help for this circuit number C8051F226DK

Thread Starter

jason1987

Joined Jun 3, 2009
7
hello everyone can someone help mi, using a variable resister to control the LED dimmer.. using silicon software to write a program using ADC and PWM to control the LED dimmer.. anyone can help?
 
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beenthere

Joined Apr 20, 2004
15,819
Please stop doing multiple postings of this question.

"Silicon software" is essentially meaningless. Google finds references, but none that seem to pertain. Can you explain in some detail what it might be?
 

Thread Starter

jason1987

Joined Jun 3, 2009
7
the hardware i was given a variable resister and i hv the circuit diagram.. can help mi take a look at it? at i need to write silicon software to write a C languang.
 

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Arm_n_Legs

Joined Mar 7, 2007
186
You are using the Silicon Lab C8051F226 microcontroller which is a derivatve of the 8051. You are to write the program in C, not using Silicon Lab sofware, but using Keil C compiler. You need to know how to ask the question properly.
 

beenthere

Joined Apr 20, 2004
15,819
That is a manual for the prototyping board. Have you been able to design an interface for the LED dimmer? I would not think that the D to A converter was particularly well suited to doing PWM.

Do you understand the principle of PWM?
 

beenthere

Joined Apr 20, 2004
15,819
It sounds as if you need to do some research before getting started. Pulse width modulation is a means of controlling averave current through a train of pulses with a variable width - http://en.wikipedia.org/wiki/Pulse-width_modulation

As you will see, the ADC (understood as Analog to Digital Converter) may not play a part in doing PWM to control a LED.

However, used with a photosensitive device, the ADC can provide a control input to allow intensity control through a program loop.
 

millwood

Joined Dec 31, 1969
0
As you will see, the ADC (understood as Analog to Digital Converter) may not play a part in doing PWM to control a LED.
you can. you can use a trimmer to generate an analog signal, use the adc to convert the analog signal to get a digital reading of the wiper's position, and use that to control how long you want a port to be set, or cleared. viola! you have your own pwm.

i have a little program that does precisely that.
 

beenthere

Joined Apr 20, 2004
15,819
To jason1987 - Beside trying to ask the same question again, what progress have you made? Do you understand how a PWM signal is generated yet? How about the hardware between the uC and the motor?
 
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