Random Music Box

Microprocessor organ and servo drum play an endless song.

From the column DIY: Music

By Kevin Weekly

Photos by Sam Murphy

Part. No. Value Estimated Price
C1 10uF $0.07
C2 1uF $0.07
C3 20nF (203) $0.02
C4 100uF $0.08
J1 .1" headers $0.10
R1 50K smd pot $0.50
R2 50K smd pot $0.50
R3 50K smd pot $0.50
R4 10K $0.01
R5 10K $0.01
R6 10K $0.01
R7 4.7K $0.01
R8 10K $0.01
R9 10K $0.01
R10 10K $0.01
SP 8ohm spkr $2.49 (radio shack)
U1 OPA4342 $2.27 (digikey)
U2 PIC16F685 $2.58 (digikey)
DIP Socket 14-pin $1.29
DIP Socket 20-pin $0.69
Servo (optional) HS-422 $15 (hobby shop)
Protoboard or Breadboard $5  
Cardboard   look around
Total   $32

Some notes about the materials:

C1, C2, and C4 are minimum (you can replace them with higher valued caps)

The requirement for the potentiometers R1, R2, R3 is that they are the same value. They can even be replaced by equal-valued resistors.

U1 can be replaced by any equivalent op amp, such as the cheaper LM324

The servo can probably be different, but I cannot guarantee another servo will recognize the PWM commands. I tried the HS-325HB servo and it did nothing but twitch.


Links

Join the conversation -- every MAKE article has an online page that includes a place for discussion. We've made these RSS and Atom feeds to help you watch the discussions: subscribe.

View our sites
Craft Maker Shed Store Maker Faire Make: television


Important please read

Search the pages of MAKE

Raves for MAKE!

“Now we've got geek DIY (do it yourself) porn. Just as would-be Emerils pore over lushly illustrated cookbooks with recipes involving hard-to-find morels and complicated instructions for roux, Tom Swift wanna-bes are devouring MAKE.”
— Steven Levy, Newsweek

“...O'Reilly Media recently launched what has already become the bible of this new movement, a magazine called MAKE.”
— Daniel Roth, FORTUNE

“If you're the type who views the warnings not to pry open your computer as more a challenge than admonition, MAKE is for you.”
— Rolling Stone

“One of the most innovative magazines I've seen in a long time.”
— Steve Riggio, CEO Barnes & Noble

“The kind of magazine that would impress MacGyver”
— Marcus Chan, San Francisco Chronicle


More Raves for MAKE

Subscribe

Subscribe to MAKE Magazine!