From Null Space Labs
Building a Meeblip (original)
=== Introduction ===
=== Sounds like ===
Meeblip bassline demo by cdm
MeeBlip: The hackable digital synth - SOUND DEMO by cdm
Modulations by cdm
=== Looks like ===
Although we have no current plans to use cases, this is what it would look like with one
Costs like -:
Around a £Bullseye
Bulk buy has brought down costs, and we're working on a few avenues to bring it down more
Handy Resistor colour code template
Build Log of Meeblip #2
Start off with the PCB
I'm building this Audio end first, because I wanted to look at the noise levels.
Add the MCP6002 Op Amp ( The flickr site has tags for the location of components)
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
Add the two 470 electrolytic capacitors
Splay the leads to hold the parts whilst you solder, as the parts will heat up very quickly
Add a 0.01uF capacitor
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.
Add the 1M resistor
Add the 0.1uF capacitor, you can also add it to the other locations at this point.
Add the 4.64K resistor
Add the 23.7K resistor
Add the 100 Ohm resistor
Add the 0.001uF capacitor( may be marked as 1000pF which is equivalent)
Add 10.7k Resistor
Add 274K resistor
Add 1K Resistor
Add 10K potentiometer ( volume )
To make it mechanically stronger, add solder on all four sides of the metal tab, top, bottom, left, right.
Add 1/4" audio jack
Add 3.5mm audio jack
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
Add another 10K Pot
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.
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
Add the 16Mhz crystal
Add the 10K resistor, and the two 22pF capacitors
Add the 0.1uF decoupling capacitor
Add a 0.1uF decoupling capacitor
Add the ISP programming header, 6 pin IDC. We use this to upload new code into the CPU
Add the 10uH inductor, its slightly wider than the width of the holes.
Add the 1N4001 diode, this is for reverse polarity protection (you plugged in the power backwards).
Add all the 1N4148 diodes. These are for the switch matrix
Add four more 1N4148 diodes (switch matrix) and the 4 switch DIP (midi channel select)
Add Switches ( controls)
You might another pair of hands to hold these in as they're soldered on.
Add another 1N4148 diode with two 220Ohm resistors.
Add 1.2K resistor.
Add the 5.6K resistor
Add the optocoupler (midi)
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
Add a 0.1uF capacitor
Add 10uF electrolytic capacitor, orientation matters, check the stripe on the side of the can with the - symbol
Add the LM7805 regulator, the part number will be vary but it will have LM7085 in it
Add a 0.33uF capacitor
Add the remaining 10K pots, solder the metal tags on both sides
Add the USB connector
Add the MIDI DIN connector
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!
Plug it in and make noise
Some of the settings won't make noise, and you'll need a MIDI source.