work in progress

kicad – video tutorial

Kicad is an open source (GPL) software for the creation of electronic schematic diagrams and printed circuit board artwork.

schematic editor & cvpcb (transcript):

pcbnew (transcript):

V-USB kicad project (clean):
http://www.workinprogress.ca/wp-content/uploads/kicad_vusb.zip

Kicad:
http://kicad.sourceforge.net/wiki/index.php/Main_Page

Update:
http://kicad.1301.cz/

Libraries:
http://kicadlib.org/
http://per.launay.free.fr/kicad/kicad_php/composant.php

24

01 2010

by psc
posted in Electronics
5 Comments

filtering pwm for music

i would like to start by saying that this solution might not be the best… if any analog guru read this, please leave a comment.

for 2.75$ you can have a chip that is able to run at 64 mhz (phase-locked loop) and output a pulse width modulation at 250 khz. attiny85 is your friend here. i didn’t found any atmega with this option (pll)… the good news is that it’s fast enough to output a stereo WAV at 16 bits / 48 khz. if you are interested in this project, take a look here: http://elm-chan.org/works/sd8p/report.html

since i want to connect the pwm output in a power amplifier, i need to filter the signal. here’s the waveform of the pulse width modulation @ 440 hz:

now let’s see if we use a simple RC low pass:

looks good to me, but then testing with a triangle instead of an oscillator revealed this:

that’s not beautiful… here’s a close-up:

maybe using more passive filter could help, but since you need to use an op-amp as a buffer (so that your load doesn’t affect the RC filter), why not use a sallen-key topology. this will act as an active low pass filter and a buffer. let’s look at the results:

close-up:

not perfect, but better!

SIMULATIONS
simple RC (250khz = -22db)

sallen-key second-order (250khz = -44db)

sallen-key third-order (250khz = -67db)

third-order is the best and using this method only 1 stage is needed.

when choosing the op-amp, consider this:
100 * highest Q * GBW = Gain Bandwidth Product (read about it here)
slew rate => 2V/µs
i am using a rail-to-rail input / output op-amp.

now simply add an electrolytic capacitor (100 uf) and you can feed an amplifier with the original pwm signal (hopefully).

29

11 2009

by psc
posted in Electronics
No Comments

pure data external pthread template

This external for Pure Data is using POSIX Threads for avoiding glitches in the DSP. Any recommendation to tight it up?

threadtemplate.tar.gz

Bonus:
Le chat sort du sac

Get the Flash Player to see this player.

19

10 2009

by psc
posted in Pure Data
No Comments

V-USB tutorial (software-only usb for mega & tiny)

Arduino use the FTDI chip for usb communication. This chip is expensive and only surface mount. To save money and be able to make a PCB at home, i found a software-only implementation of USB for AVR (attiny, atmega): http://www.obdev.at/products/vusb/index.html.

You don’t need the 2 LEDs.
It’s a visual feedback (debug, bootloader).

I am using an ATMEGA164p.
The example code need to be modify to fit your device (bootloader address, registers, EEPROM functions).

This tutorial is for people who have some experience or are patient. Please pardon my english.

1) breadboard your avr for programmation (SPI / JTAG)

2) download vusb (last version)

BOOTLOADERHID (optional)
3) download bootloadhid (last version)
This bootloader doesn’t require a driver (it’s HID). With it, you will be able to program your firmware without your programmer.

4) delete usbdrv, cp the usbdrv from vusb
5) open usbconfig.h – change the VENDOR and DEVICE name if you want
6) open bootloaderconfig.h – set the pin for usb (USB_CFG_DMINUS_BIT – USB_CFG_DPLUS_BIT) and if you want to be able to reset via usb (USB_CFG_PULLUP_IOPORTNAME). Change the bootloadcondition to suit your needs, i am using the EEPROM to write (from the firmware) and read (from the bootloader) for the condition + 2 leds (so i know that i am in the bootloader).

show code ▼

#define JUMPER_BIT  5
#define BOOTLED_BIT  6
#define BOOTLED_BITB  7

static inline void  bootLoaderInit(void)
{
	DDRD |= (1 << BOOTLED_BIT);     // turn bootloader led on
	DDRD |= (1 << BOOTLED_BITB);     // turn bootloader led on 2
	PORTD |= (1 << JUMPER_BIT);     /* activate pull-up */
	_delay_us(10);  /* wait for levels to stabilize */
}

static inline void  bootLoaderExit(void)
{
    PORTD = (1 << BOOTLED_BIT);                 // turn bootloader led off
    PORTD = (1 << BOOTLED_BITB);                 // turn bootloader led off
}

7) main.c: Edit your condition, mine looks like this:
show code ▼

...
static void leaveBootloader()
{
 DBG1(0x01, 0, 0);
 bootLoaderExit();
 cli();
...

// - Write to EEPROM
void eepromWrite(unsigned int uiAddress, unsigned char ucData)
{
 /* Wait for completion of previous write */
 while(EECR & (1<<EEPE));
 /* Set up address and Data Registers */
 EEAR = uiAddress;
 EEDR = ucData;
 cli();
 /* Write logical one to EEMPE */
 EECR |= (1<<EEMPE);
 /* Start eeprom write by setting EEPE */
 EECR |= (1<<EEPE);
 sei();
}

// - Read EEPROM
unsigned char eepromRead(unsigned int uiAddress)
{
 /* Wait for completion of previous write */
 while(EECR & (1<<EEPE));
 /* Set up address register */
 EEAR = uiAddress;
 /* Start eeprom read by writing EERE */
 EECR |= (1<<EERE);
 /* Return data from Data Register */
 return EEDR;
}

int main(void)
{
 /* initialize hardware */
 bootLoaderInit();
 odDebugInit();
 DBG1(0x00, 0, 0);

 unsigned char do_boot_load;
 unsigned char do_boot_load_via_eeprom;

 do_boot_load = ~PIND & (1 << JUMPER_BIT);  // see if jumper is set (= 0)
 do_boot_load_via_eeprom = eepromRead(0); // bootloader bit in eeprom address 0

 /* jump to application if jumper is set */
 if(do_boot_load || do_boot_load_via_eeprom){
 eepromWrite(0, 0); // reset bit in eeprom
 PORTD &= ~(1 << BOOTLED_BIT);  /// Light led
 PORTD &= ~(1 << BOOTLED_BITB);  /// Light second led

 uchar i = 0, j = 0;
#ifndef TEST_MODE
 GICR = (1 << IVCE);  /* enable change of interrupt vectors */
 GICR = (1 << IVSEL); /* move interrupts to boot flash section */
#endif
 initForUsbConnectivity();
 do{ /* main event loop */
 wdt_reset();
 usbPoll();
#if BOOTLOADER_CAN_EXIT
 if(exitMainloop){
#if F_CPU == 12800000
 break;  /* memory is tight at 12.8 MHz, save exit delay below */
#endif
 if(--i == 0){
 if(--j == 0)
 break;
 }
 }
#endif
 }while(1);
 }
 leaveBootloader();
 return 0;
}

8) edit the Makefile

You need to know the BOOTLOADER_ADDRESS of your device (learn more about bootloader). Basically your datasheet will tell you the Start Bootloader section (look for Boot Size Configuration) in word address. You need to multiply it by 2 (the toolchain works on BYTE ADDRESS). For example, the atmega164p for 1024 words, the address is: 1C00 * 2 = 3800.

I am using a 20mhz clock, V-USB can be clocked with 12 Mhz, 15 MHz, 16 MHz or 20 MHz crystal or from a 12.8 MHz or 16.5 MHz internal RC oscillator.

Finally, you need to set the fuse correctly:

Boot Flash section size = 1024 words
Uncheck Divide clock by 8 internally

DEVICE = atmega164p
BOOTLOADER_ADDRESS = 3800
F_CPU = 20000000
FUSEH = 0xd8
FUSEL = 0xff
PROGRAMMER = avrispmkII
PORT = usb
...

make fuse
make flash

Now that you have the bootloaderhid, let’s write a simple firmware to test it.

test.c

#define F_CPU 20000000

#include <avr/io.h>
#include <util/delay.h>

int main(void) {

	// Set Port B pins as all outputs
	DDRB = 0xff;

  while(1) {

    PORTB = 0xFF;
    _delay_ms(100);

    PORTB = 0x00;
    _delay_ms(200);

  }

  return 1;
}

then:
avr-gcc -mmcu=atmega164p -Os test.c
avr-objcopy -j .text -j .data -O ihex a.out a.hex

cd bootloader/commandline
edit main.c if you changed the VENDOR and PRODUCT string
make

You need to connect the usb cable while holding the reset button. 2 LEDs should light up and you should see in dmesg something like:

[ 1727.956432] usb 3-2: new low speed USB device using uhci_hcd
[ 1728.119279] usb 3-2: configuration #1 chosen from 1 choice
[ 1728.142142] generic-usb 0003:16C0:05DF.000A: hiddev97,hidraw4: USB HID v1.01 Device [YOURVENDOR YOURPRODUCT] on usb-0000:00:1a.0-2/input0

Do:
./bootloadHID -r a.hex

FIRMWARE

Now what you want in your custom firmware is a way to tell your device to go in the bootloader (so you don’t have to hold the reset button anymore). With this method in place, adding the reset button is optional, but recommanded (in case you break something in the firmware, you need a way to go back in the bootloader).

Remember, in the bootloader we are reading the EEPROM to see if we need to stay in the bootloader section, if not we load the firmware. So in the firmware we will write the EEPROM if we want to go in the bootloader.
show code ▼

// - Write to EEPROM
void eepromWrite(unsigned int uiAddress, unsigned char ucData) {
  while(EECR & (1<<EEPE));
  EEAR = uiAddress;
  EEDR = ucData;
  cli();
  EECR |= (1<<EEMPE);
  EECR |= (1<<EEPE);
  sei();
}

/* BOOTLOADER  */
void (*jump_to_bootloader)(void) = 0x1C00; __attribute__ ((unused))

void startBootloader(void) {

		eepromWrite(0 , 1);				// stay in bootloader

		TIMSK0 &= ~(1<<TOIE0);			// disable timer overflow

		cli();							// turn off interrupts
		wdt_disable();					// disable watchdog timer
		usbDeviceDisconnect(); 			// disconnect from USB bus

		cbi(ADCSRA, ADIE);				// disable ADC interrupts
		cbi(ADCSRA, ADEN);				// disable ADC (turn off ADC power)

		PORTA = 0;						// pull all pins low
		PORTB = 0;
		PORTC = 0;						

		jump_to_bootloader();
}

// - main
int main(void)
{

	while(1) {

		//jump to bootloader if jumper is HIGH
		if(bit_is_clear(PIND, 5)) {
			startBootloader();
		}
	}
	return 0;
}

You are ready to write the firmware for your application. Since you are using V-USB not only it let you upgrade your firmware very easily, but you can of course send and receive message between your computer and the device. Here’s an example of sending the value of a potentiometer to your computer and telling your device to blink a led at a certain speed. This example is for my device, Atmega164p.

vusbtut.tar.gz

WINDOWS
You can trick Windows so it doesn’t popup the driver installation when you plug your device. Your need to use a HID descriptor (Vendor type requests sent to custom HID class device).

hiddescriptor.h
show code ▼

// This HidReportDescriptor is not used, it's only here for avoiding a driver popup install on Windows
// See: Vendor type requests sent to custom HID class device
// http://vusb.wikidot.com/usb-device-classes

PROGMEM char usbHidReportDescriptor[33] = {
0x06, 0x00, 0xff,              // USAGE_PAGE (Generic Desktop)
0x09, 0x01,                    // USAGE (Vendor Usage 1)
0xa1, 0x01,                    // COLLECTION (Application)
0x15, 0x00,                    //   LOGICAL_MINIMUM (0)
0x26, 0xff, 0x00,              //   LOGICAL_MAXIMUM (255)
0x75, 0x08,                    //   REPORT_SIZE (8)

0x85, 0x01,                    //   REPORT_ID (1)
0x95, 0x06,                    //   REPORT_COUNT (6)
0x09, 0x00,                    //   USAGE (Undefined)
0xb2, 0x02, 0x01,              //   FEATURE (Data,Var,Abs,Buf)

0x85, 0x02,                    //   REPORT_ID (2)
0x95, 0x83,                    //   REPORT_COUNT (131)
0x09, 0x00,                    //   USAGE (Undefined)
0xb2, 0x02, 0x01,              //   FEATURE (Data,Var,Abs,Buf)
0xc0                           // END_COLLECTION
};

usbconfig.h
show code ▼

#define USB_CFG_DEVICE_CLASS        0    /* set to 0 if deferred to interface */
#define USB_CFG_DEVICE_SUBCLASS     0
/* See USB specification if you want to conform to an existing device class.
* Class 0xff is "vendor specific".
*/
#define USB_CFG_INTERFACE_CLASS     0x03   /* define class here if not at device level */
#define USB_CFG_INTERFACE_SUBCLASS  0
#define USB_CFG_INTERFACE_PROTOCOL  0
/* See USB specification if you want to conform to an existing device class or
* protocol. The following classes must be set at interface level:
* HID class is 3, no subclass and protocol required (but may be useful!)
* CDC class is 2, use subclass 2 and protocol 1 for ACM
*/
#define USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH    33

main.c

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <avr/wdt.h>
#include "usbdrv.h"
#include "hiddescriptor.h"

Here’s an example for installing the software & driver:
edubeat.zip

HOST SOFTWARE

Here’s the most basic host software written in python.
show code ▼

import usb

def findDevice(vendor_id):
	buses = usb.busses()
	for bus in buses :
		for device in bus.devices :
			print 'idVendor: %x' % device.idVendor
			if device.idVendor == vendor_id:
				print 'Found'
				return device
	return None

class VUSB:
	USB_VENDOR_ID = 0x16C0
	REQUEST_TYPE = usb.TYPE_VENDOR | usb.RECIP_DEVICE | usb.ENDPOINT_IN

	USB_BUFFER_SIZE = 2
	CMD_ZERO = 0

	def __init__(self):
		device = findDevice(self.USB_VENDOR_ID)
		if not device:
			raise Exception('Device not available')
		self.handle = device.open()

	def getBufferSize(self):
		return self.send_cmd(self.CMD_ZERO)

	def send_cmd(self, cmd, param=0):
		val = self.handle.controlMsg(requestType = self.REQUEST_TYPE, request = cmd, value = param, buffer = self.USB_BUFFER_SIZE)
		return val

def main():
	client = VUSB()
	print client.getBufferSize()

if __name__ == '__main__':
	main()

HARDWARE

V-USB runs on any AVR microcontroller with at least 2 kB of Flash memory, 128 bytes RAM and a clock rate of at least 12 MHz. For example the ATTINY25 can do the job. The price of this chip is 1.66 USD!

TEMPLATE

Here’s my template for the Atmega164p. This firmware is ready for ADC free-running mode, SPI master (you need to +5V PB4), external interrupts (PORTC), EEPROM read / write, jump to bootloader.
show code ▼

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <avr/wdt.h>
#include <util/delay.h>

#include "usbdrv.h"
#include "hiddescriptor.h"
#include "utils.h"

// - Define
#define DD_MOSI     PINB5
#define DD_SCK      PINB7
#define ADC_PINS 8

// - Global
static uint8_t usb_reply[10];

// - Write to EEPROM
void eepromWrite(unsigned int uiAddress, unsigned char ucData) {
while(EECR & (1<<EEPE));
EEAR = uiAddress;
EEDR = ucData;
cli();
EECR |= (1<<EEMPE);
EECR |= (1<<EEPE);
sei();
}

// - Read EEPROM
unsigned char eepromRead(unsigned int uiAddress) {
while(EECR & (1<<EEPE));
EEAR = uiAddress;
EECR |= (1<<EERE);
return EEDR;
}

// - Bootloader
void (*jump_to_bootloader)(void) = 0x1C00; __attribute__ ((unused))

void startBootloader(void) {
eepromWrite(0 , 1);                // stay in bootloader
TIMSK0 &= ~(1<<TOIE0);            // disable timer overflow
cli();                            // turn off interrupts
wdt_disable();                    // disable watchdog timer
usbDeviceDisconnect();             // disconnect from USB bus
cbi(ADCSRA, ADIE);                // disable ADC interrupts
cbi(ADCSRA, ADEN);                // disable ADC (turn off ADC power)
jump_to_bootloader();
}

// - usbFunctionSetup
USB_PUBLIC uchar usbFunctionSetup(uchar data[8])
{
usbRequest_t    *rq = (void *)data;
static uchar    replyBuf[10];

usbMsgPtr = replyBuf;
if(rq->bRequest == 0) { //POST

replyBuf[0] = usb_reply[0];
replyBuf[1] = usb_reply[1];
replyBuf[2] = usb_reply[2];
replyBuf[3] = usb_reply[3];
replyBuf[4] = usb_reply[4];
replyBuf[5] = usb_reply[5];
replyBuf[6] = usb_reply[6];
replyBuf[7] = usb_reply[7];
replyBuf[8] = usb_reply[8];
replyBuf[9] = usb_reply[9];
return 10;

} else if(rq->bRequest == 1) { //GET
//rq->wIndex.bytes[0];
//rq->wValue.bytes[0];
}
return 0;
}

// - InterruptInit
void InterruptInit() {
PCICR |= (1 << PCIE2);
PCMSK2 |= (1 << PCINT23) | (1 << PCINT22) | (1 << PCINT21) | (1 << PCINT20) | (1 << PCINT19) | (1 << PCINT18) | (1 << PCINT17) | (1 << PCINT16);
}

// - InterruptTrigged
SIGNAL (SIG_PIN_CHANGE2)
{
//CODE
}

// - SPI_MasterInit
void SPI_MasterInit(void)
{
/* Set MOSI and SCK output, all others input */
DDRB = (1<<DD_MOSI)|(1<<DD_SCK);

/* Enable SPI, Master, set clock rate fck/16 */
SPCR = (1<<SPE)|(1<<MSTR);
SPSR = (1<<SPI2X);
}

// - SPI_MasterTransmit
void SPI_MasterTransmit(char cData)
{
/* Start transmission */
SPDR = cData;
/* Wait for transmission complete */
while(!(SPSR & (1<<SPIF)))
;
}

// - ADC_setPint
void ADC_setPin (int8_t pin) {
pin %= ADC_PINS;
pin   |= ADMUX & -8;
ADMUX  = pin;
}

// - hardwareInit
static void hardwareInit(void)
{
//USB

uchar i, j;

/* activate pull-ups except on USB lines */
USB_CFG_IOPORT = (uchar) ~ ((1 << USB_CFG_DMINUS_BIT) | (1 << USB_CFG_DPLUS_BIT));

/* all pins input except USB (-> USB reset) */
#ifdef USB_CFG_PULLUP_IOPORT    /* use usbDeviceConnect()/usbDeviceDisconnect() if available */
USBDDR = 0;        /* we do RESET by deactivating pullup */
usbDeviceDisconnect();
#else
USBDDR = (1 << USB_CFG_DMINUS_BIT) | (1 << USB_CFG_DPLUS_BIT);
#endif

j = 0;
while (--j) {        /* USB Reset by device only required on Watchdog Reset */
i = 0;
while (--i);    /* delay >10ms for USB reset */
}

#ifdef USB_CFG_PULLUP_IOPORT
usbDeviceConnect();
#else
USBDDR = 0;        /*  remove USB reset condition */
#endif

// ADC SETUP :: FREE RUNNING MODE

// PRESCALER 64
ADCSRA |= (1 << ADPS2) | (1 << ADPS1) | (0 << ADPS0);
// AUTO TRIGGER ENABLE
ADCSRA |= (1 << ADATE);
// AVCC with external capacitor at AREF pin
ADMUX |= (0 << REFS1) | (1 << REFS0);
// RIGHT ADJUST
ADMUX |= (0 << ADLAR);
// CHANNEL 0
ADMUX |= (0 << MUX4) | (0 << MUX3) | (0 << MUX2) | (0 << MUX1) | (0 << MUX0);
// FREE RUNNING MODE
ADCSRB |= (0 << ADTS2) | (0 << ADTS1) | (0 << ADTS0);
// ENABLE ADC
ADCSRA |= (1 << ADEN);

// PORT A: INPUT
DDRA = 0x00;
PORTA = 0x00;

// PORT B: OUTPUT
DDRB = 0xFF;

// PORT C: INPUT
DDRC = 0x00;

//POWER LED
DDRD |= (1 << 6);
PORTD &= ~(1 << 6);

//SPI init
SPI_MasterInit();

//Interrupt init
InterruptInit();
}

// - Main
int main(void)
{
wdt_enable(WDTO_1S);
hardwareInit();
usbInit();
sei();

ADCSRA |= (1 << ADSC); //Start Free Running Mode

while(1) {
wdt_reset();
usbPoll();

//BOOTLOADER
if(bit_is_clear(PIND, 5)) {
startBootloader();
}

//SPI CODE
SPI_MasterTransmit('A');

//YOUR CODE

//USB TEST
usb_reply[0] = 1;
usb_reply[1] = 2;
usb_reply[2] = 3;
usb_reply[3] = 4;
usb_reply[4] = 5;
usb_reply[5] = 6;
usb_reply[6] = 7;
usb_reply[7] = 8;
usb_reply[8] = 0;
usb_reply[9] = 0;

}
return 0;
}

MORE INFORMATION

You can find more information about the API / USB Device Class / Host Software on the wiki of V-USB.

30

08 2009

by psc
posted in Electronics
3 Comments

speech recognition & arduino

Speech recognition done with Simon

26

08 2009

by psc
posted in Electronics
No Comments

4 bits / 4 channels

Based on:
http://code.google.com/p/4bitsynth/

Atmega48 / pwm: square, triangle, noise.

Aphex Twin in 4 bits / 4 channels:

25

08 2009

by psc
posted in Electronics
No Comments

face 2 blender

21

07 2009

by psc
posted in Blender, Pure Data
No Comments

gesture recognition in pure data with easystroke

14

07 2009

by psc
posted in Pure Data
2 Comments

sphinx3 to pure data

1- Basic software installation
sudo apt-get install build-essential autoconf libtool automake libasound2-dev python-dev subversion sox libsox-fmt-all

2- Getting and installing Sphinx3

Download:
sphinx3
sphinxbase

mkdir sphinx && cd sphinx
tar xzpf sphinx3...
tar xzpf sphinxbase...
cd sphinxbase
./autogen.sh --prefix=/usr/local
make && make install
cd sphinx3
./autogen.sh --prefix=/usr/local
make && make install
ldconfig
cd python
nano setup.py (MODIFY THE PATHS)
python setup.py install

3- Download the patch, python script and lexical

wget http://puredata.info/Members/patrick/sphinx2pd
tar xzpf sphinx2pd.tar.gz
cd sphinx2pd
pd sphinx2pd.pd

Make your own lexical and language modeling files (optional)
Upload your textfile containing your puredata commands here:
http://www.speech.cs.cmu.edu/tools/lmtool.html

Download the gzip’d tar file & unzip it to /dic
Dump in binary:

svn co https://cmusphinx.svn.sourceforge.net/svnroot/cmusphinx/trunk/share/lm3g2dmp
cd lm3g2dmp && make && cd ..
lm3g2dmp/lm3g2dmp dic/XXXX.sent.arpabo dic
mv dic/XXXX.sent.arpabo.DMP dic/pd.dmp
mv dic/XXXX.dic dic/pd.dic

07

07 2009

by psc
posted in Pure Data
No Comments

electret microphone amplifier

What is the difference between MIC and LINE level?
Level refers to the relative strength of the signal and is measured in decibels. LINE level sources are much-amplified signals over MIC (microphone) level signals. Line level is usually between -10 to +4 dbm in strength while MIC levels are normally -60 dbm.

Line OUT signal voltage and impedance levels?
The line output “standard” designed to drive a load of 600 ohms or greater, at a mean signal level of 0.775V RMS. An exception exists in respect of compact disc players, where the output level is most commonly 2V RMS.

Preamplifier schematic
Thanks to Andy Collinson for sharing his circuit design.

How does it sound?
Electret microphone
Sensitivity: -35 to +4dB
Signal to noise ratio: 62dB
Recorded at 96000 hertz @ 24 bits

emc_kalimba.wav (right click and save)

Comparing this Electret microphone (6$ USD) with a r-f-t funkwerk m16 mk (1700$ USD tube microphone):

electret.wav (right click and save)
m16mk.wav (right click and save)

03

07 2009

by psc
posted in Electronics
No Comments

work in progress

kicad – video tutorial

24

01 2010

filtering pwm for music

29

11 2009

pure data external pthread template

19

10 2009

V-USB tutorial (software-only usb for mega & tiny)

30

08 2009

speech recognition & arduino

26

08 2009

4 bits / 4 channels

25

08 2009

face 2 blender

21

07 2009

gesture recognition in pure data with easystroke

14

07 2009

sphinx3 to pure data

07

07 2009

electret microphone amplifier

03

07 2009

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