8 posts tagged “circuit bending”

Continuing my project from last year's design seminar, I've bent a Yamaha PSS-270 keyboard. A lot less hassles this time, and much better results. I'm probably going to give most of the credit to the new soldering iron I picked up. See, the difference with this one from the Radio Shack models I'd been using beforehand is that it actually works.

Anyway, the work began with basically un-doing everything from last time. So I cut all the spaghetti out and started removing the wires that somehow hadn't already come unattached on their own. I realized that one good thing about using crappy irons before was that I got a lot of consequence-free practice on the circuit board. Everything I messed up basically just fell right off since the new solder never really got hot enough to bond with the original manufacturer stuff.

I apologize for some of the off-color, blurry camera work you're going to see if you click on any of these photos, my poor little Cyber-shot is starting to show its age lately.

Before:

After:
You can see in that last one how many of those wires just popped off after a gentle tug. I went with the soldering iron to get the rest off the board. Some of the wires were still pretty solidly soldered to the switches however, so I just cut them down and used a wire-stripper so I could just attach the new wires to them and not have to work around them.

Ready for a second try:

With the board all cleaned up, and the switches still attached to the frame and ready to go, it was time to get started on connecting everything. Along with purchasing the Xytronic iron, I also got a roll of ribbon cable to use instead of that heavy-gauge coat-hanger wire Radio Shack stuff from the previous try. It worked great, it was much more flexible and everything stayed a lot more organized. With the new iron and better wire, attaching everything to the circuit board was surprisingly easy and I was done relatively quick.

First row attached:

And the second: Next up was hooking up the switches. In my infinite wisdom, I had just plopped them all into the frame last time, and about half of them ended up being oriented upside-down. I had to go through and map everything out with a meter to see which ones were which, you can see my little diagram here:
(okay, I just re-read this bit and I'm not sure if this is actually what I did or not, but I'm leaving it)
In the end, I decided it would be easier to just hook wires up to whichever side would make the switch work as if it was aligned properly, instead of going in and pulling each one out and re-positioning all of them. I'd already gone through the trouble of mapping them all out anyway and pulling them out could be tough since it's sort of a tight squeeze in that area. Kind of a backwards way of doing things, but whatever, it all worked out:
With everything connected, it was time to close it up and try it out. The LCD lit up on power-up, and I actually got a nice slow hum out of it pretty quickly without too much effort. Success!

Once I got the hang of working it, I took a series of samples - the nicer ones can be found here, at my website (just scroll down): click

Notes / To do list:

• mess around inside it some more - now that I've got it somewhat reliably working, I'd like to go in and look for some more bends and maybe add some photocells to it. Also, it should be possible to get the keyboard to work normally as well as bent, so I need to check my connections and see what's going on with that.
  
• fix the power switch - as far as I can tell, I lost a tiny plastic ball bearing out of the on/off slider, so turning it on can be a bit of a hassle since it doesn't snap into position anymore. Maybe I can find a decent replacement? Make some sort of work-around?
• install a 'reset' switch onto the power supply - been meaning to do this since last time, just need to get my hands on a power drill. it is possible to "hang" the thing if you get really adventurous with it, and it tends to start up more easily if you take out the batteries and flip the power switch a few times, so a switch to save time on that sort of thing would be handy.
• take more samples
  
• get a new digital camera, ugh

Made an awesome discovery this morning! The keyboard works! Sort of!

Usually, once about every ten times you turn it on, it'll respond to some ham-fisted button mashing and then crash. Playing with it throughout the day yielded about fifteen seconds of playtime at the best session, but later today I got it to stay on long enough to make about ten minutes worth of recording. Have a listen to these three, probably the more exciting ones of the batch.

So yeah, I'm happy. I won't be able to get anything major done in time for the due date, but now that I know the chip isn't ruined like I thought, future plans for the thing are basically undoing everything and starting over. There's at least one loose wire in there somewhere and it'd be more work to find it and fix it and whatever other ones are loose, so I'm going to start over with better materials. I need a better soldering iron and smaller gauge wires, as first priorities. At Chad's advice, I think I'm going to add an extra power switch directly to the battery line, see if maybe that will make it a little less temperamental, maybe clear out something in there that might be keeping it crashed whenever its turned off normally? Not a hard addition to make, I'll see if I can do it soon.

Aw, dammit. I bricked it. You can turn it on, then the LCD counts up from 17 to 31. Thats it. No noise, nothing. I am really really disappointed...

Why did it die? Not sure, but I can guess: I blame my bad soldering skills. I may have even overheated it and let the magic smoke out as I put a wire on the last pin. Tried a couple things to get it going again, but nothing works at all. A sad day, indeed.

Just spent the whole night working on hooking up wires and switches to all the pins on the chip. After getting all the switches attached, I repositioned the circuit board and mounted the switches to the case. A little sloppy, but the rack inside the case that holds the keys in place kind of put a squeeze on a couple of the switches, and those threw the rest out of them 'out of whack' (yes, that is the scientific term there).

Unfortunately, when moving everything around I realized a two things I had suspected all along: my solders aren't very good, and the wires I had been using were too short. So nearly a third of the wires pulled themselves out while I mounted the switches, but I went ahead and mounted all of them anyway, just to get it done. However, now my switches aren't all oriented the same way - some point up to turn off, some point up to turn on. Also, I need to go back and re-attach all the dang wires that came off. It'll take a little bit of poking around with the multitester to figure out where all the pairs are, but I think after that, it won't be too hard to get the switches all organized correctly.

I'm so burnt out, hopefully the keyboard isn't... calling it a night now, I'm tired, my fingers are sore, my back hurts from hunching over, and my eyes are kind of burning from all the noxious fumes. If I have the energy after work, I will finish this all up tomorrow, and then we'll have the moment of truth and see how this thing turns out. One good thing - I've kind of convinced myself that my biggest worry (the chip overheating) won't happen, because my soldering iron can't even get hot enough to melt the original solder spots on the circuit board (which is why I'm having such a hard time soldering), but its good because I think I'm safe so far as heat goes. We'll see. I'm pretty sure I haven't let the magic smoke out yet...

PS: There's no images here yet, just place holders. I know. I just got a new computer and it doesn't have a card reader like my old one, so I have to dig up the USB cord for my camera before I can get any photos uploaded on this thing. Hang in there.

Earlier today the main thing I was waiting on - a package of tiny switches I ordered from allelectronics.com - came in the mail, miraculously right on time. I was worried these would come later next week and put huge time constraint on the project, but that crisis is averted now, thanks to the good ol' USPS. I picked up a multitester to check the data lines later and a set of tiny screwdrivers from Home Depot. I already have plenty of wire, solder, etc. The keyboard itself came from goodwill for about five bucks, so it's a little funny that the switches by themselves cost two or three times more than the instrument itself.

Opening the case and getting the board out is easy, no weird things there. I didn't even need my new tiny screwdrivers. I'm almost disappointed.

Cleaning out the case with some compressed air, I found two dead roly-poly type bugs in the speakers. What the heck? I figure they're probably from sitting around in somebody's garage for years before being donated to goodwill.
Okay, time to get down to business. I start the actual bend by cutting the data lines as instructed by the tutorial. This is actually not too hard, just a couple careful scrapes with an X-acto knife. A quick check with the multitester, tells me I've successfully cut the lines.

Now I start soldering wires to the FM chip. Here's where things get messy. I am not good at soldering. I have a crappy soldering iron. These solder spots are tiny. My heart rate is way way up. I probably take an hour trying over and over to get wires to make good solid connections to the pins. By the time I finally have a good system going, the tip of my soldering iron is too burned out to work on the really little spots on the bottom row. I want to keep going but I don't want to risk screwing up those tiny spots and seriously ruining the whole project. So I'm calling it quits for the night - I need a new tip for my soldering iron, mine has corroded away to a big melty stump at this point. My biggest worry right now is that I've already overheated the chip with my horrible soldering skills. This is turning out to be a much more stressful project than I anticipated.

Starting today I'm working on bending a Yamaha PSS-270 following this tutorial for my BFA seminar. This is going to be my most involved circuit bending project so far, I'm a little anxious. Hopefully I can A) not fry the damn thing B) not accidentally kill myself somehow and C) get sounds out of it that are at least half as cool as these.

Here's a quick description of the project as gleaned from the circuitbenders.co.uk forum:

the data stream mod, when in place works like this....

the 8 toggle switches you've put in which connect the data streams, when all of them are on, do nothing. the keyboard should be the same as normal...

now, when you turn one or a few (i wouldn't do all of them at once) of the switches to the off position and then change patch, press a key or two and then turn them all on again. you should hear a patch which has parts of the former selected sound in it. chances are it will be a bit more random than you expect. eg, you can't think, hmmm, i'll mix a piano patch with a string patch. well, you can, but the bends don't seem to be the same every time.

it's also worth noting that whilst any of the data streams are off, the keyboard can exhibit 'crash' type tendencies where the keyboard won't track pitch or make a sound at all, sounds will only play when three or four keys are pressed etc. the drums get a bit, er, funky too.

Sounds like fun, eh?

Well it's pretty much go time over here for the BFA thing tommorow... gonna try to wake up early and go with a friend who's also applying so we can get spots next to each other, and in a good location (gotta beat the crowd). Then I'll have to run over to the copy shop and get a couple posters printed out that I forgot about today... really hope I wake up on time.

I wanted to get another little circuit bending project done in time for the entrance, I ended up with a jerry-rigged little thing that I didn't really even do anything to. It was originally a little toy harmonica thing, I took it apart and found that if you just mash the area the buttons touch with your fingers it'll freak out from the inaccurate body contacts (or something like that) and then you can manipulate it a little further with a knob that was originally built in to control the tempo of the sound clips. It does sound cool, though, and I hooked up a 1/4" jack to it so I can record some stuff later, but I am a little disappointed that it's not any more impressive than it is. I relocated it into a new, bigger casing and its all melted holes and rubber bands right now, kind of pathetic. But I figure having a couple bent toys might help me stand out from the crowd a bit? I don't know anyone else doing it at school.

Saw Spoon tonight, they had a good show but their two boring-ass-one-man-and-a-guitar opening acts can bite me.

Also, while running errands and picking up art supplies today I realized that I am really really close to being completely broke - moreso than I thought, that is. My bank account has kind of gone from bad to worse in this last week. Which sucks since I've got to pay the cable bill soon. But we get paid early this week because of the holiday Monday, so hopefully I'll have enough on my check to cover me for the next week at least - my last check was a total joke. Maybe after this BFA thing I'll see about picking up extra hours on Tuesday and Thursday mornings before school. I'm not 100% worried, I've got a good deal of savings hid away as backup, but I'd really rather not have to use them. We'll see.

Anyways, off to bed after I finish a drawing here...

Alright, here we go:

Named her Shelley after I used a Scary Go Round sticker to patch two holes I drilled for the switches before I realized the battery case wouldn't let them fit. Absolutely proud of this thing, its a blast to "play" and it's loud as hell. This was actually a pretty simple little bend, I didn't want to get too ambitious with it, so I only added one knob and two switches; however, by some weird stroke of luck, the original volume knob becomes a fourth variable when either switch is engaged.