View Full Version : Using FPP with a Grinch

12-17-2015, 05:40 PM
I have primarily been a consumer of information on this site, but have decided to give back to help others who may be in a similar situation. First, thank you to all of you who actually design the products and software that make all of this possible. I have been successfully using a Grinch connected to an old tower PC running XP with Vixen 2 for 8 years now. I almost didn't put my lights up because I was losing interest, primarily because I'm limited by available real estate, and I was getting bored with the same set-up year after year. But this year I discovered the pixel forum and subsequently FPP running on a Pi. This has reinvigorated by interest in Christmas lights, and I plan on switching over to pixels next year. All that said, I will have a Grinch, 16 SSR's, and 48 strands of perfectly good LED lights that would just be sitting in a box unused. So as not to waste all that soldering time, I decided I will want to use all of that stuff at a secondary location, but without having to drag around the cumbersome PC tower and associated peripherals. Enter FPP running on a Pi B+.

I searched the forum and wiki, and even the Falcon site, but wasn't really able to find a concise answer to my question since interest in the Grinch is all but dead. But I found enough to be dangerous. So I pass along to all of you who have Grinch's laying around, since it's such a great little controller, should you want to continue to use them. I am not taking credit for this solution, just consolidating it in one place.

Obviously you need a Pi and you need to install FPP (plenty of other resources to help you do that).
You will need 4 GPIO cables. I was able to find a 40 Pin GPIO ribbon made by Stellar Labs at Microcenter that has individual plugs, rather than a solid 40 pin block (picture attached). So I was able to separate 4 of the wires. Then cut the plugs off of one end. The next step might not be to "code" but you have to file down the wire insulation about 1/4" so that the wires will slide into an RJ-45 plug. Don't expose the wires as you might get a short. Using the diagram in the Grinch Wiki, connect your wires to slots 3, 5, 7, and 8 in the RJ-45. Ignore the DB25 part of this diagram.


Under the Help Index in the FPP software there is a section for the Channel Outputs. At the bottom under the GPIO-595 section, it shows how to plug your wires into the GPIO on the Pi. It's kind of confusing if you've never dealt with GPIO, like me. I chose to use BCM 17, 18, 27. If you're unfamiliar with the GPIO pins go to this link.


As you can see the GPIO pins are numbered funny. At the top of that page is the BCM numbering, and towards the bottom of the page is the physical numbering. So BCM 17 = Pin 11, etc. In normal guy language, if you are holding the Pi like in the diagram, BCM 17 and Pin 11 are the 6th metal pin from the left on the bottom row. What the help file in FPP does not mention is that you need to connect a ground wire. Like a good soldier I followed the directions to a T, and my lights were blinking all wacky. After connecting the ground, it works perfect. This may be obvious to most of you, but this post isn't for you. So connect as follows:

RJ45 slot 3 - to GPIO ground (I used Pin 14 since it was closest to the other 3 pins I was using)
RJ45 slot 5 - to GPIO BCM 17/Pin 11
RJ45 slot 7 - to GPIO BCM 27/Pin 13
RJ45 slot 8 - to GPIO BCM 18/Pin 12

You can also use GPIO BCM 22, 23, and 24 if you want, but you can't use both.

I have attached a picture of my finished cable attached to my Pi. Yes, I know my green wire is not on the ground pin, but it worked easier hooking up the wire the way they were stuck together. So, do as I say, not as I do. Or do as I do as long as you know green isn't always ground because sometimes yellow wants to be.

And if you're like me you have to convert any Vixen 2 files into the .fseq format to be used in FPP. I used Vixen 3 to do this, and yes I was totally lost in V3 having used V2 for 8 years. But after reading the Vixen 3 documentation on their website, V3 makes sense to me and I look forward to using it for pixels. When setting up my sequence in V3 in the Controller Setup, I created 64 channels (maximum allowed on a Grinch) even though I only patched 48. Not sure if that makes a difference or not, but it worked.

One final step. In FPP, under Input/Output Setup, select Channel Outputs, then select the Other tab, Add a GPIO-595. Set Start Ch. to 1 and Ch. Cnt to 64. (I assume if you run daisy chained Grinch's that the Ch. Cnt number would be higher). And the Output Config select 17-18-27 or 22-23-24 depending on which pins you used. Save, restart FPP, and you're done.

I assume all of this would work for any Olsen-595 controller, but I don't have any of those so I can't say for sure.

I know that was long, but I hope it was helpful to someone who may be lost trying to figure out how to use some of this stuff. I know I would be lost, and I'm sure I will be when I start playing with pixels, if it wasn't for all the helpful people on this site. Thanks again.


12-17-2015, 09:11 PM
Thanks for the writeup. I'm glad you were able to use the older controller with FPP. One of our goals is that the program can easily be used by people with 1 channel or 100.000 channels. I will update the help page to mention the ground wire. I already have a TODO item to update the GPIO pin help notes to be easier to follow.