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MeeBlip project

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

Step 1.
Start off with the PCB
retro meeblip
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)
Install mcp6002

Step 3.
Add the two 25V(or better) 10uF electrolytic capacitors, this has to be orientated correctly, reference the stripe on the case
25v 10uF

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 Trim leads

Step 5.
Add the two 470 electrolytic capacitors 470pF

Build tip.
Splay the leads to hold the parts whilst you solder, as the parts will heat up very quickly
Splay leads

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.

Lead forming tool

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
100 ohm

Step C.
Add the 0.001uF capacitor( may be marked as 1000pF which is equivalent)
.001uF or 1000pF

Step D.
Add 10.7k Resistor

Step E.
Add 274K resistor

Step F.
Add 1K Resistor

Step 10.
Add 10K potentiometer ( volume )
10k pot
To make it mechanically stronger, add solder on all four sides of the metal tab, top, bottom, left, right.
Solder both sides

Step 11.
Add 1/4" audio jack
1/4 audio

Step 12.
Add 3.5mm audio jack
3.5mm jack

i wanted to test the audio signal noise levels here as our first meeblip had some noise
Power, scope and signal source added
Testing the amp

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

right side output, left side input
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
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.
Straighten legs

Step 14.

Install ADC7302

Step 15.

Add the ATMEGA32, take your time, straighten the legs. These chips can be hard to come by.
Atmega32, straighten pins before install
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
10k and 22pF's

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
ISP Header

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)
Diodes and dip

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.
1N4148 diode

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
Led. I used a blue 5mm

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.
x0xb0x and meeblips

sonofablip.txt · Last modified: 2013/08/13 12:13 by