Introduction: Crazy Looper

About: Brian McNamara is an experimental instrument builder and sound sculpture artist based in Bungendore, NSW, Australia. Brian mixes his passions for music, electronics and sculpture into unique objects that shou…
The Crazy Looper is a small hand held device that allows you to create real-time noise loops with a fast modulation metallic effect. It's a simple microcontroller project that I give an easy to build rating.

If you want one that is ready to play, you can buy one here:

These instructions will give you all the info you need to build a crazy looper, Schematic, software file etc. I got the circuit board made but you can easily use vero board because it's such a simple circuit. 

Step 1:


1 x 100nF Capacitor  (C5)
1x  10nF Capacitor   (C6)

2x  10k Pot(spline shaft)  (VR1 VR2)
2x  10K Resistor (1/4W)  (R2 R4)
4x  1K Resistor (1/4W)  (R6 R7 R8 R10)

1x  Regulator 78L05 (5V)  (IC3)
1x  Ic Holder 8Pin  
1x  Picaxe 08M  (IC2)
1x  3.5mm Socket(stereo switched) (SPKR) 
2x  LED (RED)  (LED1 LED2)
2x  Knob (Grey) 
1x  Battery Holder(9v) 
1x  Circuit board 
1x  LDR(10M)  (SW1)
If you don't have a picaxe programmer or programming cable you will need to get on try SPARKFUN

Step 2: Resistors and Wire Link

*Solder the 4 1K(R5 R7 R8 R10) and the 2 10K(R2 R4) resistors to the PCB.
*Solder in the wire link at S2.

Step 3: IC Socket

Solder the 8pin IC socket to the PCB

Step 4: Audio Connector

Solder the 3.5mm audio connector to the PCB.

Step 5: Capacitors

Solder the capacitors(C5 C6) to the PCB. 

Step 6: LDR

Solder the LDR to the PCB. Make the LDR sit about 8-10mm from the PCB.

Step 7: LEDs

Solder the LEDs(LED1 LED2) to the PCB. 

Step 8: Voltage Regulator

Solder the voltage regulator(IC3) to the PCB.

Step 9: Variable Resistors

Fit the 10k variable resistors VR1 and VR2 to the PCB.

Step 10: 9 Volt Battery Clip

Solder the 9 Volt battery clip to the PCB.
*(optional) At this stage you can add some hot glue to the spot where the leads attach to PCB to stop the wires from breaking.

Step 11:

Fit the two knobs to the variable resistors.

Step 12: Program the Micro

Now we need to program the Picaxe micro-controller.
The basic program file is attached below and the programming editor for the picaxe can be downloaded for free at the revolution education website. Here :

You have two hardware options here, you can use a programmer like this Sparkfun or build the programmer into your circuit. If you build the programmer into the circuit the crazy looper becomes the programmer. I have included the circuit for both in step 14.

*Open the Picaxe programming editor and load the file "crazy looper 2010_04_16 v1_21.
* Connect the computer to the programmer via the programming cable. 
* Fit the picaxe 08m to the programmer.
* Run the programmer by pressing F5.
*You should see a progress bar and then a dialog box, that says the programming has been successful.

Step 13: Fit the Picaxe

Fit the Picaxe 08m(IC2) to the PCB.

Step 14: Crazy Looper Schematic

I have included two schematics, one is the circuit without a programming port and one includes a programming port.

Step 15: How to Use

The Crazy Looper builds up sound loops using three controls,tempo, sound and write.

The sound control adjusts the frequency of the tone in the second half of the dial and the level of noise in the first half of the dial, giving two distinct sounds. The first half of the sounds have some spots that are blank to cut the sound up as you move the control up and down.

The second control is Tempo, which controls how fast the loop is played. Write the loop at a slow tempo then speed it up for a great effect.

The third control is the write LDR, when you put your finger over the light sensor it writes a sound to memory, which is then replayed next time the loop cycle starts. With the sound control knob adjusted clockwise, you can add a rest to the loop by pressing the Write button.