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1  Using Arduino / Networking, Protocols, and Devices / tlc5940 + high current led driver on: January 09, 2014, 07:41:45 am
i am trying to alter the pwm freq of the tlc output pins.

for my project i need to view the dimming leds through a cellphone camera.
currently i  see (through the cam) the leds flicker or show moving bands.

here is my setup: arduino mini pro -> tlc5940 -> PWM adj pin on high current led driver.

i am testing 2 high current led drivers
based on the ZXLD: https://www.sparkfun.com/products/9748
based on AL8805W5: https://www.sparkfun.com/products/11850
and also have a regular led connected straight to an tlc output.

i am sending dimming values to the arduino via the DMXSerial library:
http://www.mathertel.de/Arduino/DMXSerial.aspx

i read about adjusting TLC_GSCLK_PERIOD and TLC_PWM_PERIOD.
i tried adjusting these values with the following:
TLC_PWM_PERIOD 4096
TLC_GSCLK_PERIOD 1
TLC_PWM_PERIOD 1024
TLC_GSCLK_PERIOD 1
TLC_PWM_PERIOD 512
TLC_GSCLK_PERIOD 1

when using these values the regular led flickers, visible to the eye.
the high current led drivers do not react anymore.
this is most likely due to these led drivers not liking the very high PWM frequencies.

so, my question would be:
A:
how to fine adjust the PWM freq to a point that they are slow enough so the high current led drivers start reacting and fast enough so there is no flicker visible through the camera.

i know this works because i tried feeding a hardware PWM via the analogWrite using a teensy-micro-controller at about 3000 HZ.

B:
when using the fade tlc example the regular leds do not flicker but the high current led drivers do not react.
again this might be due to too high a frequency.
how could i alter the fade frequency?

thanks a lot,
stephan.
2  Products / Arduino Yún / Re: UDP on the Yun on: December 02, 2013, 03:50:42 pm
i am interested in this too and will keep on checking back in the hopes someone get this working.
3  Using Arduino / Networking, Protocols, and Devices / arduino yun and DMXSerial2 or Artnet for RDM on: November 27, 2013, 09:04:52 pm
i am planning a project for which i was hoping to implement wireless RMD/DMX communication.

DMXSerial2 offers RDM bi-directional communication.
http://www.mathertel.de/Arduino/DMXShield.aspx

I am wondering now if this could be coupled with the Yun, or if it would be better to get the regular WIFI shield?

or would it be better to use the artnet node library with the yun wifi:
http://www.deskontrol.net/blog/arduino-based-artnet-node-for-led-pixels/

It would be great to get RDM working since it is bi-directional, not like DMX.

thanks,stephan
4  Using Arduino / Networking, Protocols, and Devices / Re: different serial baud rates for rx and tx on: April 15, 2013, 02:55:06 pm
thanks to all.

i will try switching the baud rates between sending and receiving.

ideally i would figure out how to get my mac to receive at 250k baud.

i read about aliasing baud rates which is done by altering System/Library/Extensions/FTDIUSBSerialDriver.kext
http://www.dbpharrison.com/general/thermitrackdriver/

ftdi has also talks about this in it's manual:
http://www.ftdichip.com/Support/Documen ... Driver.pdf

s.
5  Using Arduino / Networking, Protocols, and Devices / different serial baud rates for rx and tx on: April 10, 2013, 10:47:44 am
hi.

is there a way to have the arduino send data at one baud rate and receive with a different one?

i am using the pins 0 and 1 on an arduino pro mini.
the rx pin receives dmx data at baud 250K
i also want to send out data on the tx pin but at a lower baud rate.

i mainly want to do this, because i can't figure out how to make my max osx computer read serial at 250K baud, since it is not a standard baud rate and not defined in termios.h

thx.
6  Topics / Interactive Art / Re: very long countdown art project on: January 10, 2013, 06:40:16 am
did you ever find a solution to counting up to such a large number?

i looked i to the problem too. specifically only using the eeprom to store the counter.
but the limits are how often you can toggle a bit = 100K times.

i looked in to balanced gray code, which would turn your counter number in to a bit series. this series of bits will use all the bits equally often.

the problem so far is balanced gray code can not be generated with a simple formula, like regular gray code can.

for balanced gray code you need to store a transition sequence that is basically as long as you counter.
in my case that would be 2^21 x 4 bits. so too big to be stored in the progmem.

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