1. The RGB LED Panels
The panels we use are sold for video walls and advertising signs. There are many sizes of panels available with different spacing between the LEDs. The ones that fit best into a pinball have 2.5mm spacing (also referred to as P2.5), which results in a 128×32 display of 320×76.8mm. This can be mounted into an existing DMD/speaker panel from a pinball cabinet. Currently the only place to buy these panels is from AliExpress. Search for “RGB LED 64×64 p2.5 1/16” or “RGB LED 64×64 p2.5 1/16”. You don´t find 128×32 panels, but you can buy two 64×32 or one 64×64 panel which consists of two 64×32 panels which can be removed from the frame and connect side-by-side. Make sure that you end up with panels which have 1/16 scan and this HUB75 pinout since this is the only type currently supported by PIN2DMD. The good thing is that they are seamless.
2.1 The STM32F4 Discovery board with PIN2DMD Shield
The panels use a 16 pin Hub75 interface to be connected to the next panel or to a controller. We use a STM32F407 discovery board which is available from multiple sources for about $20. It is based on 168Mhz Cortex M4 processor architecture which is needed for the rapid bit-shifting of data to control the panels. We use CooCox IDE to write the program in C. The software is uploaded to the controller through mini USB port.
To connect the displays to the controller you need a connector shield pcb, which basically just connects the pins to the 16-pin ribbon cable that drives the displays. The board also has a 14pin connector which can be either used as output to a real monochrome pinball dmd or as input to get the data from a real machine. A PCB layout example can be found in the pcb directory. The advantage of the modular system is that new hardware functions can easily be implemented by changing the shield while keeping the controller. Members of the community have organized a group buy for printed circuit boards and also offer different kits. Search for PIN2DMD on german flippermarkt forum or VPUniverse forum .
3. The Power Supply
The RGB LED displays require 5vdc for power and if you want to run them with full brightness they need a lot of current. A 5A power should be enough. You need to connect that power supply up to both panels. The controller can either be supplied by USB or by an external 5V power source
4. The Frame
For perfect alignment of the panels side by side a laser cut frame is recommended.