How to configure mono/traditional DMD (P-ROC)¶
|Related Config File Sections|
The P-ROC can drive a traditional single-color pinball DMD via the 14-pin DMD connector cable that’s been in most pinball machines for the past 25 years, like this:
1. Connect your hardware¶
2. Add a physical DMD device entry¶
Once you have your hardware and port set, you need to create the actual device entry for the DMD.
You do this in the
dmds: section of the machine config. This
section is like the other common sections (switches, coils, etc.) where you
enter the name(s) of your device(s), and then under each one, you enter its
(And yes, in case you’re wondering, it’s possible to have more than one physical DMD.)
To do this, create a section in your machine-wide config called
dmds:, and then pick a name for the DMD, like this:
dmds: my_dmd: shades: 16
You need to have at least one setting for this to be a valid YAML file, so we
usually just pick the
shades and add that with a value of
means the DMD runs will convert the display content to 16 mono shades when it
The “shades” option is how many brightness shades you want. 1990s WPC machines supported 4 shades, and modern Stern DMD machines support 16. The P-ROC supports 16 shades (even on older 1990s plasma DMDs). Most modern games will probably be 16 shades, but you can do 4 (or even 2) if you want an old school look.
There are lots more options for the physical_dmd: section than just the “shades” option listed here. Check the dmds: for a list of all the options.
Note that one option you do NOT have for physical DMDs is the color. That’s because the color of the DMD is determined by the DMD itself. You don’t actually send it color values, rather, you just send it brightness levels, and the DMD shows those brightness levels with whatever color the DMD is.
3. Set a source display¶
Now that you have everything configured, the last step is to make sure the DMD knows what content to show. In MPF, you do this by mapping a physical DMD to an MPF display.
By default, the DMD will look for a display (in your displays:
section called “dmd”. However you can override this and configure the DMD to
use whatever logical display you want by setting a
setting. (Just make sure that the width and height of your source display match
the physical pixel dimensions of the DMD or else it will be weird.)
4. Setting the DMD update rate¶
By default, MPF will send new DMD frames to the P-ROC at about 30 frames per second. (Technically it sends a new frame every 33ms.)
5. Fine tuning the DMD timing cycles¶
The P-ROC is able to drive a traditional DMD with 16 shades of intensity, ranging from off (0) to full on (15). Note that the P-ROC doesn’t control (or even know) what color the DMD is as that’s dictated by the DMD itself.
The P-ROC creates the appearance of 16 levels of brightness by rapidly turning individual dots on and off.
For years, DMD’s have been high-voltage gas plasma displays, though more recently they’re LED-based (even the single color ones with the 14-pin connectors).
Some people have reported less-than-optimal quality when using a P-ROC with certain types of DMDs. To address this, the P-ROC allows you to fine-tune the timings of the individual bit planes that make up the image.
For details on this, you can search the P-ROC forums
for “high_cycles” to find a few threads where people are talking about these
settings. Then you can set them in the
p_roc: dmd_timing_cycles: section of
your machine-wide config, like this:
p_roc: dmd_timing_cycles: 90, 190, 50, 377
Note that we do not have specific recommendations for values here and based on our experience, we haven’t found a need to change this. However, if you do have issues and you get new values by talking to the P-ROC folks, this is how you adjust them in MPF.
Our recommendation is that you leave the
dmd_timing_cycles: setting out
p_roc: config unless you need it and really know what you’re doing.
(There’s potential that bad values here could permanently damage your DMD
hardware, so again, only change these if you know what you’re doing.)
A final config you can test¶
At this point you’re all set, and whatever slides and widgets are shown on the DMD’s source display in MPF-MC should be shown on the physical DMD.
That said, all these options can be kind of confusing, so we created a quick
example config you can use to make sure you have yours set right. (You can
actually just save this config to
config.yaml in a blank machine folder
and run it to see it in action which will verify that you’ve got everything
To run this sample config, you can either run
When you run it, do not use the
-X options, because either of
those will tell MPF to not use physical hardware which means it won’t try to
connect to the Teensy.
Note that the Using a traditional (single color) physical DMD guide has more details on the window and slide settings used in this machine config.
hardware: platform: p_roc driverboards: pdb displays: window: # on screen window width: 600 height: 200 dmd: # source display for the DMD width: 128 height: 32 default: true window: width: 600 height: 200 title: Mission Pinball Framework dmds: my_dmd: brightness: 1.0 slides: window_slide_1: # slide we'll show in the on-screen window - type: display effects: - type: dmd pixel_color: ff5500 width: 512 height: 12 - type: text text: MISSION PINBALL FRAMEWORK anchor_y: top y: top-3 font_size: 30 - type: rectangle width: 514 height: 130 color: 444444 dmd_slide_1: # slide we'll show on the physical DMD - type: text text: IT WORKS! font_size: 30 slide_player: init_done: window_slide_1: target: window dmd_slide_1: target: dmd