# Help with controlling RGB LED strip with potentiometers

Thread Starter

#### Torran Dodd

Joined Nov 22, 2017
15
So I am doing a school project, and decided to make a controller for an RGB LED strip.

I was planning just a simple box, with 12v DC coming in and 4 potentiometers on the front.
Each potentiometer is wired up to a single channel on the LED strip:
- one to the 12v channel (to control brightness)
- one to each of the colour channels to control them

I was wondering if this would work, and if so, which type of potentiometer I would use as I have looked into them and and a bit overwhelmed with all the different types xD

Any feedback would be greatly appreciated

#### Sensacell

Joined Jun 19, 2012
2,568
While it's theoretically possible to use a potentiometer to do this, it's not the best idea.

You would need a high power potentiometer (rheostat) that will be large, rare and expensive.
The range of dimming will also be non-linear and generally disappointing.

Pulse Width Modulation (PWM) is the way to go.

#### DickCappels

Joined Aug 21, 2008
6,454
Can you point to a simple PWM dimmer that would be easy to make and use?

#### Picbuster

Joined Dec 2, 2013
1,008
I don't know what your educational level is.
However; use a pic16f690 and a lm7805, few cap's resistors, pots and fets to drive the leds.
But you need to write a simple program to read the pots and translate to PWM.
It will be a nice exercise and you will learn a lot about PWM leds( relation current and light), micro controllers, calculating resistors.
Go for C programming it's free from Microchip plus demo programs and ready made boards doing what you want ( fets to furnish)
It's also cheap the pic 2$the pots are the most expensive parts 2-3$ each.
yes, you can do this with 555 but your at school to learn electronics not to play with one component.

Send a request when you get stuck we will help you.

Good luck
Picbuster

Thread Starter

#### Torran Dodd

Joined Nov 22, 2017
15
While it's theoretically possible to use a potentiometer to do this, it's not the best idea.

You would need a high power potentiometer (rheostat) that will be large, rare and expensive.
The range of dimming will also be non-linear and generally disappointing.

Pulse Width Modulation (PWM) is the way to go.
I don't know what your educational level is.
However; use a pic16f690 and a lm7805, few cap's resistors, pots and fets to drive the leds.
But you need to write a simple program to read the pots and translate to PWM.
It will be a nice exercise and you will learn a lot about PWM leds( relation current and light), micro controllers, calculating resistors.
Go for C programming it's free from Microchip plus demo programs and ready made boards doing what you want ( fets to furnish)
It's also cheap the pic 2$the pots are the most expensive parts 2-3$ each.
yes, you can do this with 555 but your at school to learn electronics not to play with one component.

Send a request when you get stuck we will help you.

Good luck
Picbuster
What about something like this:
WINGONEER DC Motor Speed Control Driver Board 3V-35V 5A PWM Controller Stepless DC 3V 6V 12V 24V 35V Variable Voltage Regulator Dimmer Governor Switching Build with LED Indicator and Switch Function

Would that work instead of potentiometers?

Last edited by a moderator:

#### dl324

Joined Mar 30, 2015
10,933
So I am doing a school project, and decided to make a controller for an RGB LED strip.
What is the objective of your project?

#### philba

Joined Aug 17, 2017
960
That might work but since you have not said what current draw your strips have, it's hard to answer your question. In addition, just a headline description (probably the title of an ebay ad) isn't really enough - link to the actual page is better.

#### Picbuster

Joined Dec 2, 2013
1,008
What about something like this:
WINGONEER DC Motor Speed Control Driver Board 3V-35V 5A PWM Controller Stepless DC 3V 6V 12V 24V 35V Variable Voltage Regulator Dimmer Governor Switching Build with LED Indicator and Switch Function

Would that work instead of potentiometers?
I don't know why you shouting but Torran is a student an we should give him a challenge to achieve something not to solve his technical problems.
Train a person to use his grey mass enabling him to learn from fails and end up as a good designer.

Picbuster

Last edited by a moderator:
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