Remove Microcontroller
The Computer Perfection game ran on a 4-bit microcontroller, the Matsushita MN1400ML.
Carefully pry it up to remove it from the DIP socket. We won't be re-using the chip, but we will use the socket to connect all of the buttons and switches to our Metro M7. A rather large upgrade!
Wiring Diagram
The Fritzing diagram and schematic below show the connections we'll make to use the Computer Perfection game's buttons and switches as GPIO inputs on the Metro M7.
You can also see the connections to the I2S amplifier and NeoPixels.
DIP Header Wiring
Rather than tediously solder wires to the underside of the board, we'll use this super cool DIP header that Jan Goolsbey suggested.
These are designed to clamp down on flat ribbon wires, but in this case we'll use silicone sheathed wire for the necessary flexibility and low profile that'll allow the wire bundle to be routed out and under the board.
A pair of tweezers works well for pressing each wire into its pin slot -- no need to remove insulation, the pin does the work for you.
Using the Fritzing diagram as a guide, run each wire to its respective pad on the Proto-Screwshield.
Socket Connection
Paying attention to the orientation, place the DIN connector in the DIP socket, being careful to seat each leg so that nothing is misaligned or bent.
Use tape to neatly dress the wiring off to the left side of the board.
Wiring Length
Remount the PCB to the Computer Perfection top panel so you can pull the wires to even length in the Proto-Screwshield.
Remove a bit of the insulation and solder each wire.
I2S Amp
To prep the I2S amp, first solder the header strip and terminal block as shown here.
Solder a 7-pin section of socket header pins to the proto area of the Proto-Screwshield.
Run wires to pins D9, D10, D12, GND, and 3.3V as shown to correspond with the pins of the amplifier, connecting them to their respective pins on the headers.
Feed the speaker wires through the base and screw them into the terminal block.
Plug the amplifier into the board.
NeoPixel Wiring
We can't re-use the existing LEDs on the board easily because they are wired to the same pins as the input buttons -- the original microcontroller pins toggled quickly between input and output to perform both functions -- so we'll upgrade the Computer Perfection with a strip of NeoPixels!
Solder terminal blocks to the Proto-Screwshield to accommodate the NeoPixel wiring to pin D11, GND, and 3.3V.
LED Placement
Remove the PCB and test fit the NeoPixel strip, then cut off the excess as shown.
Use the uGlu dashes or other adhesive to affix the NeoPixels, running the wiring to the side as shown.
Put the PCB back onto the top panel.
Screw the NeoPixel wires into their blocks and then you can plug the Proto Screwshield into the Metro M7.
USB Cable
Assemble the DIY USB cable USB-C end to the ribbon cable and plug it into the Metro M7.
Run the ribbon through the base as shown, then attach the micro-B socket.
Metro Placement
Use double-stick foam tape to adhere the Metro M7 to the inner base, then screw the top panel into place.
Page last edited March 08, 2024
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