Introduction: Turn an ATGAMES Portable Sega Genesis Into a Wireless Set of Speakers.
If you've read my first instructable on how to modify a new better battery for the ATGAMES portable Sega Genesis then you might be wondering:
Q: What would I do with all that new found power?
A: Modify the ATGAMES Portable Sega Genesis into a wireless set of Bluetooth speakers.
Adding a Bluetooth receiver, amplifier and speakers to an ATGAMES Portable Sega Genesis wont make it the next Beats Pill but putting one together myself will be fun and much cheaper around 20 dollars. To be clear this mod does not add stereo sound to the console or its games, it will simply be a nice wireless set of speakers.
The Bluetooth chipset used is based on the Win-668 firmware. It announces a greeting when powered on and will take calls if it is paired with a cell. This means that it will verbally announce a call and pronounce the incoming phone number. It will basically behave like most Bluetooth car stereo connections.
The single built-in speaker was and still is partially to blame for the consoles bad sound reputation. The sound emulator itself can be worked around with Neto's Boot Loader but the built-in speaker still sucks. Also after reading about the excellent hardware hacks here at Sugar Electronix I learned that I cannot fix that speaker or use the built-in mono headphone jack as a stereo line-out without trying to include that guys work. It is an interesting read and well worth the time if you really want to know about more the console.
Parts purchased for the project.
Bluetooth 4.0 Audio Receiver - best-for-sell is #1 Thank you for the documentation!
Mu-metal Mag Shielding
Step 1: Opening Up and Making a Plan
Open up the console and get measurements of available space for my components. The chassis curves on average about 8mm in depth from center to edge with the PCB components taking up about 2mm space rising from the board for 10mm or 1cm total. Perfect, plenty of room.
There is a small trough like area that is open and large enough for a small serial cable/wire run that I need to connect the receiver and amplifier together.
At some point I made up a wiring scheme that kinda made sense and of coarse things change when dreams meet reality so this is just a rough idea of all the parts, wires and locations. This diagram includes wiring for a line-out using what I mistakenly thought was the consoles built-in stereo headphone jack but it is indeed not Stereo and that also sucks but finding that out this lead me to this site Sugar Electronix where I learned that the designers crippled the CPU's audio output for the sake of saving a few pennies per unit.
Step 2: Remove Two Plastic Pegs
Remove two plastic pegs from the bottom Left and upper right then sand the surface flat.
The purple sand paper shown was free at a local dollar store.
Step 3: Lining Things Up.
Lining things up.
On the Left is the Bluetooth Receiver and the Amplifier on the Right.
The speakers shown are 8 Ohm 2W 7mm / 28mm.
Mark the components location using pencil because when held up to the light its easy to see where the speakers line up on the other side of the plastic.
This layout helped me understand that both chips should be flipped horizontally because the receiving BT antenna on the left should be facing away from a speaker magnet.
The amplifier on the right should be upside down exposing the amplifier's activity light to the backside of the console where a small hole will allow it to be viewed.
Clipping these pins off will allow the BT chip to fit much better.
This is mostly about ease of wiring and making sure the BT antenna can get the best signal possible.
Step 4: Complete and Test the Circuit
Quality tools and patience are required here.
The red LED was dead and that was sad but the variable color LED from Adafruit works.
The kink in the wire gives me some slack to adjust the serial cable.
Step 5: Can the Speakers
Adding speakers to the chassis had some challenges.
Because the speakers sit above both the embedded CPU and the consoles TSOP, the speaker magnets should be suppressed using traditional anti-magnetic speaker alloy.
Mostly electrons like to be free and strong magnetic fields in close proximity encourage electromigration and I just cannot have that happening in my beloved portable video game console from ATGAMES. In this case a simple shield should be enough. A dime size piece is all and that can be cut from the alloy using some regular scissors.
Step 6: Test the Shields
Here I can see the magnetic fields using some magnetic paper. The white circle on the left is the unprotected magnet and the one on the right is a speaker with the metal alloy shield. Most cell phones have a magnetometer built-in, so measuring and then recording the difference with a tool would be the most accurate method of determining if this is a good shield however using this paper is the most fun and it is easy to see if there are any magnetic hot spots.
Step 7: Wrapping Up
The speakers are made of a conductive metal so I need to wrap them in a way that will prevent them damaging the console. Using some clear tape with little flaps I protect the speaker diaphragms from the black electrical tape that will be layered in as part of the process. Place the metal alloy on top of the clear tape and then layer in black tape on top of it. Make sure to cover any bit of exposed metal. There is 1mm or so for tape built into the design with the parts used. In the last picture I have the Speakers and the Bluetooth bug ready to go.
Step 8: The Power Switch
The power switch was the hardest part for me.
I found what I thought was a good place to mount the switch on the consoles PCB and scraped away some laminate or material from the PCB exposing enough space to weld. I used a piece of clear tape here to hold the switch in place so it can more easily be welded into place. These power switch welds need to be really good because I really don't want the power switch to break free someday.
Next carving out the plastic for the switch at the location that I chose was very difficult. In fact I almost went through the plastic chassis with my blade. A mistake here would have left a gaping hole that couldn't be repaired.
Step 9: The Power and Crossing the Line.
With the switch in place its time to wire the power. The Power and the Signal ground wires cross between both halves of the open console so I temporarily use a piece of clear tape to line up both sides and hold them in place. That made it easy to determine the lengths of wire needed and how they might twist or fold into place when closing the console. An LC circuit can be added here to further reduce noise but it is not needed for this project.
Step 10: Signal Calling Ground Control
The Bluetooth side of the bug still needs a signal ground because its getting power from a board that its not directly connected to. This is important because the chip combo I purchased from my good friends in China, are meant to be installed in cars and not toys so it does not include a solder point for this but this is easily worked around.
Scrape open a weld point down to the copper on the Bluetooth Receiver and Console motherboard. Then weld a wire between the two. Otherwise, as my brother reminded me, amplifiers don't so work good if the signal/receiver and or the antenna are not grounded. Power and Signal to ground. Thanks Bro!
Note: It is a little interesting to hear the CPU talk while the Amplifier is wildly picking up noise on the speakers however that's not at all helpful for this project so make sure this signal ground has strong weld.
Step 11: Drill the Speaker Holes
Take some time to draw a pattern on the back of the plastic chassis and then very carefully drill some speaker holes. I used clear tape that isn't shown to cover the surface before starting. This makes it easier to mark on with a pencil and then later prevent tool marks in the plastic. When done pulling up the clear tape takes most of the mess with it.
Step 12: In the End, Its All In!
Flow chart diagram and speaker holes.
After all is welded, taped and screwed back together give it a try.
If nothing came apart and or exploded then perfect!
I chose a Zelda inspired pattern for the speakers. Thanks Paris!
Overall I am pleased with the results.
I am told that the sound is very clear and can be heard between rooms easily.
The BT antenna performs admirably with a range of around 25-30ft depending on the app. and environment.
It is lacking in the heavy bass department but the installed speakers do not distort easily.
I wanted larger speakers and that still might be possible. I need some 30mm speaker covers made... but this would require cutting the Zelda shields out into a couple of large holes. It could also all fall apart and sometimes its best to know when to stop.
Step 13: Fails
This is what it looked like when I discovered mono-sound built into the motherboard and I had to change plans.
I also replaced the console speaker that everyone hates so much because it was damaged somehow when it was removed. It has been replaced with an old speaker from a dead laptop. For anyone interested the speaker is 10mm x 4mm with zero tolerance. The D-PAD sits right above the speaker and messing with that would make the game part of the console kinda worthless.