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Topic: Dimming an LED strip (Read 5 times) previous topic - next topic

arduinohabib

Why don't you first write the code? With the transistor the code would be the same as PWM-ing an LED.
What is man's best friend? The breadboard!

chaser53

The code is already written. Unfortunately I fried my Uno when I was testing a different idea. Do I use a capacitor in conjunction with the transistor to keep a steady,variable voltage going to the led strip? If so, how much (Again, new to circuit building).

arduinohabib

I am sorry you fried your Arduino. You don't need a capacitor; PWM is a pulse, if you add a capacitor it will absobe the pulse and there will be no dimming--full brightness.
What is man's best friend? The breadboard!

CrossRoads

http://www.titanmec.com/doce/product-detail-217.html

Send the correct data to the part - it has PWM control  built in.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

chaser53

alright. Ill have access to a new board tomorrow. Ill see if the PWM and led strip work together. I am thinking that if the power is off for too long, the strip will reset(uses a tm1803 led driver). Im also looking into using a mosfet as a variable resistor.

Crossroads: in reply to your post, the tm1803 has 3 output channels meaning a single ic can control 3 single color leds or 1 RGB led. In my case, its the latter of the two meaning that any change in signal needs to be applied 3 times, once for each color channel. Since Im building an audio visualizer, the brightness changes every loop and since the tm1803 is time based, the calculations to change the color is too slow for the strip to be correctly set to a color sequence (trust me because I did this just before I blew the capacitor on my Uno).

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