Circuitbenders Forum
Circuitbenders Forum => Circuitbending discussion => DIY Synths => Topic started by: Circuitbenders on February 04, 2008, 06:45:00 PM
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what happened to your Fraktal/CellilarAutomata Synth?
http://www.circuitbenders.co.uk/forum/index.php/topic,424.0.html
now that seemed like an incredibly cool device. Weren't you making some PCB's at one point?
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Hi,
how about that:
I post all you need to build it as DIY project
All you need is a few components:
- Microchip PIC 18F4620 (you can get it for free (sample) at microchip.com)
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1335&dDocName=en010304
To put the software(hex-file) into the microcontroller you need a "programmer"
- ProgrammerHardware for programming the PIC microcontroller:
http://www.semis.demon.co.uk/uJDM/uJDMmain.htm
Software for programmer:
http://www.winpic800.com/index.php?lang=en
all is freeware!
(you don't need programming knowledge for building it)
source code (c language) and compiled hex file for the uC
will be posted here tomorrow.
and you need ... (things a bender has already)
- some Resistors and capacitors
- potentiometers and switches
- 5Volt source (7805 voltage regulator)
- breadboard or pre-drilled pcb
It's not that complicated ... have a look :
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Luckily i just ordered a PIC programmer so i will definately be having a go at building one of these whan it arrives.
Can't wait to get this thing up and running
What are the values of the pots at R3 to R6 etc?
Is JP1 a connector block and if so do you really need it if the PIC has already been programmed? I don't have much experience with PIC's as yet.
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Thank you for your interest! I'm very motivated to continue the project.
sorry I forgot that pot values.
The values for the 8 Potentiometers are not critical, use 10k Ohm Pots.
JP1 is the connection for the programmer (ICD = in circuit programming)
You do not have to remove the PIC for programming.
And very IMPORTANT:
the 100nF capacitor should be placed near as possible at the PIC !
(between pins 11/12 or 31/32), don't forget to power pins 11/12 AND 31/32.
The schematic is the minimum requierd. I want to keep it as simple as possible.
But enough for the beginning. I don't think a ready made PCB is really needed.
Of course we can add some switches, LEDs etc but then some more components needed...
I thoght long about selling ready programmed PICs, but what about software updates then.
If you have a programmer you can do updates yourself.
Ordering a ready made programmer is a good idea (you know that thing is working).
For my opinion the
http://www.winpic800.com//index.php?option=com_content&task=blogcategory&id=19&Itemid=88
is a good choice because it can burn PIC , AVR and EEPROMs. And 60€ is not much for that feature.
But there are also cheaper ones available (look for "ICD" or "PIC programmer" on google ...
There are a lot other interesting PIC/AVR projects on the www like MIDIbox, SwinSID, AVRsynth etc...
So it's nice to have a programmer for PICs and AVRs ;)
(the PIC and AVR microcontrollers are nearly the same, it's kinda religion which to choose)
If you not shure about the programmer you have found feel free to ask me.
(the PIC18F4620 should be at least supported by the programmer!)
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Here is the Schematic for Version 1.0 for the Synth Hardware.
Bill of materials:
- "Veroboard/Stripboard" PCB - or Breadboard
- PIC 18F4620 40 pin DIL package
- 40 pin DIL IC socket (if you don't want to solder the PIC directly)
- 8 potentiometers (linear) 10k
- 1k Resistor
- 4.7k Resistor or 5k pot
- 10k Resistor
- 10nF capacitor (0.01uF)
- 100nF capacitor (0.1uF)
- 100uF capacitor (35Volt)
- 10uF capacitor
- 0.1 .. 10uF capactor (audio output)
- Diode 1N4007 or other general purpose
- 7805 Voltage regulator
- 5pin pin header 2.54mm grid for programmer connection
- Plug for external wall wart power supply or battery holder ...
... and some sorted length of wires
Software follows...
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and here is a little demo of what you get ...
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICSynth_Demo1.mp3
the sequence at the beginning is the dry signal out of the pic synth.
i hadn't tweaked any knobs while recording. The sequence and tones came out of a "chaos algorithm"
at 6 seconds I added delay (digitech x-series digital delay) and filter(Korg MS20 filter unit).
I don't know where the regular plops in the mp3 came from (maybe software bug or simply chaos itself ;)
No samples where used what you here are only two 8bit counters and some very simple math.
see link for more details about the algorithm theory and idea behind ...
http://www.instructables.com/id/Predictive*-digital-music-synthesizer-Pandora_s-B/
and here is another demo ... (same setup but more tweaking).
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICSynth_Demo2.mp3
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Just got my PIC programmer from somewhere in hong kong via ebay. It appears to program any PIC's up to 40 pin and EEPROM's. It also has a handy 6 pin connector so i can plug it straight into the PIC-synth board. Not bad for just under $10.
If anyone wants to make one of these synths in the UK, the only place i've found that stocks the PIC18F4620 in the UK is JPR electronics HERE (http://www.jprelec.co.uk/index.htm?http&&&www.jprelec.co.uk/docs/order_code.asp?pCode=%5F21T0YEGKO&PGID=%5F0G20ZQO8M&LEVEL=1&SearchType2=3&MODE=&PARTNO=&KEYWORD=&PG=Semiconductors&RELATED=0&rtype=A&OC=NONE&TEMP=NONEl)
If anyone knows of elsewhere in the UK let me know.
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I#m actually quite tempted to have a go at making one.
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If you can't find any distributor for the PIC18F4620, try DigiKey, Mouser ...
or you can get free product samples from microchip.com if you register and have a little time.
*****
News:
*****
Software (HEX-File for the PIC) is ready (beta version) for download:
If you want the source-code (ccs c-compiler) mail me acidliner<at>web.de
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_Betaversion.zip
Fraktal Synth Software (beta version):
Pot Description
---------------------------------
1 Algorithm 1..4
2 Speed / Pitch
3 Parameter 1
4 Parameter 2
5 Parameter 3
6 <not used yet>
7 <not used yet>
8 <not used yet>
Parameters 1..3 are depending on the algorithm.
Parameter 3 is only used in Algorithm 3.
Algorithm 4 is not working yet (available in next update)
Smal changes of the parameters can make big differences in the tones and sequences.
I'll keep you informed about software updates
the algortihms can be more powerful ...
and some pictures of my prototype
Tip:
If you build that thing in a box make a hole for the ICD programming interface.
The 7805 voltage regulator can be very hot. Mount some "cooling metal plate" on it.
Connect a LED (with 1k series resistor) to the 5V power supply to see if the power supply
is working right.
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wow that looks / sounds bloody great! :)
nice one!
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thanks for the feedback.
each of the demo mp3 shows only 1 posibility what this thing does.
I don't have tweaked any knobs while recording, only a external filter and delay fx were used.
To make it a bit more exciting.
New Software version
Betaversion02.hex
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_Betaversion02.hex
I have modified the first two algorithms from the first betaversion in order to make them more controllable.
Algorithm 1 fraktal synth,
has 65535 posibilitys/different tones and sequences
Algorithm 2 fraktal synth,
has 255*255*255 tweak settings... (different modulations than algorithm 1)
Algorithm 3 is preliminary, not very exciting
Algorithm 4 cellular automata, a bit buggy yet, but will be fixed
I'm planing to implement that "4 oscillator sleepdrone synth" as algorithm 3.
(that thing build up from ttl/cmos buffers used as oscillators modulating each other)
from Nicolas Collins book "Handmade Electronic Music: The Art of Hardware Hacking"
... and some new demos ...
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICSynth_Algorithm_1.mp3
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICSynth_Algorithm_2.mp3
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Both those new demos are briiliant, especially the first one, instant acid techno!
Its annoying that JPR won't have any of the right PIC's in stock until Feb 25th, i'm not sure i can wait that long, with any luck the samples i ordered will have arrived before then ;)
What are you planning for the remaining knobs?
Some way of sync-ing the thing to an external clock input would be the most useful thing i can think of.
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I was a little scared as I heard what comes out of the box the first time ;D
Remaining knobs:
Knob Description
------------------------------------------
1 Algorithm selection 1..4
2 Speed/Pitch
3 Parameter 1
4 Parameter 2
5 Parameter 3
6 Parameter 4
7 Parameter 5
8 Parameter 6
some algorithms will use all knobs (in the release version). I have added 8 knobs to be flexible, ok some are
not used but I'm shure we find something to do with the unused ones ;)
It's better to have some left for future ideas (updates).
For example I have combined the first two algorithms in one (7 knobs are used). Since they are
pretty the same (mathematically).
Sync:
mmmh... a bit difficult .... but should be not impossible
timbre and sequencer are not created seperately (how it is done normaly) all result from only one algorithm.
To tell the truth I hadn't thought about that a lot. But you are right that would be a good feature.
I finish the 4 algorithms first and then I have a look how to do sync.
MIDI (clock) sync?
I hadn't thought it is so diffucult to get the PIC18F4620, here is another possible distributor
http://www.voti.nl/shop/summary.html
or
a list from the MIDI-Box project
http://www.midibox.org/dokuwiki/where_to_order_components
Of course other PIC18Fxxx work for this project, too. But I don't want to rewrite the code
for all possible PIC types available :P . I hope you understand that.
But if it is really difficult to get the PIC18F4620 we can talk about using another more
common available type.
Why I have choosen the 18F4620:
- lots of flash memory 64kByte (place for sample storage or something)
- lots of RAM memory 4kByte
- I had it already at home ;)
I'm shure we could find a good distributor for the PIC...
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PIC synth update: New Algorithms
- Step-sequencer (8 step) with FM-tonegeneration... I discovered some TB-303 like stuff,
no filter or other external equipment was used!!
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICSynth_Fm-Stepsequencer.mp3
(step sequencer is controlled via two knobs one for step the other for the value at selected step)
- Second algortihm redesigned ...
external filter and delay was used.
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_NewAlg2.mp3
... I don't want to go onto your nervs with all that demos,
it's only to keep you informed about the project state...
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No demo's are good! There's only one thing that matter.... how it sounds.
And it sounds bloody amazing... why is that? what is it, 8 bit sound or 1 bit or what?
Thinking of building it aaahhh!!!!
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No demo's are good!
surely you mean:
No, demo's are good!
;)
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surely you mean: No, demo's are good!
;)
... why is that? what is it, 8 bit sound or 1 bit or what? Thinking of building it aaahhh!!!!
Why?
- There are a lot of cool schematics and "lofi" synthboxes out there. But most are to expensive or to much
components to wire (I'm a bit lazy). Lazyness, it's much more easier to do a program code than wiring
a lot of ICs and analog parts. And if something has to be changed the circuit has to be rewired, software is
easier and quicker changed. Belive me, it's really much more easier to learn a programming language like "C"
than learning all about electronics. Today every cheap PC has so much performance to do all the stuff we
build in software (VST-plugins, Max/Msp, Reaktor). But is it really fun to play a VST-CrackleBox with the mouse?!
So the intension was an cheap easy to build versatile and bendable hardware platform.
Next thing is that it's a bit boring to implement/rebuild the well known stuff again and again
(the hundreth crackle box, ataripunkconsole ...).
There are a lot of interesting fields we can get our ideas from: chaos theory, cellular automata,
algorithmic omposition, neural networks, fuzzy logic and nature.
- 8bit/1Bit:
Sound is calculated with 8Bit resolution, the PIC-microcontroller works internally with 8bit wide data/registers.
Sound is outputed via pulsewidth modulation (PWM), which is 1Bit output but 8x oversampled.
At the moment, you get 4 different synthesizers/noisemakers in one microcontroller/box.
- Two fractal based "music" generators ("predictive digital music synthesizer", it's not random!)
- Step-sequencer (8 steps) with FM(frequency modulation) tone generation
- Cellular Automata (1 dimensional, see "game of life", "critterandguitari")
But the synths are not limited to 4, it can be more (8,16,32 .. 2^x), A lot of free space is left in the PIC.
ToDo / Ideas:
- adding some switches (Play/ReTrigger, Reverse/Forward, Synth/Preset and Store/Rec)
- adding presets for each synth
- adding a Audio input for use as a FX/Sampler
- adding a 128kByte EEPROM (25LC1024, SPI) for sample storage
- adding MIDI input (control, sync)
- adding more synths (why not some common stuff)
I hope I don't have to write a detailed users manual because my english is not good enough to write
a good detailed and comprehensive manual. Ok, if the thing is working right (one algorithm is still in development)
I post of course a overview of the knobs and algorithms.... but no "high gloss" high resolution color magazine.
I'm shure you can build and bend it ;)
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ok, sound says more than thousand words - here is another wired FM-Stepsequncer demo.
The sequence itself is a bit shitty I know, but shows some of the posibilities. lofi fm-madness 8)
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICSynth_Fm-Stepsequencer_%232.mp3
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No demo's are good!
surely you mean:
No, demo's are good!
;)
Got carried away and forgot the comma... :)
At catweazle: Man that thing sounds good.... Supergei!l
Glad you're not writing plug-ins but doing some funky hard/soft combination.
Will have to look into building your machine... list of projects is growing....
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... list of projects is growing...
oh yes, that long list with no end :D
Here is a PICsynth demo tweaking the fraktal-synth algorithm. bleeps and blops
recorded without effects (but it really need external effects and experience playing it live)...
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_Algorithm1_Tweaking.mp3
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well i've finally got the parts, now to find time to actually build the thing ;)
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***********************
* PICsynth Betaversion 03 *
***********************
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_Betaversion03.hex
------------------------------------------------------------------------
| PICsynth_Betaversion03.hex |
------------------------------------------------------------------------
| | Alg 1 | Alg 2 | Alg 3 | Alg 4 |
| POT | Fraktal | Fraktal | FM-Step | "WSG" |
|-----|---------------|---------------|---------------|----------------|
| 1 | select algorithm 1..4 |
|-----|----------------------------------------------------------------|
| 2 | pitch / speed |
|-----|---------------|---------------|---------------|----------------|
| 3 | xxxx.... | xxxx.... | Step 1..8 | Main OSC pitch |
|-----|---------------|---------------|---------------|----------------|
| 4 | ....xxxx | ....xxxx | Step value | AM OSC pitch |
|-----|---------------|---------------|---------------|----------------|
| 5 | yyyy.... | yyyy.... | DCA Decay | FM LFO pitch |
|-----|---------------|---------------|---------------|----------------|
| 6 | ....yyyy | ....yyyy | FM Decay | FM depth |
|-----|---------------|---------------|---------------|----------------|
| 7 | zzzzzzzz | zzzzzzzz | OSC A pitch | not used |
|-----|---------------|---------------|---------------|----------------|
| 8 | not used | not used | OSC B pitch | not used |
------------------------------------------------------------------------
I've tried to implement the WSG as software, sounds not like the original but strange anyway ;)
Since the cellular automata is a bit boring in the moment I replaced it with the pseudo "WSG".
Hope you got it working, and have fun with it.
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I'm working on it now.
assuming that the algorithm selection pot is divided into 4 bands of resistance values to select the 4 different algorithms wouldn't it be possible to use a 4 way rotary switch with 2.5K, 5K, 7.5K and 10K resistors on the pins? I'm just thinking a definite switch between settings might be a bit more useful for definite selection. Unless I've misunderstood and it actually fades between algorithms.
admittedly a rotary switch would mean that you couldn't add extra algorithms aftarewards as you'd be limited to 4, but would it work in theory?
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That's a good idea to use a rotary switch for algorithm/synth selection, better use 8 divisions
because the next software updates will contain "8" selectable synths.
And eight is the magic number in the PICsynth =)
But you have to do it this way (voltage devider):
+5V
^
*-------o A4
|
10k
|
*-------o A3
| \
10k --- o ----------> AN0 (pin2)
|
*-------o A2
|
10k
|
*-------o A1
|
---- GND
I have choosen the POT as alg/synth selector because
- less wiring pleasure
- easy expandable (number of maximum algorithms/synths)
The pot acts as an switch (rotary switch) emulation done in software.
No, it fades NOT between the algorithms, yet (but morphing would be cool on the fraktal synth)
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Tips for building:
- the case should not be to small, extensions: audio input connector, 4 switches/buttons, (midi input?)
- circuitboard should have space for a 8pin and a 14pin IC and some resistors/caps (board area > 3 x pic size)
- adding a filter http://www.circuitbenders.co.uk/forum/index.php/topic,499.0.html could be nice ;)
Check your PIC-programmers connector, it is not shure that the pinout of your Programmer is the same
as on the schematic, the pins PGD(data), PGC(clock) and MCLR(Vpp) have to be connected right.
(if they are not correct nothing will burn but not working, programmer could not detect target PIC).
Maybe you have to build an adapter cable. (MCLR,+5V,GND,PGD,PGC).
Or if the programmer has an 40pin connector for the PIC, use that instead.
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well, i've wired everything up and tried to burn the PIC with my programmer which has a 40 pin connector, stuck it in the circuit and got absolutely nothing. I'm assuming it should make some noise as soon as its turned on? How many milliamps should the circuit draw when its working?
I've checked over the board about 20 times with a multimeter and its all wired up correctly so i can only assume that i managed to burn the PIC wrong.
Is there any way i can tell if the PIC is actually working or if its actually burnt right? i used the 'verify' feature on the winpic software and it seemed to be alright and it detects the PIC alright although it seems to think that the PIC18F4620 is a 32k device where as you said it was 64k
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problem solved, it was a combination of a dead volume pot (a amateur error ;) ) and WinPic800 just not liking my PIC programmer. In the end i re-burnt it with PICPgm programmer and it works fine.
Catweazle, you are a genius, this thing is brilliant. I'm really liking the FM step algorithm at the moment although you are right, it could probably benefit from an analogue filter. Looks like i'm going to have to build another one in a bigger box!
PICPgm can be found here if anyones interested http://members.aon.at/electronics/pic/picpgm/
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I recommend putting a series of markers around pot number three to divide it into 8 segments so that when you are using the FM-step algorithm you can tell which step you are adjusting a lot easier.
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I'm glad you got it working so fast and very pleased to hear that you like it.
The PIC has 64kByte flash memory, which is organized in words (1word=16bit=2Byte)
so it has 32kWords memory. I think that's the reason why some programmer software show 32k memory.
The ouput has lots of high frequency components in it (comes from the PWM). You can add a second
lowpassfilter (4k7 resistor and 10nF capacitor) in series to the original schematic if it is to high for your needs.
It should be said that other people doing great stuff with microcontrollers:
AVR Chiptune Tracker
http://www.linusakesson.net/hardware/chiptune.php
1-Bit Groovebox ("Atari2600 emulator")
http://web.media.mit.edu/~nvawter/projects/1bit/
http://burnkit2600.com/gear/1-bit-groovebox/
PIC-Synth (mmmh, same name, I have to find another name for it!)
http://www.icb.se/araya/synths.html
6 Voice / Speech Synth based on PIC
http://oopic.com/soundgin/
Doepfer Sampler/Wavetable Osc Module A-112
http://www.doepfer.de/a112.htm
... and of course that thousands of SID 6581/8580 hardware projects.
I gain some ideas from them as well and implement in some ways. But first I want to add a
Audio Input for sampling or fx. We have to do something with the big flash memory ;)
So we can bend the unbendable (record something and bend the samples)
To make it a bit special I will use a CMOS HEF/CD 4069 (hex inverter) as input amplifier/antialiasing filter.
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Can anything be done about the way that on the FM step algorithm the step selections don't appear to be equally spaced around pot 3. Steps 1 and 8 seem to have selection areas about twice the size of the others.
The other odd thing is that the OSC A pitch and OSC B pitch knobs seem to turn in opposite directions. The pitch is higher in a anti-clockwise direction on OSC A and a clockwise direction on OSC B. Its just a minor thing but if you can easily change it that would be cool.
-
* PICsynth Betaversion03a bugfix *
- FM-Synth OSC A/B oddity fixed. Now both are change values in the same direction
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_Betaversion03a.hex
I have deleted the old betaversions, only the newest is online (prevents chaos on server and organizing it)
That pot prob (step selection) seems to be mechanical. I've printed out the values from the
PIC internal ADC(analog to digital converter) via PC RS232 terminal and measured the
real voltage on the ADC input to compare them.
There is an area on the left and right side where the values (real and adc converted) are not changing.
This problem could be removed by software (scaling with a lookup table) but this kills performance
and it depends on the pot used. Some sort of calibrating would be needed then.
... maybe we have used cheap shitty pots (I used very old ones)
... or I do a big mistake in thinking/software
Be sure that you are using linear pots, not audio (logarithmic) pots!!!
I add one 7-segment LED display next, connected directly to the PIC to show the selected step.
(http://www.unicornelex.com/pictures50/14/14-2300.jpg)
-
ok, another update and a demo of the pseudo WSG (synth 4).
The pitch/speed range of the FM and WSG synths are expanded...
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_Betaversion03b.hex
Long WSG Demo (external filter and delay ;D)
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_WSG.mp3
and a new demo from the FM-Stepsequencer (lower sequencer speed)
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_FM-Stepsequencer_%233.mp3
enough for today...
-
... maybe we have used cheap shitty pots (I used very old ones)
... or I do a big mistake in thinking/software
Be sure that you are using linear pots, not audio (logarithmic) pots!!!
I add one 7-segment LED display next, connected directly to the PIC to show the selected step.
(http://www.unicornelex.com/pictures50/14/14-2300.jpg)
I've tried it with 3 different brand new linear pops of different types and you get the same effect so i'm thinking it might be in software.
The LED display is a great idea if it can be added in.
One slight problem with the FM speed knob is that it now seems to have a logarithmic response, in that the speed difference for a small movement as higher speeds is a lot more than at slower speeds. Maybe it was always like that but because there are slower speeds available the faster speeds have all been pushed into a smaller pot rotation at the top.
-
I try to fix that with the strange scale of the step-select pot. But in the moment I have no idea.
The LED display should fix that for now.
Speed/logarithmic isue:
problem is: every pot is converted into values 0..255
that means the whole speed range is divided into 256 steps, (not much)
But you are right, the old scaling for the FM-sequencer speed was better.
here the firmware, fm speed old scale.
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_Betaversion03c.hex
-
For those who want to know what can be done with the PICsynth FM-Stepsequencer,
here is some upspeed techno stuff. (no drum-machine or other noise-makers were used)
"BassDrum" and "hi hats" result from FM modulation (and internal math errors in software).
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_FM-Techno.mp3
... schematic and software for display and extra switches is in progress, coming soon ...
-
PICsynth LED display and switches added...
Schematic:
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_V11_schematic.JPG
old schematic version (REV1.0) will no longer be supported.
Software/Firmware Betaversion 04:
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_Betaversion04.hex
-
photo of the picsynth ...
-
Thats looking good.
How do you mount one of those number LED displays, i've never had to do it before? Looks like i'm going to have to build another one with a bigger box and more space for additions on the board. Whats the plan for the other two switches?
I assume that everything will still work with the updated firmware and the play / reverse switches but without the LED number display actually installed. I suspect there will be some people that may want to build the thing but might find the display unnecessary or too complex to add. Also i'd like to update the firmware of my first prototype to the version with the switches but theres no space to mount the display in the box i put it in.
(http://img212.imageshack.us/img212/9421/fraktalhl8.jpg)
UPDATE: i had Betaversion03c loaded into mine and it started doing something weird. On the FM step synth if i set the step value and then turn the step selection knob up and down quickly all the steps become the same note. If i change the step value and turn the selection knob again all the steps become the new note. Its as if the step value knob is constantly outputting data. I upgraded to Betaversion04 and added the play and reverse switches and its still doing the same thing, maybe my pot is dying or dirty although i'm using sealed pots so it seems unlikely. It seems like it happens at random but its a bit difficult to program if you don't know if all the steps between the one you are on and the one you want to change are going to change as you pass through them. :-\
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What way round are the pots wired up on the schematic there?
Which pin is pin 1 depends on which way you are looking at the pot and there doesn't seem to be any normal way of numbering them.
-
@voodoolikeudoo:
if you look at the potentiometer, axis facing to you, then connect left pin to gnd, the right to +5V and the middle pin goes to the microcontroller (AN0..7). The schematic/layoutsoftware (cadsoft eagle) has that numbering in the libraries.
Voltage on the middle pin should rise if you turn the knob clockwise. -> see picture
@circuitbenders:
I like that transparent boxes you use!
Display:
I have simply cut out a hole fitting the LED display and then glued it with hot-melt adhesive.
The series resistors (current limiting for the LEDs) were soldered behind the display (I used small resistors).
Or you can solder the Display on a piece of veroboard and mount the board with screws.
There are little LED displays available, I found one with dimension 10mm x 8mm
The display can be omitted if not neccessary. But if used it have to be a "common anode" (CA) type !
Switches:
Play and Reverse can also be omitted, but you have to do the following:
- connect PLAY to +5V (always play) [PIC pin B5]
- connect REVERSE to GND (play forward) [PIC pin B4]
- connect the other 2 inputs to GND [PIC pins B0 and B1]
The "other 2 switches":
have no function yet. I have some ideas like a global sequencer controlling all synths for example.
But ignore them (ground them) for now if you have some keep the space for them.
Sequencer step selection bug:
oh oh, I see what you mean... really not nice ... will be fixed.
Thanks for investigating and reporting the bugs!
well, maybe a bit annoying all that bugs and extensions,
but hey, it's all free and I don't want to sell a ready made perfect (and expensive) high-end synth.
I keep in mind that I do no more hardware changes if not really necessary.
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*********
* BUGFIX *
*********
FM step selection problem:
Pot values toggle on some positions between two values, what is normal and no error.
This could be seen on the display if the Step-select-pot is "between" two steps.
The display shows a mixture of both values (flickers).
Therefor the selected step toggles.
I've tried different possible solutions to solve that.
I've used a common method often used in commercial synths/sequencers.
If you change the Step, the Step-value pot is locked.
To unlock it you have to fetch the old value with the Step-value pot.
Turn pot from left to right (or in the other direction).
If the pot-value and the stored value (old value at the selected step)
are the same the Step-value is unlocked and the Step-value-pot
changes now the selected step value.
It is a bit stressy to fetch the old value with the pot to unlock the value but
this has some advantages against other methods, and it is very easy to implement in software.
When the pots get older there could be jumps in the values (like crackling on audio amplifiier pots)
which ignores the "fetch old value"-method.
Since the performance is limited I have to implement all as simple as possible. It's no DualCore Pentium ;)
Another new feature is that the displays shows symbols for the selected synth:
Fraktal1 Fraktal2 FM-Seq WSG
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_ | | _ |_|
Here's the bugfix
http://etecnic.fh-pforzheim.de/~catweazle/F-Synth/PICsynth_Betaversion04a.hex
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Just discovered you can get some insane loops & sounds with the fraktal1 algorithm running at maximum speed and adjusting knobs 5,6 and 7. The reverse switch can turn then inside out as well.
Heres a couple of demos of full speed fraktal1 action
http://www.circuitbenders.co.uk/demos/PIChispeedfraktal1demo1.mp3
http://www.circuitbenders.co.uk/demos/PIChispeedfraktal1demo2.mp3
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Very cool, catweazel! Ill be building one very soon.
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Hi, could you please re-up the .HEX file as the link is dead. thanks x
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catweazle seems to have disappeared off the face of the planet and so has his website. He hasn't signed in here since march 27th.
I think i might have most of the hex files in a backup somewhere. I'll take a look and post it if i can find them.
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Has anyone got the demo MP3s? Does the source for the firmware exist anywhere? It would be a shame if this was lost...
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i found a link to this a few days ago. i really want to hear the sound samples but the site hasn't worked!
can i get them anywhere else?
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Hi folks,
my server is down, sorry ... but someone asked me to post the PICSYNTH in
the electro-music.com forum:
http://electro-music.com/forum/topic-25422.html
Here you can get all schematics, source and hex files.
Sound-Samples:
ahm, I still have no server, so if I have a new one I upload the samples again.
For questions and suggestions you can mail me:
Eric Boger
acidliner(at)web.de
Good luck building and having fun with it ;)
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Thanks for reminding me, i've also uploaded the construction files to the circuitbenders server if thats cool with you catweazle?
it can be found here http://www.circuitbenders.co.uk/hostedstuff/picsynth_v11_191.zip
theres some demos of mine at:
http://www.circuitbenders.co.uk/demos/fraktal/fraktaldemo1.mp3
http://www.circuitbenders.co.uk/demos/fraktal/fraktaldemo2.mp3
http://www.circuitbenders.co.uk/demos/fraktal/fraktaldemo3.mp3
http://www.circuitbenders.co.uk/demos/fraktal/fraktaldemo4.mp3
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i've also uploaded the construction files to the circuitbenders server if thats cool with you catweazle?
Yep, of course, thanks for uploading.
On the electro-music forum you can found some more sound samples from somebody else.
(should be no advertising for other forum, only a hint)
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Catweazle - mail me off-forum or pm me if you want some server space ;-)
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PICsynth plans and audio samples are available again...
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I found a place where they program the PIC for 3 Euro if you don't have a programmer.
Will be building this! Hey Catweazle any plans for Midi?
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Hi djsynchro,
any plans for Midi?
Nop :-\
I've thought about Midi Clock but I don't know how to sync the algorithms easy yet.
Parameter control via MIDI is theoretically possible, but it's easier to buy a MIDI to CV converter
and connect that instead of the pots (highly liquid or something). The pots are nothing else than
a control voltage (0..5Volt).
Maybe I'll find a way - but I make no promise.
It's more a fun toy than a high end synth (and toys don't have MIDI ;)
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What's the new address for the plans and samples? I had a look in the obvious place but it just said "8 bits are enough"...
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here it is ...
http://www.gjcp.net/~catweazle/PICsynth/
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The pots are nothing else than a control voltage (0..5Volt).
It's more a fun toy than a high end synth (and toys don't have MIDI ;)
I've got a Doepfer that has 4x 0..5V CV outputs so I can try to hook that up, cool.
Toys do have MIDI... I'm currently building Highly Liquid kits for my Speaks, my Atari2600 and my SK1.
I never really thought I wanted MIDI because the bent sound is only the 1st stage, everything ends up as audio in Ableton Live and gets sliced/diced/warped whatever some more.... but I saw a vid of a MIDI 2600 and I was like "wow", I think MIDI control will get me to where I want to be sooner.
Hey how about a trigger input (+5v gate pulse?) so the sequencer advances one step... that would work and it would save you a lot of boring MIDI programming...?
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;D ok, maybe some toys have midi, damn...
good idea trigger for step advance... I'll do that if I got my synth back (lent it a friend)
synching the thing seems to be a important requested feature.
... wishlist is long...
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Trigger for step advance would be awesome man!
Saves you writing all the boring MIDI crap (might not have enough CPU cycles left for that anyway?)
I'll just use the gate of one of my Midi-CV converters, and I guess most folks around here will know how to knock up a trigger signal. :)
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I am having so much problems trying to program the chip. I have a pickit 2. does anyone know of a low cost demo board which could program it, or a cheap programer that works?! thanks x
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Be shure the you connected MCLR, PGC and PGD right. Target (PIC) powered on while programming
I use the GTP-USB+ Programmer
http://www.winpic800.com//index.php?option=com_content&task=blogcategory&id=19&Itemid=88
it's not the cheapest but can program all PICs (including PIC32 and dsPIC), Atmel AVRs and EEPROMs
which is nice if you want to do AVRs and PIC projects.
I don't have a PICkit2, but as I know the "light" version can't program all PICs.
good luck
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If you don't have any possiblities to get it working, I can send you a programmed one.
mail me acidliner<at>web.de
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Hey catweazle, are there any updates on this. I was just looking at the electro music forum and saw some new posts in the Fraktal synth thread there: http://electro-music.com/forum/topic-25422-75.html
I've just finished a new Fraktal synth and its a fantastic machine!
Now all i've got to do is learn some C ;)
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Some people on
http://electro-music.com/forum/post-222876.html (http://electro-music.com/forum/post-222876.html)
had done some nice upgrades like adding a filter, creating Eagle PCB-boards,
... and even a new algorithm is available (Karplus Strong Algorithm emulating plugged strings)
http://www.reprolabs.com/fs7.htm (http://www.reprolabs.com/fs7.htm)
Since I got realtime audiostreaming on the NintendoDS working I've ported the Fraktalsynth Algorithms, including a resonant 12dB Multimode Filter (lowpass,bandpass,highpass), Delay Effect and all with an easy to use interface. * Soon it will be released. *
The NintendoDS is cheap, CPU power, lots of RAM, StorageCard, Touchscreen user interface etc..
so this little guy will be my platform for my next projects ...
... be prepared for some softwarebended noisemakers :D
PS:
learning C is a bit hard in the begining but it's worth the trouble ;D
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(http://www.circuitbenders.co.uk/IMAGES/fraktal/frakmk2-1.jpg)
(http://www.circuitbenders.co.uk/IMAGES/fraktal/frakmk2-2.jpg)
(http://www.circuitbenders.co.uk/IMAGES/fraktal/frakmk2-3.jpg)
mmmm, nice ;D
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Nice work!!!
As promised here is a first review of the Nintendo DS Version ....
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... and here is the DS binary (I use a R4DS Card but should run in No$GBA Emulator)
Rename the file NoiseToys_Alpha.txt into NoiseToys_Alpha.rar (RAR-Archive, since I cannot upload RAR files)
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If anyone still interested in this synth, and if you're not then you should be because is brilliant fun and easy to build, heres an updated hex file that someone else has been working on with 2 extra synth sections and a PCB layout.
http://www.reprolabs.com/fraktal_synth_1.htm (http://www.reprolabs.com/fraktal_synth_1.htm)
Just followthe link at the bottom and keep pressing the 'next' buttons