Introduction: DIY Mini Bass Synth : Meeblip Anode
This is my first instructable on building the award-winning monosynth : meeblip anode, from scratch.
Bellow is a video from musicradar showing you the possibility of this synth.
It is a fully open source hardware bass synth, which is made to give you fat bass sounds, via midi control.
If you want an other quick presentation on it and a sound example of what this device can do, check out the manufacturer site : meeblip.com.
Although you can buy it, i think it is way more interesting to build it yourself as it is an open source synth, (hardware and firmware are on GitHub)
So, let's get started!
Step 1: A Little Bit of Research
First, let's take a look at the source files,
ALL THE FILES NEEDED ARE ON GITHUB.
I decided to make the circuit on stripboard (or veroboard). I find one website who just shows the stripboard version of the schematics on github : irieelectronics.de.
So thanks a lot to Paul on this website for his stripboard design. I know his files are copyrighted and i do not owned the copyrights, but i just wanted to share his great work with you. So thanks a lot to him for understanding. :)
The first picture is the stripboard layout, with PCB traces cuttouts symbolized by red dots.
For the case, i designed the layout with Boxmaker and then edit it in Photoshop. I provided you the PSD files, feel free to use them as you like. (i can't give you a jpeg copy because instructable compress it too much to see the lines on the layout :( . )
Step 2: Gathering Components and Materials Needed
B.O.M. : (from irieelectronics.de again) : Bill Of Materials (R12 isn't specified, but it is 100 ohm).
You will need an isp programmer like this one, to upload the firmware to the atmega32.
For the enclosure, i used a sheet of 3mm MDF (wood) from my local hardware store.
Step 3: Start Soldering !
Prepare the board : First, cut the stripboard with a bit according to the red dots on the layout.
Solder it : You need to install the two wire (+5V & GND) under the atmega32 before soldering it.
Then, solder the components on the stripboard according to the layout and the Bill of materials to know which components are referred to which numbers on the layout (like R2, C7, etc...).
WARNING! There is one error in the stripboard design, the first green jumper wire on the left is connected to BL (x;y) although it should be connected to BK. Make sure you do not fall in the trap.
Step 4: Firmware Programming
To burn the firmware on the atmega32, you first need to download the firmware folder on GitHub.
You can see detailed instruction on how to do it HERE.
I'm just going to give you the headlines on how to do it with the isp programmer listed before (make sure that the drivers are installed correctly, you can fin useful infos on that by searching on Google.)
Install WinAVR (for windows) (to allow the computer communicate with the atmega trough the programmer) : Link HERE
Open the file "make-anode.bat" in the firmware folder, and change the name after "-C" to the name of your isp programmer. Mine is "usbasp" so here is my file :
avrdude -c usbasp -p m32 -B 5 -U flash:w:anode.hex -U lfuse:w:0xBF:m -U hfuse:w:0xD9:m pause
I added the command "pause" at the end to prevent the console to close herself after process is done, that way you can see if the process went successfully or failed.
Then connect the programmer to the computer and the pins to their right spot on the stripboard. (black spots left to the atmega, names are in blue on the left on the picture.) Take attention when doing it, if you plug it the wrong way, you may destroy your atmega32 !
Then, run the file "make-anode.bat"
Done ! Firmware flashed on the microcontroler ! :D
(If it fail, make sure that you have the correct drivers installed, the correct isp programmer name, the "firmware" folder with all the others files in it, good connection on your circuit, and the AtMega out of the circuit (put it on a blank breadboard just to program it) and well connected to its 16Mhz crystal on the proper pins.)
Step 5: Making the Enclosure
I printed the enclosure layout (see PDF layout attachment in step 1 ) and glued them on a sheet of 3mm thick MDF. Then i cut all around the traces and glued the "panels" between them. Don't glue the top one or you wont be able to open it to place electronics in there ! :p
I painted it black after sanding the case.
Step 6: Mounting the Pots and Wiring Them
First, place the panel-mounted components on the side and wire them according to the layout.
Then, place the pots and switches on the top panel according to the second layout, and wire them to the stripboard.
I added little knobs to the pots.
(Credits : layouts are from irieelectronics.de, i added connections names to the second one for better understanding )
Step 7: Mounting the Switches and Others Connectors
Mount the switches and the midi jack, the audio jack, the midi-learn button and the DC-power jack.
Then you can wire them according to the layout.
Step 8: Wiring Everything
This step is a bit messy. I added connectors to the pcb to be able to disconnect the top panel easily.
Step 9: Time to Make It Pretty !
I printed some design on some labels, then cut and stuck them on the case.
You can download the pdf file if you also want to print it.