Step 1.
Start off with the PCB
I'm building this Audio end first, because I wanted to look at the noise levels.
Step 2. Add the MCP6002 Op Amp ( The flickr site has tags for the location of components)
Step 3. Add the two 25V(or better) 10uF electrolytic capacitors, this has to be orientated correctly, reference the stripe on the case
Trim the leads close as you can, hold on to the leads that will be removed as they'll fly off, or use clippers with a built in catch
Step 5. Add the two 470 electrolytic capacitors
Build tip. Splay the leads to hold the parts whilst you solder, as the parts will heat up very quickly
Step 6.
Add a 0.01uF capacitor Build tip.
Pre bend the leads before inserting, find a suitable block of something. I used a small wooden brush to bend the leads to the correct width and shape before inserting into board.
Step 7.
Add the 1M resistor
Step 8.
Add the 0.1uF capacitor, you can also add it to the other locations at this point.
Step 9.
Add the 4.64K resistor
Step A.
Add the 23.7K resistor
Step B.
Add the 100 Ohm resistor
Step C.
Add the 0.001uF capacitor( may be marked as 1000pF which is equivalent)
Step D.
Add 10.7k Resistor
Step E.
Add 274K resistor
Step F.
Add 1K Resistor
Step 10.
Add 10K potentiometer ( volume )
To make it mechanically stronger, add solder on all four sides of the metal tab, top, bottom, left, right.
Step 11.
Add 1/4" audio jack
Step 12.
Add 3.5mm audio jack
Testing.
i wanted to test the audio signal noise levels here as our first meeblip had some noise
Power, scope and signal source added
The device on the right is an Arbitrary Waveform Generator, it basically can generate just about any signal that we need, sine, square, pulse, triangle, noise and any recorded signal (the arbitrary part) The Device on the left is an oscilloscope
We can see the signal is the same, except amplified on the right
Input signal. I'm feeding the op-amp a 10kHz sine wave with a 0-1Volt range
The scope is showing the same sine wave, 10.0001kHz but the amplitude is greater
A little slice of chaos
Step 13.
Add another 10K Pot
Build Tip.
Very carefully straighten the legs of all the DIP packages, they're always slightly splayed for machine insertion. There are some tools to do this at NSL, but its easy. Ground yourself first, then just lightly put pressure on one side of the part onto a hard, flat surface.
Step 14.
Install ADC7302
Step 15.
Add the ATMEGA32, take your time, straighten the legs. These chips can be hard to come by.
You can also preprogram the chip before installation with the EEPROM programmer at NSL
Step 16.
Add the 16Mhz crystal
Step 17.
Add the 10K resistor, and the two 22pF capacitors
Step 18.
Add the 0.1uF decoupling capacitor
Step 19.
Add a 0.1uF decoupling capacitor
Step 1A.
Add the ISP programming header, 6 pin IDC. We use this to upload new code into the CPU
Step 1B.
Add the 10uH inductor, its slightly wider than the width of the holes.
Step 1C.
Add the 1N4001 diode, this is for reverse polarity protection (you plugged in the power backwards).
Step 1D.
Add all the 1N4148 diodes. These are for the switch matrix
Step 1E.
Add four more 1N4148 diodes (switch matrix) and the 4 switch DIP (midi channel select)
Step 1F.
Add Switches ( controls) You might another pair of hands to hold these in as they're soldered on.
Step 20.
Add another 1N4148 diode with two 220Ohm resistors.
Step 21.
Add 1.2K resistor.
Step 22.
Add the 5.6K resistor
Step 23.
Add the optocoupler (midi)
Step 24.
Add the LED, I used a Blue 5MM but it ought to be a red 3mm. If you change the colour the resistor below should be correctly calculated
Step 25.
Add a 0.1uF capacitor
Step 26.
Add 10uF electrolytic capacitor, orientation matters, check the stripe on the side of the can with the - symbol
Step 27.
Add the LM7805 regulator, the part number will be vary but it will have LM7085 in it
Step 28.
Add a 0.33uF capacitor
Step 29.
Add the remaining 10K pots, solder the metal tags on both sides
Step 2A.
Add the USB connector
Step 2B.
Add the MIDI DIN connector
Step 2C.
You're done!
Step 2D.
Program the CPU with the ISP if you haven't already
Get AVR studio from Atmel or boobies
Connect up an ISP programmer and use the following settings for the AVR Programmer mode Clicking 'Read' should give you the values you see here
Program fuses (important or nothing works!
Step 2E.
Plug it in and make noise Some of the settings won't make noise, and you'll need a MIDI source.
