Archive for the ‘Grinch’ Category

A Small Detour

Thursday, March 19th, 2009

I had every intention of working on the remaining Ren24s tonight, but a pleasant surprised arrived in the mail today. Let’s rewind a bit. I may or may not have mentioned that I ordered two Grinches. Once was for me to control individual super bright LEDs, directly off the Grinch. The other was to control the lights at the store should I decide to do so. I am hoping to use the LEDs as DIY strobes, that I am planning to put in the hedges out front. The initial issue I was having was that the Grinch is run off the parallel port, and the maximum run on a parallel port is like 25′. So I couldn’t get the grinch out by the hedges, so the only alternative was to run 16 CAT5 cables out to the hedges from the Grinch that would be kept nearby the computer. I didn’t really like this idea either, seemed like a waste of CAT5 and would be unwieldy.

I started researching what my options were to extend the Grinch outside. There appeared to be only two: The RenT/RenC combo or a DMX converter. I thought hard about it and decided to go DMX because ultimately I would like everything to run DMX eventually. I initially found RJ’s DMX converter which was only on/off no dimming. This was perfect for the strobes because they would just be on/off. Turns out RJ had only made a couple of boards and had no plans to make any more. I then found RPMs Grinch Dimmer which I ended up building and it works great, but still seemed overkill for the LED strobe project and it would be perfect for at the store (I would need another DMX dongle, but luckily I ordered two PCBs, just need to get the parts if I go that route). Anyhow, while poking around at DLA, I found someone who had an extra board of RJs original design. He said he would give it to me for the cost of postage if I promised to “pay it forward”. Seemed like a good concept to me. He warned me though that he thought there was a mod that needed to be made to make the board work. I asked RJ and the others and no one seemed to remember the mod. I figured I would give it a go anyhow, so I told him to send the board.

That was a few weeks ago, and I hadn’t heard anything from him, so I figured he got tied up and forgot about it. I didn’t want to bug him because he was basically going to give it to me, and I don’t like to pester about free things. Today the board arrived in the mail. I looked it over and couldn’t see anything glaringly wrong with it, so tonight I populated it (I already had the parts from a previous Mouser order). The only thing I could find that was close to being mod like, was the BOM didn’t include fuse holders or a fuse on it. So I did what any man would do, I said “We don’t need no stinkin fuses”, and I soldered a wire across the fuse pads on the PCB. I hooked it up to my DMX dongle and the grinch with a test SSR, and it worked, first time. I think I’m getting better at this soldering thing!

So now I have the ability to control my strobes, I just need to figure out how I’m going to configure them and wire them. I’m leaning towards putting 4 LEDs in some sort of epoxy, and they would be controlled from 1 CAT5 cable, so I would have 16 strobes, each with 4 individually controlled LEDs within it. We’ll see how that pans out later.

Now we’re dimming!

Tuesday, February 24th, 2009

My DMX dongle PCBs arrived today. I was rather excited to get one soldered up so I could test out my DMX Grinch Controller. It only took about an hour to solder it up, quite a testament to RJ’s design. Anyhow, I plugged it in, fiddled around with some settings and voila, I had [smoothly] dimming lights. I guess now I’ve got blinky, flashy, dimmy. They definately look a lot better when dimming. I’m so glad I went with the renards so that my whole display can dim. When I signed up for the renard coop, I had very little knowledge about what I was getting myself into, but I think they will end up being a good decision. I kind of wish I had gone with something that spoke DMX natively, but the renards are supposed to speak DMX with different firmware, so I might have my cake and eat it too!

My whole Grinch setup minus the SSRs

More dimming than last time, but still not quite there.

Thursday, February 19th, 2009

As promised, I threw a MAX485 on a bread board and hooked it up to my Arduino. You can use the USB driver on the Arduino board and hook the TX pin into the Arduino, combined with the Entec Open USB DMX driver, you can easily and cheaply spit out DMX. Anyhoo, I hooked that circuit up to my Grinch DMX Dimmer and fired up Vixen and started spitting out some dimming channels. Indeed I had some dimming Christmas lights, but it was very jumpy and there was some random flashing going on. It surely wasn’t smooth, but at least it proved that my DMX Dimmer was getting a signal. I’ve been reading that the Open DMX (which has no “brains”) has a hard time keeping up with the timing for the DMX signal (like .4us) because the computer is doing all the work. I’m hoping that when my DMX Dongle PCB gets here and I get it built up, I will have much better results. It will have a dedicated controller for keeping the timing just right and the computer will just have to say “hey you, turn on channel 1 at 50%”, and it’ll politely do so.

I put together another SSR, and had much better success this time, maybe I’m actually getting the hang of this soldering thing. I had two of the triac joints bridged, but that was easy enough to fix and at least I didn’t fry anything this time. I still have 14 more to build, but I’m not in a huge hurry. The Grinch and SSRs will probably end up at the store anyhow, as I should have enough channels (for this year) with my Ren24’s. Speaking of which, the PCB’s are supposed to be arriving Friday, so hopefully I’ll have mine next week. The heat sinks are due in March 2nd, so by mid march I would imagine I would have at least one running and in its enclosure that I can post some pics. I found a bigger enclosure than the 9×9 ones I was going to use, it should let me have more room to play with for putting a grounding bar in and some strain reliefs in.

Most of this week so far I’ve been trying to teach myself Assembler on the PIC so I can use one as a standalone show controller, (and perhaps for other projects… cough… cough… wireless barcode scanner). I have been able to send data to my ShiftBrites for now, but am trying to figure out the best way to put a “show” on there. At least it’s progress I suppose. I’ve also been trying to find music that I like and that will be appropriate for my show. I’m also trying to get a feel for the beats and what would look good with it. I probably won’t start sequencing until I nail down the layout of everything, and that won’t happen until it warms up enough to measure out parts of the house. I hope to get going on sequencing soon though, because from what I have read, it takes most people 4 to 5 hours+ per song, and that’s if you know what you’re doing.

Dimming Grinch… Sortof

Monday, February 9th, 2009

I got my Dimming Grinch DMX board assembled last night. The backordered terminal blocks finally arrived from mouser last week. I got it all together and checked it over for bad joints and powered it up. Right off the bat, the LEDs were acting really flaky. They would come on and go off randomly. It also seemed that when I would touch certain places on the board they would react to that. I thought great, I’ve got a bad joint somewhere or a broken trace. I couldn’t find anything. Turns out that because they are connected to the AVR and it hasn’t been programed yet, the pins are set as inputs as the default. Being inputs, they were just turning the LEDs on willy-nilly and can be influenced by outside electrical noise, which apparently is what my body was inducing when I would touch the board.

Anyhow, when I tried to program the chip with my usbtinyisp, I got nothing. I screwed around with it for a while, and eventually built up a programming circuit on a breadboard to try it out outside of the PCB. Sure enough, first try, the programmer found the chip. OK great, I went to set the fuses and got the lower fuse set fine. When I tried to set the higher fuse, nothing. I couldn’t find the chip again. Well since I had set the chip to use an external clock when setting the lower fuse, it was expecting an external clock and my circuit didn’t have one. So back to the PCB I went, because it has an external clock. I screwed around with it for a while and ultimately gave up. Today after reading the schematic, I realized that pin two of the ICSP header wasn’t connected to anything and since pin two is where the chip gets Vcc from the programmer, I knew I wasn’t going to fry anything if I left the programmer’s self powered jumper on. I tried it and BAM! it worked.

I’m thinking that when I removed the header, neither Vcc nor ground was getting connected, and the grounds needed tied together to make the circuit and the programmer “become one”. So, I got the fuses reprogrammed and flashed the program onto it and we appear to have one working dimming grinch DMX board thingy. Only missing part is the DMX. I’m planning tomorrow night to hook a max485 to my arduino to make a pseudo DMX dongle that I can at least test my dimmer with.

I might just have dimming Christmas lights tomorrow night and my Ren24’s aren’t even here yet!

Robert Martin's Dimming Grinch DMX Controller


Saturday, February 7th, 2009

Here is a copy of the post I just made on DIYC for my own archival purposes:

I finally have blinky flashy!!! Thank you everyone for all of your help and suggestions. I had my grinch working with LEDs to test it, but tonight for the first time, I have blinking Christmas lights.

The original problem with the SSRoz was that channel 3 wasn’t working. It turns out that it was just a bad joint at R7 so the opto for channel 3 wasn’t getting 5V. However, that naturally wasn’t the first thing I checked and ultimately led to all of my other problems. I did however learn several very important tips that I will have to keep in mind as I proceed to build the rest of my SSRs and my Ren24s.

1. Don’t get too excited.
Once my back ordered resistors arrived from Mouser yesterday I was dead set on getting some blinky flashy on. Because of this I probably pushed my self way to much once things started going wrong. I should have just went to bed. This leads to #2…

2. Don’t try to troubleshoot at 12:30 AM (unless of course you’re usually up at that hour, which I am not)
I made some stupid mistakes last night because I was tired and just wanted the thing to work. Namely I left the grinch plugged into the SSR while trying to troubleshoot it and I believe the cable moved it too close to a spiral notebook that I had on my table and this shorted out the Allegro’s on the grinch, thus leading to the previously working channels on the SSR to stop working. I ended up frying the Allegros, but fortunately I had two spares to test it with and the spares fired right up.

3. Don’t assume it is just one thing.
Turns out my fuse holder wasn’t quite soldered on right. The joint looked good, but it wasn’t. This was leading to some of the flaky behavior I was experiencing. This in combination with the joint at R7 and frying the allegros started leading me in the wrong direction.

4. Don’t assume anything.
Once those faulty joints started misleading me, I started thinking that I somehow fried the optos or the triacs. Tonight, after I fixed my grinch with new Allegros, I went back to the SSR, channels 1, 2, and 4 were working again, 3 was still not. I put one of the good optos in and still nothing, so I assumed it was the triac. I spent the better part of a half hour de-soldering the triac and putting a new one in. Sure enough this didn’t fix it either. This is what ultimately led me to the bad joint on R7.

5. Make sure the AC is plugged in.
I don’t know how many times tonight I unplugged the AC cord to swap something around and went to try it… then nothing. Within a few seconds I would realize the AC was still unplugged but it was still annoying.

6. The blinky flashy is SOOOO worth it.
I was getting pretty frustrated last night, but I should have just walked away and went to bed. Tonight when I had four strings of lights at my feet sequencing, it’s hard to describe the feeling, but I’m sure you all know it.
My first two completed SSRoz's