RGB LED panels for DMD replacement

0

22

#1 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

In January I noticed that you could get RGB (full color) LED panels for building outdoor display screens that were almost small enough for pinball DMD replacements and started a thread over on the Pinball Controllers forum as a potential DMD like screen for home-brew projects.

KrustyDMD.jpg

Last month I saw that you can finally get them directly from China in 2.5mm spacing which is practically identical to a regular DMD so I started working on getting a board going for them. Today a new user, lucky1 arrived here looking for colorized ROMs for testing his very similar project, so I decided it was time to let the cat out of the bag and start getting some information out there even though I won't have an actual 2.5mm screen to show until this weekend.

My project is using a Teensy 3.2 (Arduino like, but much more powerful) microcontroller on a custom carrier board, and lucky1 is using a Discovery STM32F4 Board (similar processor, but a little faster and larger). Not sure what the final results of these two efforts will be at this point, but either way this is going to be an option soon, both for homebrew and DMD replacement, and they should be very cost effective either as a DIY or simple kit.

0

#2 8 years ago

CCM

KingPinGames

Kingpin Games

Wisconsin Dells, WI

12y 112K 4,155 15

Looks great. What's the cost?

0

#3 8 years ago

JIM

winteriscoming

Pinside member

10y 85,300 2,654

Very cool!

What are you imagining the options for DMD replacement would be? Full colorization? Choose 1 color and just get different shades? Or maybe something like DMD Extender where each shade can be assigned a color?

Certainly something that's the same size as a standard DMD would be easier to install in a large variety of games. Installing an LCD in JP required some modifications to the speaker panel.

0

4

#4 8 years ago

DAD

MrBellMan

Pinside member

Concord, CA

11y 87,150 1,894 4 11

Just the fact that there may be a cheap alternative to replacing the DMD displays is good news!

0

#5 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from KingPinGames:
Looks great. What's the cost?

No idea if it will end up as a "product", but I'd say <$200. The parts will probably set you back something like $110 if you're willing to source from China and DIY on all the soldering and cables.

Quoted from winteriscoming:
What are you imagining the options for DMD replacement would be? Full colorization? Choose 1 color and just get different shades? Or maybe something like DMD Extender where each shade can be assigned a color?

WPC is probably best limited to shades of 1 color, although in theory I guess you could use a palette. On Stern it should be easy to use side channel or embedded SmartDMD data for full colorization for those with a PinballBrowser or SmartDMD license (I'm not sure exactly how Oga deals with those.) For homebrew you can send full color data from a host computer over USB.

0

#6 8 years ago

???

marcocapetown

Pinside member

Cape Town

11y 24,950 107 7

great for coming up with this... if u can do full color on wpc u sir would win over the whole of pinside.

0

#7 8 years ago

JIM

winteriscoming

Pinside member

10y 85,300 2,654

OP
Quoted from ecurtz:
WPC is probably best limited to shades of 1 color, although in theory I guess you could use a palette.

Palette choices even for 4 shades is preferable to being locked into one color. That's the big draw-back in my opinion to ColorDMD Sigma vs. SmartDMD/DMD Extender (well and price difference ).

I have pics of JP with DMD Extender here:
https://pinside.com/pinball/forum/topic/de-jurassic-park-with-lcd-dmd-replacement#post-1102230

Even being limited to 4 custom colors can lead to awesome results.

0

#8 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from marcocapetown:
great for coming up with this... if u can do full color on wpc u sir would win over the whole of pinside.

There's really not enough data in WPC to do full colorization. The ColorDMD guys get around that by looking up the frame and merging it with appropriate full frame color data they've stored separately, but they've patented that and this hardware probably wouldn't be up to that task anyway. If ColorDMD wanted to offer the LED panels as an alternative to the LCD screen they probably could, but I don't see any easy way to do full color on WPC without additional hardware.

0

#9 8 years ago

ABC

Crash

Pinside member

12y 141K 14,138

Quoted from winteriscoming:
Palette choices even for 4 shades is preferable to being locked into one color. That's the big draw-back in my opinion to ColorDMD Sigma vs. SmartDMD/DMD Extender (well and price difference ).
I have pics of JP with DMD Extender here:
https://pinside.com/pinball/forum/topic/de-jurassic-park-with-lcd-dmd-replacement#post-1102230
Even being limited to 4 custom colors can lead to awesome results.

Absolutely. Some more great results using this simple feature can be seen here:

https://pinside.com/pinball/forum/topic/diy-addams-family-poor-mans-color-dmd/page/4#post-1509520

How are you driving (clocking) the panel matrix in your Twlight Zone video? Are you using the original pixel refresh signals that would normally go to a plasma display? Reason I am interested is things like the lack of screen tearing and jitter as well as the pixel modulation for the different shades looks absolutely bang-on in your video. DMD Extender has some minor issues with not updating the color palette data between frames (planes) but granted you aren't using color in this example.

0

#10 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from winteriscoming:
Palette choices even for 4 shades is preferable to being locked into one color. That's the big draw-back in my opinion to ColorDMD Sigma vs. SmartDMD/DMD Extender (well and price difference ).
I have pics of JP with DMD Extender here:
https://pinside.com/pinball/forum/topic/de-jurassic-park-with-lcd-dmd-replacement#post-1102230
Even being limited to 4 custom colors can lead to awesome results.

The palette thing is easy, it's currently using a palette that's just 4 shades of gray. However I'm a little bit worried you'd get some color bleed on the current system, which is just summing the previous 3 frames to get each dot value. It would only last 120th of a second each time though, so maybe it wouldn't be an issue in practice, I'll give it a try.

EDIT: These caveats are all WPC of course, Stern varies the frame time so it's possible to determine which parts correspond to each intensity, but WPC is just a stream of identical on/off bitmaps all with the same timing.

0

#11 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from Crash:
Absolutely. Some more great results using this simple feature can be seen here:
https://pinside.com/pinball/forum/topic/diy-addams-family-poor-mans-color-dmd/page/4#post-1509520
How are you driving (clocking) the panel matrix in your Twlight Zone video? Are you using the original pixel refresh signals that would normally go to a plasma display? Reason I am interested is things like the leak of screen tearing and jitter as well as the pixel modulation for the different shades looks absolutely bang-on in your video. DMD Extender has some minor issues with not updating the color palette data between frames (planes) but granted you aren't using color in this example.

It actually isn't quite synchronized between input and output at this point (I think the WPC signal is 122Hz and the screen update is 124Hz) but you really can't tell. I have a scheme about how to fix that, but if it continues to be invisible it may be pretty far down the list.

0

#12 8 years ago

ABC

Crash

Pinside member

12y 141K 14,138

It's definitely nice to have a display that can be externally driven rather than having to stick with the fixed 60Hz refresh rate of an LCD-based solution. This is good as it represents the full motion fidelity of original plasmas (scrolling and other animations look butter smooth on the original panels) and allows you to (at this point in time, mostly) avoid tearing, skipped frames, and pulldown issues. Do you know if the plasmas are externally clocked? I have heard that different manufacturers use dissimilar refresh rates.

0

#13 8 years ago

ABC

Crash

Pinside member

12y 141K 14,138

I wonder, if this ever gets off the ground, if 6 of these displays can be used for a 192x64 Sega DMD replacement? Do you know how many of these can be connected together?

0

#14 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from Crash:
It's definitely nice to have a display that can be externally driven rather than having to stick with the fixed 60Hz refresh rate of an LCD-based solution. This is good as it represents the full motion fidelity of original plasmas (scrolling and other animation look butter smooth on the original panels) and allows you to (at this point in time, mostly) avoid tearing, skipped frames, and pulldown issues. Do you know if the plasmas are externally clocked? I have heard that different manufacturers use dissimilar refresh rates.

The plasmas are clocked externally as part of the signal from the CPU. As I said it looks like the TZ is running at 122Hz (according to my crappy Chinese knockoff logic analyzer). There may be some hardware differences from the manufactures that vary the actual display times or something, but I think they're pretty simple hardware wise, so these are probably minor.

0

#15 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from Crash:
I wonder, if this ever gets off the ground, if 6 of these displays can be used for a 192x64 Sega DMD replacement? Do you know how many of these can be connected together?

My poor little Teensy is about at its limit with 2, so you'd need some beefier hardware driving them. Also they eat a lot of 5v so you'd want a serious power supply. You could maybe manage on/off for a single color depending on what the original refresh rate was like. Are they divided up somehow or is it all one monolithic signal?

0

5

#16 8 years ago

JIM

winteriscoming

Pinside member

10y 85,300 2,654

Here's my advice if you plan to produce something that you'll be selling: Don't start an interest list!

People will beg you to do it and they'll even claim to be willing to throw money at you, but if there's too much time between announcing the product and releasing it, many people will drop out. I know from experience with a mod I'm selling... They want what you're showing RIGHT NOW, and they'd pay for it if it was available, but ask them to delay gratification, and they'll drop out.

0

2

#17 8 years ago

ABC

Crash

Pinside member

image.jpg

#18 8 years ago

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

But that worked so well on the TRON ramps.

0

#19 8 years ago

PGR

PhilGreg

Ayscrim Studios

Québec, QC

11y 99,800 2,446 6

OP
Quoted from ecurtz:
My poor little Teensy is about at its limit with 2, so you'd need some beefier hardware driving them. Also they eat a lot of 5v so you'd want a serious power supply. You could maybe manage on/off for a single color depending on what the original refresh rate was like. Are they divided up somehow or is it all one monolithic signal?

Dang.

0

#20 8 years ago

BIN

Hawkulous

Inactive member

Unknown

9y 20,150 30 1 8

Nice find! Please post a link for the source of the panels? They should work on my Rpi B+ project by changing a file or two! Might even be able to do without a loss of frames! The Arduino due also worked for me in capturing and processing Williams DMD signal. Good luck with your project!

0

#21 8 years ago

MDK

Crans

Pinside member

8y 43,150 160

Count me In for testing I'll have some pins around I'd love to give this treatment

0

1

#23 8 years ago

JOE

lucky1

Pinside member

Karlsruhe

8y 61,050 1,091 16

Let´s throw the code together. ecrutz has the real pinball dmd interface running , i have
the pinmame usb interface running.

Currently have a 12bit palette (4096colors) to chose the 16colors from I use to map
to the 16 shades of a Stern ROM or the 4 colors for the 4 shades of a WPC ROM.
I have a code sample here with 33bit palette which may be adapted to my code
but I think 4096 is enough by now. Sometimes it is already hard to seperate the 16 shades
of one color.

A video of my first colormapping implementation and more info can be found in the vpuniverse forum
(I´m not allowed to post links here due to the fact that I´m new to the forum)

I´m plannig to design a pcb with a connector for a classic DMDs like Stern, Vishay etc. driven by USB and Pinmame (like PINDMD2),
a connector for the china 2.5pitch RGB panels driven by USB and a classic pinball interface to drive the china panel. All with
color mapping to either a fixed palette or dynamic palettes with in-frame coding like SmartDMD.

I will use two RGX panels side by side
Search for "RGX-p3mm-Indoor-SMD2121-rgb-led-display-module-192mm-x-96mm-64-32-pixle-HD-Video" with the brackets on google.
They cost 21.50$ each plus shipping.

Regards

Lucky1

0

1

#24 8 years ago

JOE

lucky1

Pinside member

Karlsruhe

8y 61,050 1,091 16

OP
Quoted from ecurtz:
My poor little Teensy is about at its limit with 2, so you'd need some beefier hardware driving them. Also they eat a lot of 5v so you'd want a serious power supply. You could maybe manage on/off for a single color depending on what the original refresh rate was like. Are they divided up somehow or is it all one monolithic signal?

The STM32F407 I use should have enough power to handle this.
Search for HUB75 STM32F4 in google for a 33bit example with 9 panels

0

#25 8 years ago

PGR

PhilGreg

Ayscrim Studios

Québec, QC

11y 99,800 2,446 6

Quoted from lucky1:
The STM32F407 I use should have enough power to handle this.
Search for HUB75 STM32F4 in google for a 33bit example with 9 panels

Yay!

0

#26 8 years ago

ABC

Crash

Pinside member

12y 141K 14,138

Quoted from Hawkulous:
They should work on my Rpi B+ project by changing a file or two! Might even be able to do without a loss of frames! The Arduino due also worked for me in capturing and processing Williams DMD signal. Good luck with your project!

By "do without loss of frames" do you mean use the actual refresh rate from the WPC controller/driver for the panel?

Quoted from lucky1:
Let´s throw the code together. ecrutz has the real pinball dmd interface running , i have
the pinmame usb interface running.
Currently have a 12bit palette (4096colors) to chose the 16colors from I use to map
to the 16 shades of a Stern ROM or the 4 colors for the 4 shades of a WPC ROM.
I have a code sample here with 33bit palette which may be adapted to my code
but I think 4096 is enough by now. Sometimes it is already hard to seperate the 16 shades
of one color.
A video of my first colormapping implementation and more info can be found in the vpuniverse forum
(I´m not allowed to post links here due to the fact that I´m new to the forum)
I´m plannig to design a pcb with a connector for a classic DMDs like Stern, Vishay etc. driven by USB and Pinmame (like PINDMD2),
a connector for the china 2.5pitch RGB panels driven by USB and a classic pinball interface to drive the china panel. All with
color mapping to either a fixed palette or dynamic palettes with in-frame coding like SmartDMD.
I will use two RGX panels side by side
Search for "RGX-p3mm-Indoor-SMD2121-rgb-led-display-module-192mm-x-96mm-64-32-pixle-HD-Video" with the brackets on google.
They cost 21.50$ each plus shipping.
Regards
Lucky1

http://vpuniverse.com/forums/topic/2219-pin2dmd-color-pindmd-compatible-interface-with-led-rgb-color-dmd/

http://www.aliexpress.com/store/product/RGX-p3mm-Indoor-SMD2121-rgb-led-display-module-192mm-x-96mm-64-32-pixle-HD-Video/1359923_2028248192.html?aff_platform=aaf&sk=bm2aeAra%3A&cpt=1444219709028&af=6146988&cn=002&cv=11032041&dp=ifgr4ivl1p002eus008sc&PID=6146988&URL=http%3A%2F%2Fwww.aliexpress.com%2Fstore%2Fproduct%2FRGX-p3mm-Indoor-SMD2121-rgb-led-display-module-192mm-x-96mm-64-32-pixle-HD-Video%2F1359923_2028248192.html&aff_trace_key=62440d68f4f44be6ab24c71cdd4a48d2-1444219709028-09788-bm2aeAra

Quoted from lucky1:
The STM32F407 I use should have enough power to handle this.
Search for HUB75 STM32F4 in google for a 33bit example with 9 panels

http://www.element14.com/community/docs/DOC-48699/l/discovery-kit-for-stm32-f4-series-with-stm32f407vg-mcu?forceNoRedirect=true

http://www.st.com/web/en/catalog/mmc/SC1169/SS1577/LN11

https://hackaday.com/2015/01/05/rgb-led-matrices-with-the-stm32-and-dma/

0

#27 8 years ago

???

GetTheJackpot

Pinside member

10y 34,900 191

I was under the impression that Marco or somebody else had come up with replacement LED screens for games that accurately matched the size and pitch of the plasma displays. Pretty sure they were being tested in the Circus Maximus prototypes of Pinball circus.

Good luck with the RGB panels, most I'v seen require the use of an fpga to drive them, such as the following one from adafruit: http://www.adafruit.com/products/420

0

#28 8 years ago

ABC

Crash

Pinside member

12y 141K 14,138

Yes, Homepin. Was about to buy some then this happened:

https://pinside.com/pinball/forum/topic/new-pinball-announced-by-homepin-thunderbirds/page/3#post-963703

0

1

#29 8 years ago

BIN

Hawkulous

Inactive member

Unknown

9y 20,150 30 1 8

Quoted from Crash:
By "do without loss of frames" do you mean use the actual refresh rate from the WPC controller/driver for the panel?

Basicly yes ... -2 fps, maybe,
A little while ago I posted my Rpi b+ dmd project on the tech forum.
https://pinside.com/pinball/forum/topic/williamsbally-dmd-to-hdmi-raspberry-pi-b-project-with-source-code#post-2563487
but in this project there was some loss off frames,for various reasons. But I think with a couple of small tweaks, this project should be able to display the dmd images at 120fps on 2 of these LED panels, because you can use dma to dump the data to these displays while getting the next set of data from the DMD controller in theory.

0

#30 8 years ago

PGR

PhilGreg

Ayscrim Studios

Québec, QC

11y 99,800 2,446 6

Quoted from Crash:
Yes, Homepin. Was about to buy some then this happened:
https://pinside.com/pinball/forum/topic/new-pinball-announced-by-homepin-thunderbirds/page/3#post-963703

I remember reading this, but that was years ago... any news on that front?

0

#31 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from Hawkulous:
Nice find! Please post a link for the source of the panels? They should work on my Rpi B+ project by changing a file or two! Might even be able to do without a loss of frames! The Arduino due also worked for me in capturing and processing Williams DMD signal. Good luck with your project!

Does the Pi have enough GPIO pins to handle the input and output? The RGB panels require 13 in additional to the DMD input.

As far as I know the only current source for the panels in direct from China via AliExpress or similar.

0

#32 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from lucky1:
Let´s throw the code together. ecrutz has the real pinball dmd interface running , i have
the pinmame usb interface running.
Currently have a 12bit palette (4096colors) to chose the 16colors from I use to map
to the 16 shades of a Stern ROM or the 4 colors for the 4 shades of a WPC ROM.
I have a code sample here with 33bit palette which may be adapted to my code
but I think 4096 is enough by now. Sometimes it is already hard to seperate the 16 shades
of one color.
A video of my first colormapping implementation and more info can be found in the vpuniverse forum
(I´m not allowed to post links here due to the fact that I´m new to the forum)
I´m plannig to design a pcb with a connector for a classic DMDs like Stern, Vishay etc. driven by USB and Pinmame (like PINDMD2),
a connector for the china 2.5pitch RGB panels driven by USB and a classic pinball interface to drive the china panel. All with
color mapping to either a fixed palette or dynamic palettes with in-frame coding like SmartDMD.
I will use two RGX panels side by side
Search for "RGX-p3mm-Indoor-SMD2121-rgb-led-display-module-192mm-x-96mm-64-32-pixle-HD-Video" with the brackets on google.
They cost 21.50$ each plus shipping.
Regards
Lucky1

The output code in my version is branched from SmartMatrix, which uses extremely clever and efficient DMA for the pixel output. It's doing 12bit with the WPC example because that's all it needed and WPC is 120Hz, but it has support for 24 and 36 bit pixels as well.

It already supports streaming over USB for homebrew applications at 24bit color and 30fps, but it would be easy to modify PinMAME to provide screens if you wanted it for that.

DON'T use lucky1's search above if you want panels that will fit for a direct DMD replacement, you need the (brand new AFAIK) 2.5mm panels NOT the 3mm panels. "P2.5" often shows up in the description and the boards should be 32x64 pixels and 80x160mm. But unless you know C and like reading microcontroller datasheets it might be a little early to be buying panels anyway.

0

#33 8 years ago

T

Blackjacker

Pinside member

Long Hill, NJ

12y 83,800 2,474

Quoted from GetTheJackpot:
I was under the impression that Marco or somebody else had come up with replacement LED screens for games that accurately matched the size and pitch of the plasma displays. Pretty sure they were being tested in the Circus Maximus prototypes of Pinball Circus.

Hopefully this is still happening - haven't seen an update on that since May: https://pinside.com/pinball/forum/topic/pinball-circus-to-be-remade/page/11#post-2427492

Vishay currently sells a full-field 128x32 LED display, but it retails for bonkers money.

On Homepin's LED DMD:

The LED DMD project has been rolled into the Homepin pinball factory project and wil become part of our R&D in the new factory.

When production starts on them I expect they will be available ahead of any new pinball machines we are making.

Above from http://www.aussiearcade.com.au/showthread.php/56674-STOP-PRESS-New-Homepin-LED-DMD-in-early-development?p=795799#post795799

0

#34 8 years ago

ABC

Crash

Pinside member

12y 141K 14,138

Homepin's public image aside, his original plan was to manufacture a single 128x32 panel. However, his panels are monochrome only (white) and will be sold with color filters. He said something like 1 in 20 blocks had to be rejected due to manufacturing imperfections resulting in dead pixels (I think). But then again he mentioned something about replaceable pixels too.

0

1

#35 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Also, the bug Crash pointed out in the SmartDMD thread is going to be a big, annoying pain in the ass to fix, so everyone be sure to thank him for noticing it.

0

#36 8 years ago

ABC

Crash

Pinside member

12y 141K 14,138

The one about the pixels being cut off?

0

#37 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from Crash:
The one about the pixels being cut offf?

Yeah, but it actually looks like it might not be a problem and we can use a pin I thought was off limits. Sometimes it's better to be lucky than good.

0

#38 8 years ago

JOE

lucky1

Pinside member

Karlsruhe

8y 61,050 1,091 16

OP
Quoted from ecurtz:
DON'T use lucky1's search above if you want panels that will fit for a direct DMD replacement, you need the (brand new AFAIK) 2.5mm panels NOT the 3mm panels. "P2.5" often shows up in the description and the boards should be 32x64 pixels and 80x160mm. But unless you know C and like reading microcontroller datasheets it might be a little early to be buying panels anyway.

Even if the words in the search string tell something else, it leads to the RGX board with 2.5mm pitch. Click on the link to the RGX panels Crash posted. If you want to use it single color with PinMAME my code is already working just fine. Color Code for PinMame is on its way.
So why not be one of the first who tests it as a pindmd / pinball DMD alternative.

0

#39 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from lucky1:
The STM32F407 I use should have enough power to handle this.
Search for HUB75 STM32F4 in google for a 33bit example with 9 panels

Looking at his project those are smaller panels, so I think even with the extra CPU you're going to have a hard time pushing enough data for one of the big Sega displays. I haven't looked at the datasheet for one of them though, so there may be some tricks to help.

0

#40 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from lucky1:
Even if the words in the search string tell something else, it leads to the RGX board with 2.5mm pitch. Click on the link to the RGX panels Crash posted. If you want to use it single color with PinMAME my code is already working just fine. Color Code for PinMame is on its way.
So why not be one of the first who tests it as a pindmd / pinball DMD alternative.

Oops, I was confused by the description which seems to be talking about two different displays (it has conflicting info in the title and description). Did you order from those guys and get the 2.5mm panels? I'd be nervous about the weird description.

0

#41 8 years ago

ABC

Crash

Pinside member

12y 141K 14,138

What is the refresh rate for the Sega displays?

OP
Quoted from ecurtz:
Yeah, but it actually looks like it might not be a problem and we can use a pin I thought was off limits. Sometimes it's better to be lucky than good.

Not sure I understand, is a line just being skipped or repeated? The resolution of the panels is exact unless I'm missing something.

0

#42 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from Crash:
What is the refresh rate for the Sega displays?

Not sure I understand, is a line just being skipped or repeated? The resolution of the panels is exact unless I'm missing something.

It was a timing issue between the WPC DMD signal and the serial interface on the microcontroller that's reading it. The microcontroller has some requirements for what counts as a valid input that the display panel doesn't. Basically I need to take one of the DMD inputs and delay it so the microcontroller accepts the last bit of the message / last dot of the display.

0

#43 8 years ago

ED

megadeth2600

Pinside member

Pittsburgh, PA

10y 49,550 728 46 6

What's the power consumption of the complete 128x32 panel like? LED displays can draw a decent amount of current (typically in the "all on" case) ... you might not be able to simply splice this into the power supply of a pin.

It's not at all hard to add a supply to a pin that is capable of driving an array of LEDs, but you should check that out and see if it might be a problem as I think it could tax the 5V rail on many pins . If you power a pin and it happens to drive a lot of "full on" pixels due to trash in the display driver at power up, you might get into a case where the pin will constantly reset itself .

Nice work by the way ... I am sure they look amazing in person!!!

0

#44 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from megadeth2600:
What's the power consumption of the complete 128x32 panel like? LED displays can draw a decent amount of current (typically in the "all on" case) ... you might not be able to simply splice this into the power supply of a pin.
It's not at all hard to add a supply to a pin that is capable of driving an array of LEDs, but you should check that out and see if it might be a problem as I think it could tax the 5V rail on many pins . If you power a pin and it happens to drive a lot of "full on" pixels due to trash in the display driver at power up, you might get into a case where the pin will constantly reset itself .
Nice work by the way ... I am sure they look amazing in person!!!

Yeah, they take a lot of juice. I think if it was stuck on full white it would be like 7Amps although these are driven way below 100% duty. You definitely don't want to hook them to your pin's 5v supply.

0

#45 8 years ago

ABC

Crash

Pinside member

12y 141K 14,138

Have you noticed any flicker at all with the dimmer pixels? What's the range of duty cycles from dim to full bright?

0

#46 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Quoted from Crash:
Have you noticed any flicker at all with the dimmer pixels? What's the range of duty cycles from dim to full bright?

There's no flicker, the LEDs are being strobed insanely quickly. In the TZ example the DMD information is coming in at 120Hz, and that's the rate it's outputting as well. It works a little like a huge lamp matrix in that the lines are strobed, so only 2 are actually active at any time, and it's outputting 12bit color, so there are 4 updates of varying length each row before it moves on. So a dim pixel is actually only on for 1/(120 * 16 * 16) = ~0.000033s at a time (1/256 of each frame). A fully on pixel would theoretically be on 1/16 of the time but in practice it's less than that.

0

1

#47 8 years ago

JOE

lucky1

Pinside member

Karlsruhe

8y 61,050 1,091 16

OP
Quoted from ecurtz:
Did you order from those guys and get the 2.5mm panels? I'd be nervous about the weird description.

Yes I ordered there but haven´t received them so far.

OP
Quoted from ecurtz:
Looking at his project those are smaller panels, so I think even with the extra CPU you're going to have a hard time pushing enough data for one of the big Sega displays. I haven't looked at the datasheet for one of them though, so there may be some tricks to help.

Since there is a pindmd2 version which can drive these panels and my board uses the same cpu, I still think it should work.

0

8

#48 8 years ago

OP

ETC

ecurtz

FAST Pinball

Olympia, WA

12y 56,400 725 2

Updated video with the final column bug fixed and a hideous palette applied by request of winteriscoming and Crash.

0

#49 8 years ago

ABC

Crash

Pinside member

12y 141K 14,138

Looking great!

0

#50 8 years ago

MJO

Mocean

Pinside member

11y 75,050 1,367

Any thoughts on a VGA connector so I can support this in PyProcGameHD? If not maybe there's something else I can work into the HD branch to make it easier to do color on these on P-ROC?

Post expo, I want to play with this... Let me know how I can help.

By ecurtz

8 years ago

Topic Stats

You

Find in topic

Linked Games

Topic Gallery

Reply

Hey there! Welcome to Pinside!