Introduction: Minty Pi
A Minty Pi is a retro games console that fits inside of a Altoids tin.
It is powered by a 1200 mA battery and runs on a Raspberry Pi.
Credit to Wermy for the design.
Step 1: Supplies
For this Project you will need the following supplies:
MicroSD card - 8-16 GB
Access to a 3D printer for 3D printed parts
2.2" SPI TFT screen
Sound card (5V PCM2704 Sound Card Decoding Module DAC Decoder Board)
Adafruit Micro-Lipo Charger
1200mA 3.7V Lipo battery
DS-Lite Input Buttons
Step 2: Case
3d print the hole guide for the tin.
Using a sharpie, mark the borders of the holes.
Before you start drilling and filing, apply masking tape to the tin edges to make sure that no metal shavings get stuck and come loose later to short out a circuit.
It is best to start with the smallest drill bit, then work up bigger drill bits.
For the USB slots, I first drilled small hole, then filed to make the hole fit the guide.
Step 3: 3D-Printed Parts
For the 3D-printed parts, PLA is good for the face plates and the back, however the hinges should be printed with a stronger plastic such as ABS.
The settings I used to print the parts are shown.
The STL files for the 3D-printed parts are here.
Step 4: Modifying the Sound Card
The sound card that we need has a USB jack and a headphone jack, however, we do not need these.
To remove the USB jack, first clip off the legs on either side of the USB jack with a wire cutter, then use a soldering iron to heat the connectors and slide it off the card
To remove the headphone jack, simply clip off the connectors.
We also want to move the crystal oscillator to the side of the sound card in order to save space.
Step 5: Modifying the Micro-Lipo Charger
For the Micro-LiPo Charger, we will also make some modifications in order to save space.
First, we need to remove the JST Connector, which can be done by clipping off the supports.
Then, use a soldering iron to remove the two pins.
We will then bridge the 500 mA connector with some solder since our battery is 1.2 A and can handle the increased charge.
Step 6: Connecting the Micro-Lipo Charger to the Battery
Connect a red wire to the BAT pin and a black wire to the GND pin.
Then, connect the red BAT wire to the power switch.
Since we removed the JST Connector, we will solder the battery directly onto the charger.
Use a Micro-USB connector to align the charger with the micro-USB hole in the Altoids tin.
Use hot glue or tape to attach the charger to the base plate.
Use some scotch tape to affix the battery to the tin.
Hot glue the power switch in the rectangular hole.
Step 7: Connecting the Screen to the Raspberry Pi
If you are using the 2.2" SPI TFT Display Module like the one here, then we can connect the screen by soldering the wires from the display ports to the GPIO ports
We need to remove the soldered pins from the connectors. We will then solder wires from the display ports to the Raspberry Pi's GPIO ports with the following pairings:
SDO/MISO----------pin 21 (GPIO 9)
LED-----------------pin 12 (GPIO 18)
SCK-------------------pin 23 (GPIO 11)
SDI/MOSI-----------pin 19 (GPIO 10)
DC/RS---------------pin 18 (GPIO 24)
RESET---------------pin 22 (GPIO 25)
CS--------------------pin 24 (GPIO 8)
GND-----------------pin 20 (GND)
VIN-------------------pin 17 (3.3v)
Then solder the wires to the raspberry pi's GPIO ports, making sure the keep the wires in order.
Step 8: Burning the MintyPi Image
Step 9: Finishing
Place some electrical tape over the raspberry pi to to keep it from interfering with the battery.
Affix the Raspberry Pi to the face plate.
Start up the Raspberry Pi and run the programs to make sure that everything is working correctly.
Screw the face plates into position and you're done!