laser-synthitar from a guitar-hero-like toy guitar

Step 2 Schematics

The schematics should be correct but I made them after i built it and that was the first time i used eagle. Normally I put part of the circuit on a breadboard, test it and if it works i solder it on the perfboard. I recommend you to test it first too.
Its simpler than it looks. The 555 is wired as an astable multivibrator. The tone can be tuned with the 100K pot that are connected to the 555. The Wires from the fret buttons are going to the control voltage pin. The pin is pulled up to V+ by the 10K Resistor and the fret button pulls it towards GND, raising the pitch. The amount is controlled by the 100K pot connected to the fret button. So every fret can be tuned individually.

UPDATE
added schematics for parts of the circuit and simplified overview for better understanding

Comments

[king7pin7]

Hello, just wondering what type of photodiode you used/recommend for this project?

[Virtual Adept]

Do you have larger images of the schematics? I've been trying to get a better view of the oscillators, in particular how they're hooked into the laser triggers, but the image is blurry enough that I can't make out how they're patched together. I've been trying to figure it out for a week but haven't had any success yet.

[datenkrieger]

sorry for that but if you click on the "i" on the top left of the image and then "original file: (809x445) 12 KB" you get the original GIF file in full size. It gets blurry when it's resized automatically, but the original file has all the details. Basically the trigger is connected to the reset pin of the 555. I found that the laser trigger circuit is not working reliably when the 9V battery is not brand new. I recommend to swap the 10K resistor and the 500K pot so it can be adjusted better (pot can be another value) but i have to test it yet. I will post the changed schematics soon.

[Virtual Adept]

Hey - thank you, I missed that. Much better! That makes sense. I'll give it a shot in the lab this week. I'll hunt through the parts bin at the lab and see what pots I can dig out. Maybe there are some hidden in there that'll work better. I'll let you know what I come up with.