SynthFrog » microchip

babyBotte repackaged!

aris — Mon, 03 Nov 2008 21:49:00 +0000

This is the new babyBotte. I decided against the cardboard shoebox and dumped it. So I got a TRIPP container set from IKEA at first for putting the babybotte on the small square one and an 8MHz avrSynth I have lying around, inside the bigger one. My wife gave the idea of putting the babyBotte inside the round one.. So, I designed a panel that I would print on photographic paper and stick it on top of the lid and open holes to it to insert the pots

The small holes are for the square buttons. I used a high speed cutter to make the rectangle cuts.

Also, because the box was a bit high to grip it easily, I marked it at about the middle and cut it with tin scissors (the TRIPPs are made of a rather thin aluminum sheet)

and then I cut the rectangle holes:

To align the holes with the printed layout, I printed a draft, black and white copy of the layout and stuck it on the lid. Then, using that as a guide, I opened small holes which little by little I opened them to the diameter of the pot shafts (10mm in my case).

The layout of the buttons and the panel “design” is available at the file repository (here) .

Then I opened small holes on the printed paper and alligned the holes while letting the glue set.

Using an exacto knife, I opened the holes on the paper

and put pots and switches:

The (still) tricky part was to mount the led. I fixed it with hot glue. It is a bit flimsy but I do not intent to take the babyBote v2 to any live gigs.

So the finished bb was something like that:

or like that

The samples still remain the same as the bb survived the move.

The only thing that remains to be seen is the durability of the photopaper..

Shoebox fractalSynth

aris — Thu, 30 Oct 2008 07:35:00 +0000

This is how fractalSynth looks like:

And this is how it sounds (a little tape delay added)

I had once stumbled upon Catweazle’s fractal synth. In the circuit benders forum it seemed that the project had come to a halt. But recently I realized that it was going on elsewhere.! Here.
Also, the files can be found in the forum or in http://www.gjcp.net/~catweazle/PICsynth/
There are two schematics and lots of mp3 samples if you want to hear how it sounds.

I decided against building a PCB in eagle and then etching, soldering, etc. and went for the perfboard. It is a very simple schematic and I pulled through it with relative ease. Just remember to leave a little space around the MicroChip so as to put the simple filter and the voltage stabilizer (a simple 7805 with two capacitors, nothing special).

The schematic mentioned 10K pots but since they are used as simple voltage dividers you can go (as I did) up to 100k with no apparent malfunction. I used a lot of female pin headers on the board (as you can see) and connected the pots and buttons with male pin headers. This is rather flimsy as a connection. You might not be able to go live with such a thing but, it is quick and easy.

The underside of the perfboard is all connected with solder. A difficult to correct method but again, it is quick and I can’t wait

I used a cardboard box because it was the only thing I could find around me at the time. I had some aluminum panels lying around but I would make noise and the kids would wake up. I have mentioned again the problem I have, making panels for my stuff.

Now I have a noisemaker in a shoeBox

I added a simple voltage stabiliser with a 7805 and two electrolytic capacitors and fed the voltage to the chip.

The pots were mounted on the cardboard (a tedious and dangerous job because the cardboard was thin and there is always the risk of ripping it appart.) and soldered with wire and pin headers.

Some special attention was given to the 7-segment LED that connects to the chip. I used 150 Ohm resistors instead of 200 Ohm mentioned in the schematic. The difference is not a big issue. (It would be if 10 Ohms where used for example). The resistors where directly soldered on the led pins because I wanted no other things than the led on the top side of its board in case I wanted to glue it on the cardboard.

So it looked like this:

The whole thing was put in the box after determining which pin of the led went to which pin on the chip. This made the wiring a bit of a rat’s nest.

So the final “product” was firmly closed to hide the ugliness of it’s interior.

The first tests were a reality.. And it WORKED!!!!!

The next step was to figure how it was working.!!

A big thanks should go here to Catweazle (you can find him in electro-music.com forum) for releasing the source code as well as the schematics. I put a programming header on the board so as to try some things myself.

The next thing is to put the shoeBox fractalSynth through my MC 909 and make a tune out of it !!

A dsPIC33 breakout box.

aris — Thu, 23 Oct 2008 11:49:00 +0000

Made this in order to test the samples I (again) got from microchip… (coolest guys in the world.. If I ever make something sellable in huge numbers with a microcontroller, it will surely be a PIC .

I include the brd file of eagle so you can make it yourself (it is tested that it works). If you want you can print the bottom layer on a laser printer and then iron the paper on the back side of the board so you can have the pinouts printed on the top side..

files as always here

Serious Programmer

aris — Thu, 23 Oct 2008 11:22:00 +0000

At least more serious than the one I had before.. The pickit2 from microchip (I felt guilty for all the free samples I got so I bought the original, but there are clones on, you guessed it, e-bay!!!). It can program a much wider range of chips, namely the 16Fxxx and 18Fxxx and also the 24Fxxx, dsPIC30Fxxx and dsPIC33Fxxx (and the PIC32 but I never got to try it) . The good thing on these chips is that the dsPIC33 have Digital to Analog conversion on board at 16bit and can go to more than 110KHz sampling rates. MUST-TRY!!!!

SMD!!!!!!!!!

aris — Thu, 23 Oct 2008 11:18:00 +0000

A (failed) experiment: I got 18F6621 samples from microchip.com (I LOVE these guys!!) and they are packaged in a TQFP64 package (a very dificult to use package if you are not a machine) so I decided to make a breakout box. Get those pins in pin header format so I can stick whatever I want to them. But I failed miserably. The design was haunted by the 8mil distance between the legs. It proved more (less) than my etching method could handle so I had heavy crosstalk between the leads.

And the soldering was no easy job too!!!!!

But if you feel adventurous, there are brd files you can use to despair on your own