PWM Motor Controller Interface - Revision history

Preet: /* PWM for LPC17xx */

2013-11-06T17:03:43Z

‎PWM for LPC17xx

Preet: /* PWM for LPC17xx */

2012-11-22T16:36:41Z

‎PWM for LPC17xx

Preet: /* PWM for LPC17xx */

2012-11-22T16:07:53Z

‎PWM for LPC17xx

Preet: /* PWM for LPC17xx */

2012-11-22T02:18:13Z

‎PWM for LPC17xx

Preet: /* PWM for LPC17xx */

2012-11-22T02:15:57Z

‎PWM for LPC17xx

Preet: /* Application */

2012-11-20T22:28:49Z

‎Application

Preet: /* Application */

2012-11-20T19:58:20Z

‎Application

Preet: /* Application */

2012-11-20T19:57:42Z

‎Application

Preet: Created page with "== What is PWM == PWM stands for '''P'''ulse '''W'''idth '''M'''odulation. A signal duty cycle is controlled to produce the pulse width. == Application == The application ..."

2012-11-20T19:55:09Z

Created page with "== What is PWM == PWM stands for '''P'''ulse '''W'''idth '''M'''odulation. A signal duty cycle is controlled to produce the pulse width. == Application == The application ..."

New page

== What is PWM ==
PWM stands for '''P'''ulse '''W'''idth '''M'''odulation. A signal duty cycle is controlled to produce the pulse width.

== Application ==
The application of a PWM is usually in motor controls. If a motor is attached to your PWM signal, you could control the motor's speed using the PWM. Imagine that the PWM you produce lasts for one second (1 Hz). Now, imagine that the PWM is high 10% of the time and LOW 90% of the time. What you will end up doing is turning on the motor only 1/10th of a second, hence controlling the motor speed.
<syntaxhighlight>
/*
Example PWM that is ~ 25% HIGH, 75% LOW
__ __ __
| | | | | |
___| |________| |________| |_________

Example PWM that is ~ 90% HIGH, 10% LOW
_________ _________ _________
| | | | |
___| |_| |_|
*/
</syntaxhighlight>

<BR/>
Now imagine that this 1Hz signal is changed to 10KHz. Now, you will no longer hear the motor turn on just for 1/10th of a second. Now, the motor will produce a high frequency noise depending on the pulse frequency. The turning ON and OFF will happen at a very high rate producing a very smooth operation of the motor that you can control digitally.

== PWM for LPC17xx ==
TO DO

== Motor Wiring Example ==
TO DO

@@ Line 20: / Line 20: @@
 == PWM for LPC17xx ==
 Steps to use a pin for a PWM :
 *  Locate a "PWM" pin on your board.
-*:   On SJ-One Board, you should see PWM1-2, PWM1-4, and PWM1-5.
+*:   On SJ-One Board, you should see PWM1-2, PWM1-4, and PWM1-5 etc. on PORT2
 *:   PWM1-2 is '''PWM2''', PWM1-4 is '''PWM4''', and PWM1-5 is '''PWM5'''
 *  Use the sample code below.

@@ Line 29: / Line 29: @@
 <BR/>
 <syntaxhighlight>
 int main(void)
+{

@@ Line 24: / Line 24: @@
 *  Locate a "PWM" pin on your board.
 *:   On SJ-One Board, you should see PWM1-2, PWM1-4, and PWM1-5.
-*:   PWM1-2 is PWM2, PWM1-4 is PWM4, and PWM1-5 is PWM5
+*:   PWM1-2 is '''PWM2''', PWM1-4 is '''PWM4''', and PWM1-5 is '''PWM5'''
 *  Use the sample code below.

@@ Line 20: / Line 20: @@
 == PWM for LPC17xx ==
 Steps to use a pin for a PWM :
-*  Please grab the PWM from my [https://sourceforge.net/projects/cmpe146freertos/files/lpc_pwm.hpp/download SourceForge] repository.
+*  Please grab the PWM code from my [https://sourceforge.net/projects/cmpe146freertos/files SourceForge] repository.
 *  Locate a "PWM" pin on your board.
 *:   On SJ-One Board, you should see PWM1-2, PWM1-4, and PWM1-5.

← Older revision		Revision as of 22:28, 20 November 2012
Line 16:		Line 16:


−	Now imagine that this 1Hz signal is changed to ~~10KHz~~. ~~Now, you~~ will no longer hear the motor turn on just for 1/10th of a second. ~~Now, the~~ motor will produce a high frequency noise ~~depending~~ on ~~the pulse frequency. The turning ON~~ and ~~OFF will happen~~ at a very ~~high~~ rate ~~producing a~~ very smooth operation of the motor ~~that~~ you can control digitally.	+	Now imagine that this 1Hz signal is changed to 1000 Hz. You will no longer hear the motor turn on just for 1/10th of a second. The motor will instead produce a high frequency noise as it is being switched on and off at a very fast rate. This will yield very smooth operation of the motor and hence you can control digitally.

	== PWM for LPC17xx ==		== PWM for LPC17xx ==

← Older revision		Revision as of 19:58, 20 November 2012
Line 16:		Line 16:


−	~~<BR/>~~
	Now imagine that this 1Hz signal is changed to 10KHz. Now, you will no longer hear the motor turn on just for 1/10th of a second. Now, the motor will produce a high frequency noise depending on the pulse frequency. The turning ON and OFF will happen at a very high rate producing a very smooth operation of the motor that you can control digitally.		Now imagine that this 1Hz signal is changed to 10KHz. Now, you will no longer hear the motor turn on just for 1/10th of a second. Now, the motor will produce a high frequency noise depending on the pulse frequency. The turning ON and OFF will happen at a very high rate producing a very smooth operation of the motor that you can control digitally.

@@ Line 4: / Line 4: @@
 == Application ==
 The application of a PWM is usually in motor controls.  If a motor is attached to your PWM signal, you could control the motor's speed using the PWM.  Imagine that the PWM you produce lasts for one second (1 Hz).  Now, imagine that the PWM is high 10% of the time and LOW 90% of the time.  What you will end up doing is turning on the motor only 1/10th of a second, hence controlling the motor speed.
-<syntaxhighlight>
-/*
+    Example PWM that is ~ 25% HIGH, 75% LOW
-Example PWM that is ~ 25% HIGH, 75% LOW
+        __          __          __
-    __          __          __
+       |  |        |  |        |  |
-   |  |        |  |        |  |
+    ___|  |________|  |________|  |_________
 ___|  |________|  |________|  |_________
 <BR/>