Simple Sequencer

One of the keys to making good music is mindless repetition. That is what the simple sequencer is great at. It does the same thing over and over again in an eight note sequence. You can adjust the frequency of the note, the duration of the note and the pause between notes. If you get really good, you can anticipate the next note and change things up on the fly. This little box is sure to provide endless hours of fun.

You will need:

- (8) 1M potentiometers
- (8) 50K potentiometers
- (8) 10K potentiometers
- (8) SPST 5V relays
- (1) 20K potentiometers
- (16) .1uF capacitors
- (16) 220 ohm resistor
- 74HC595 Shift Register
- Lamp pull switch
- Power jack
- Mono audio jack
- 10K resistor
- 16F877 Pic chip
- 20 MHZ resonator
- PCB or two
- 40 pin socket
- Mat board
- 12 x 12 sheet of acrylic
- Wood grain contact paper
- 5 x 7 aluminum box
- An analog variable resistance based noise maker
- Rubber feet
- 26 knobs of various color
- A power drill
- C-clamps
- A laser cutter
- A soldering setup
- Misc tools and hardware

(Note that some of the links on this page are affiliate links. This does not change the cost of the item for you. I reinvest whatever proceeds I receive into making new projects. If you would like any suggestions for alternative suppliers, please let me know.)

Stick your wood grain contact paper onto a sheet of acrylic. Lay it contact paper down inside the laser cutter.

Cut the acrylic with the following file and raster cut it with the following settings:
Passes: 5
Power: 100
Speed: 100
DPI: 600

After you are done raster cutting, vector cut using the following settings:

Power: 100
Speed: 10
Frequency: 5000

Cut out some mat board spacers on the laser cutter using the file below.

The setting I used for the vector cut were:

Speed: 100
Power: 40
Frequency: 2500

Attach wires to the left leg and the center leg of the 1M, 50K and 10K potentiometers.

Now is time to assemble the top panel.

For each potentiometer, slide on a mat spacer and then install it through the back such that the notch on the potentiometer is aligned with the indent in the back of the acrylic.

In what you figured will be the top row, insert the 1M potentiometers.

In the middle row insert the 50K pots.

In the bottom row insert the 10K.

Following the schematic posted below and build the circuit.

This will require using a fair amount of circuit board. I used two from Radioshack. On one I put the PIC chip and the 7805 regulator (and a relay I ran out of space for). On the second board I put the relays and the shift register.

I built as much of the circuit as I could and then I added the potentiometers and lastly wired it to the audio circuit.

I didn't wire up things that would need to be installed in the side of the case like the power plug and the volume knob. For testing I temporarily included a 9V battery adapter.

Using the files below, laser cut a mounting bracket, 1/4" spacers and a cork liner.

To vector cut the acrylic I used these settings:

Speed: 10
Power: 100
Frequency: 5000

To vector cut the cork I used:

Spedd: 100
Power: 50
Frequency: 1500

Fasten your circuit board to the base panel with nuts and bolts. Don't forget to sandwich in between the 1/4" spacer to give the circuit boards some elevations.

Neatly hot glue the cork base to bottom.

Program the 16f877 chip with the following code and then transfer it into the socket.

CPU = 16F877
MHZ = 20
CONFIG = 16254

SI con A0
SCK con A1
RCK con A2

abit var byte(9)
nDur var word(8)
nP var word(8)

counter var byte
setValue var byte
noteDuration var word
notePause var word

'shift register address bits
abit(0) = %10000000
abit(1) = %01000000
abit(2) = %00100000
abit(3) = %00010000
abit(4) = %00001000
abit(5) = %00000100
abit(6) = %00000010
abit(7) = %00000001
abit(8) = %00000000

'duration array pins
nDur(0) = D0
nDur(1) = D1
nDur(2) = D2
nDur(3) = D3
nDur(4) = D4
nDur(5) = D5
nDur(6) = D6
nDur(7) = D7

'pause array pins
nP(0) = B0
nP(1) = B1
nP(2) = B2
nP(3) = B3
nP(4) = B4
nP(5) = B5
nP(6) = B6
nP(7) = B7

counter = 0
setValue = %00000000

main:

for counter = 0 to 7
HIGH nDur(counter)
pause 1
RCTIME nDur(counter),1,noteDuration

setValue = abit(counter)
gosub out595
pause noteDuration

HIGH nP(counter)
pause 1
RCTIME nP(counter),1,notePause

setValue = abit(8)
gosub out595
pause notePause * 3

next

counter = 0

goto main

out595:
shiftout SI, SCK, LSBPRE,[setValue\8]
pulsout RCK, 8
Return

Hook up power and make sure that it works. If it doesn't work:

- Check all of your connections. Make sure none are crossed and none are missing
- Make certain the PIC chip is in the socket properly
- Turn the main volume knob. The sound could be down.

Drill holes in the aluminum case to mount your volume dial, audio jack, pull switch and power plug. Also drill out some holes so that you can here the speaker.

I wanted to match the holes already on the speaker, so I rubbed permanent ink on the speaker and while it was still wet, transferred this to white gaffers tape and stuck this to the case as a drill guide. I then drilled.

Cut a sheet of contact paper large enough to fold over onto all sides of the case with 1/4" to spare. In the corners, cut diagonally outwards so that you can fold them in.

Line the rest of the case with contact paper. Don't yet peel away the backing for the last 1/2" around the edges as you will need to keep this sticky to glue on when you glue the case closed.

Cut out holes where you will be installing your jacks, knobs and whatnots.

Securely fasten all of your hardware to the aluminum casing.

Discover that your audio jack shorts your circuit when it is installed in the casing. Cover the hole for the audio jack with contact paper and drill a hole in the top piece of acrylic to install the audio jack. Install it again.

Put your circuit boards in there. I glued the audio board to the inside of the case. The main one I just let sit on the bottom as there are so many wires attached to it, it is not moving anywhere.

Double check to make sure that your circuit works one last time and then hot glue and/or epoxy the case shut.

Peel the remainder of the backing from the wood liner and smooth it out onto the case.

Press on all of your knobs and dials.

Stick some adhesive rubber feet to the bottom so that it doesn't get scuffed up.

Turn the knobs as your heart desires and make some mighty fine pseudo-repetitive music.