, so the scripts have bugs and the install instructions didn’t work for me with Blast 16. I ended up forking their code and fixing the scripts myself for the Blast 16 / MEGAPi combo. I’ve written up revised instructions here, but long story short, if you want to copy my work, once you’ve gotten your Pi’s network configured, you just need to run the following from a terminal:

wget --no-check-certificate -O - "https://raw.githubusercontent.com/jonthysell/retroflag-picase-blast16/main/blast16_install.sh" | sudo bash

~~After it reboots the power switch and reset button will work as expected.~~

Final thoughts

I really love how well this project turned out. It looks so nice under my TV:

The UI is beautiful, and while I normally like the clean, pixel-perfect look when emulating, I’ve found I really like simulating an old CRT on this setup by setting the scaling to 4:3, turning on scan lines, and enabling the NTSC composite filter. Note: that last option meant going into RetroArch’s menus, so while that isn’t strictly necessary, I like that it’s still available.

In fact, having access to RetroArch’s menus meant I was also able to enable RetroAchievements, which was listed in Blast 16’s FAQ as unsupported. It works great, and I find adds a whole new level of fun when playing these old games.

Overall I’m thrilled to finally fulfill this old dream of mine, and while it doesn’t have literally every single game, I expect to spend plenty of hours playing my custom Sega Genesis Mini.

/jon

Building a custom retro console running RetroPie

March 15, 2015March 16, 2021Hardware2 Comments

Ever since I first heard about Raspberry Pi and the RetroPie project, I’ve wanted to build a retro console. Something with all my favorite old game systems emulated in a compact classy box, with nice controllers and fully customizable.

Back in the day I used to have a soft-modded Xbox original to play retro games, but it was loud, bulky, and the controllers weren’t great. When I got my first Raspberry Pi, I tried to make my custom console, but I ran into several problems:

Power issues: A non-clean shutdown meant corrupting the SD card, which isn’t user-friendly, and no power switch
Weak ports: Connecting straight to the light-weight Pi meant it was often left hovering in the air, which would strain the HDMI and USB connections
Available cases: Raspberry Pi cases all seem to fall into the category of tight as possible, giving no internal room to address 1 and 2 above

My first successful attempt was of course building the Picade, but it has two major limitations:

One player only
Kind of heavy to play on a couch

Since then I’ve been planning a new machine. The goal has been a small, two-player console that connects to modern TVs. Then after I discovered this lovely Polycase ZN-40 electronics enclosure, I new it was time to get to work. Yesterday was Pi Day, and I’d just cloned my Picade SD card, so I decided to finally try putting a console together.

It went together way faster than I anticipated! Now I can’t wait to make a couple more: one for home, one for work, one for the game room… the opportunities are endless.

Okay, enough typing, time to play!

/jon

P.S. Here’s a quick video and some development pics:

Building the Picade Mini Part V, final touches

April 5, 2014March 16, 2021Hardware9 Comments

In Part I I put together the cabinet, in Part II I got the main electronics installed, in Part III I created a custom rear jack panel, and in Part IV I got everything up and running 95% how I wanted.

After that last post, I took the machine to work to show off. Got lots of people to try it out, and the biggest bit of feedback was people wanted their MAME games. I also really wanted to play six-button Sega Genesis games. So I spent some time updating my secondary RetroPie build to the latest version, which gave me a much more functional Genesis emulator, including save state support and six-button controls. Then I switched to mame4all-pi, and put the correct MAME roms on the box, which finally gave me working MAME games.

Once I was sure the update would improve things without breaking my Picade, I went ahead and switched back to that build. I updated the Picade, and when that was done, it turns out I was using the wrong resolution before. The Picade Mini has a 4:3 screen, and I was outputting widescreen before. Once I fixed that, I changed the splashscreen to use the official Picade art from the Kickstarter.

The last bit of work was getting MAME working. It involved making all of the requisite folders mame4all-pi needs to save configs and high scores. Once that was done, I spent the time to go into MAME and reconfigure all of the controls to use what I have on my joystick. Everything I’ve done is in the updated configs file I’ve attached at the bottom of this post.

Here’s an updated video of the build in action:

And the original video if you missed it:

Enjoy!

/jon

My Picade Configs [184k ZIP] Updated 02-JUL-2014

I’ve configured my build to use as much screen real estate as possible without compromising on aspect ratios. The buttons are set up such 1-6 on the top map to playing buttons (Y X L B A R), the front are for Start and Select, and the side buttons are Escape and Control. Holding the right side button while I hit another button performs various emulator commands:

Left side – exit the emulator and return to the menu
B (bottom row, first button) – lower volume
A (bottom row, 2nd button) – raise volume
R (bottom row, last button) – hits Ctrl+C to forcefully exit any game
Y (top row, first button) – load state
X (top row, 2nd button) – save state
Select – bring up emulator menu

Includes configs for all of the RetroArch emulators, and for mame4all-pi. Feel free to change the configs to support your own needs.

Building the Picade Mini Part IV, let’s finish this up!

March 5, 2014March 16, 2021Hardware14 Comments

In Part I of this build, I put together the main parts of the cabinet. In Part II I got the main kit’s electronics installed and tested. In Part III I created a custom rear jack panel.

Next step was to finally install the rear door. The included hinges and latch worked perfectly.

With the rear door in place, it was time to install the Raspberry Pi and put into effect my grand wiring scheme.

The goal has always been a single power supply with a single power switch to get me into a ready to play system. With that in mind I installed a single throw, double pole switch.

The first pole is responsible for powering the monitor and customized USB hub directly. For the monitor I used the cut off the barrel-end of the included power supply. For the USB hub I severed the power leads for the host plug (so that it would never draw power from the Raspberry PI itself) and ran new power lines straight out the side. Simple enough, and both devices power up as soon as I hit the switch.

Now for the Raspberry Pi itself, I need something else. If I run power straight from the switch to the Pi, then killing the power threatens corrupting the Pi’s SD card and killing the machine.

Since it’s a common enough problem, and since I didn’t want to reinvent the wheel, I simply used a Mausberry shutdown circuit. In concert with a small script that runs on the Pi itself, what the shutdown circuit does is uses a pair of GPIO pins on the Pi to monitor when the Pi is running. When the switch is thrown, the circuit tells the script to tell the Pi to perform a clean shutdown. After the shutdown occurs (killing the script), the circuit finally cuts power to the Pi.

So essentially I wire power straight from my jack to the shutdown circuit, and attach the second pole of my switch to the designated spots on the shutdown circuit. (There’s also room for an emergency swtich to reset the Mausberry circuit itself, but I didn’t bother).

Sum total is that when the power switch is turned on, everything is powered on. When the switch is turned off, power is cut immediately to the monitor and USB hub, and a signal is sent to the Pi to shutdown cleanly. About 2-3 seconds later, the Pi shuts down and power is cut to the Pi.

So as long as I don’t physically pull out the jack, I can safely hit the power switch to power off the machine, even in the middle of a game, as long as I wait for a few seconds before pulling the actual plug. The speakers pop when the Pi loses power, so I know I’m safe to unplug.

The last bit of hardware setup was to connect the Pi in to everything. I connected the shutdown circuit and Ethernet jack to the Pi and both the rear USB jacks and the Picade controller to the USB hub (I’ll explain why later). I connected the HDMI from the monitor to the PI and the audio out from the Pi to the Picade board.

Finally, time to start playing with the software!

My first attempt at building an emulator rig with Raspberry Pi used the wonderful RetroPie Project. Since I had already gotten that up and running on another build, (with lots of games working) I decided to take a shortcut and clone that SD card as my starting point for my Picade.

First I tweaked the config.txt to optimize the display for the Mini’s screen (I’ll attach my config at the end of the post). Then I configured the Picade joystick as the new (and only) device. Again, I ended up needing to reprogram the Picade controller, as the default key selections, while great for MAME, actually caused all kinds of problems with RetroArch, which is the framework a lot of my emulators were using. (Again, I’ll add my configs to the end of the post).

The last real configuration (and it still needs some work) was for audio. By default, if you have HDMI connected, the Pi won’t output audio from the 3.5mm jack. I fixed that with the Raspberry Pi sound troubleshooting guide. (Hint, it’s amixer -c 0 cset numid=3 1).

The only audio hiccup I still have is that by default the sound is at max volume at boot. And it is LOUD. Even worse, it seems like potentially something is shorting on the Picade board- such that if the Picade board is wired directly to the Pi, and a loud sound plays, the controls straight up die. The solution I found for the controls was to connect the Picade controller board to the USB hub instead. As for the loud sound, my current workaround is to go in and out of the settings for Emulation Station (the front-end UI for the emulators) after boot. For some reason this resets the audio to regular ranges until I reset or power down.

After figuring that out, the box pretty much runs the way I want it to. I can play NES, SNES, GB, GBC, and GBA without any problems. Master System doesn’t work too well. Genesis works but the emulator (Picodrive) for some reason is locked to 3 button mode only. I haven’t gotten MAME to work yet- none of my roms are the right version it seems.

At this point the project is basically done. I might add a headphones jack, but the joystick itself is super loud anyway. The whole thing fits comfortably on my lap to play, but the front edge is sharp on the wrists so I might grind that down a bit.

Anyway, hope you enjoyed following my build!

/jon

My Picade Configs [184k ZIP] Updated 02-JUL-2014

Left side – exit the emulator and return to the menu
B (bottom row, first button) – lower volume
A (bottom row, 2nd button) – raise volume
R (bottom row, last button) – hits Ctrl+C to forcefully exit any game
Y (top row, first button) – load state
X (top row, 2nd button) – save state
Select – bring up emulator menu

Feel free to change the configs to support your own needs.

Update: See the video: Picade Mini build running RetroPie.

Update: Part V is up.

Building the Picade Mini Part III, with a custom rear jack panel!!!

February 10, 2014March 16, 2021Hardware3 Comments

Time for another Picade Mini update! In Part I of this build, I put together the main parts of the cabinet. In Part II I got the screen’s faulty driver board replaced and the screen and control electronics tested.

Now, according to the instructions, my last construction steps are to install the rear door and mount my computer. Then I should be good to start setting up the software. But, you don’t own something until you’ve modify it, so let’s modify this cabinet.

I wanted to have a cleaner rear interface than just a bunch of cables sticking out the pre-cut slots in the bottom of the rear door. My idea was to install some jacks, so my first step was to create a template of the jacks that I want- 2 USB, 1 power, 1 Ethernet, and a nice power switch.

At first I saw two choices: cut individual ports directly into the rear door, or cut one large hole and make a separate jack panel to mount there. Either way I’d need a template, so I did just that with a thin sheet of wood with graph paper glued to it. Then I traced out and labeled the jacks where I wanted them on the graph paper.

I used a drill press to cut the hole for the power jack and for the screws of the other jacks. Then I used a jigsaw and file to make the holes for the jacks themselves.

All in all, I was pretty happy with the template. It was a nice compact arrangement of everything I wanted. Next it was time to decide whether to start cutting holes in that rear door, or make a separate panel. Given the thickness of the rear door, I chose to make the separate panel.

The next question was what material to use? My first idea was to use a thin sheet of metal, or even to use another thin panel of wood. Instead my future father-in-law (whose workshop and tools I was using for this part of the project) suggested I try plastic, specifically a light switch blank. He thought it’d be easier for me to work with and look better than what I could make out of wood or metal.

Home Depot carried them in black for $0.89, so we picked up two and I got to work. He was right; the panel was really easy to work with. I transfered the template design onto it like a stencil with an awl and cut away. I’ll have to keep light switch blanks in mind when I’m working on electronic enclosures in the future.

After cutting out the holes and making sure everything fit, it was time to figure out where I wanted to mount it on the rear door. I chose the center bottom as the place to give me the most room inside the cabinet.

It was time to cut a hole in that beautiful rear door. I drilled holes to mount the panel and drilled out the corners so I could take the jigsaw to it. I cut out the smallest square I needed, and then for the moment of truth…

Viola! My custom jack panel installed perfectly, and looks way better than I expected! I realize it’s a little dirty in the pic- it got some glue stuck to the panel and I was too excited to take a photo to clean it off first. Now all I have left for the physical part of this build is to wire everything up and get that rear door installed onto the cabinet.

Stay tuned for the next part when I do just that!

/jon

Update (03/05/14): Part IV is up!

Update (03/05/14): See the video: Picade Mini build running RetroPie.