Difference between revisions of "STM32F107VC/Using MCBQVGA-TS-Display-v12"

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#To see Timer 3's possibilities on PB0 look on page 161 section 9.1.11 table 23 it's seen that timer 3 can use a GPIO pin as ''Output Compare Channel X'' when the pin is configured as ''Alternate Function Push-Pull''.
 
#To see Timer 3's possibilities on PB0 look on page 161 section 9.1.11 table 23 it's seen that timer 3 can use a GPIO pin as ''Output Compare Channel X'' when the pin is configured as ''Alternate Function Push-Pull''.
 
#To set PB0 as Alternate Function Push-Pull - See the GPIOx_CRL register on page 166.
 
#To set PB0 as Alternate Function Push-Pull - See the GPIOx_CRL register on page 166.
−
#To configure Timer 3 as continues [[PWM]] output timer see Page 371 section 15.3.9  
+
#To configure Timer 3 as continues [[PWM]] output timer see Page 371 section 15.3.9
 +
===Example code===
 +
Still experimental and missing documentation
 +
;Note:To change Pulse Width change the value of '''TIM3->CCR3'''
 +
<source lang=c>
 +
#include "GPIO_STM32F10x.h"
 +
/*
 +
Example 2:
 +
==========
 +
Using timer 3 to Dim the Backlight in Display
 +
 
 +
Mode : Continues PWM mode to PB0. Section 15.3.9 page 370
 +
    For details see: http://mars.tekkom.dk/mediawiki/index.php/STM32F107VC/Using_MCBQVGA-TS-Display-v12
 +
 
 +
Caveats: Assumes TIMxCLK = 72 MHz (See RCC - Reset And Clock Control)
 +
*/
 +
 
 +
void tim3init( void ) {
 +
GPIOB->CRL |= 0xa;  // Set PB0 as Alternate function Push-Pull
 +
RCC->APB1ENR |= 2; //Enable timer 3 clock (RCC->APB1ENR bit 1 = 1)
 +
 +
   
 +
TIM3->PSC = 72;   // Prescaler: With timer 3 input clock 72 Mhz divide by 72 to 1 Mhz
 +
TIM3->ARR = 1000; // Auto Reload Register set to 1000 divide 1Mhz/1000 = 1 Khz
 +
TIM3->CCR3 = 100; //Compare Register for channel 3
 +
TIM3->CCMR2 |= 7 << 4; //PWM mode 1
 +
TIM3->CCMR2 |= 1 << 3;
 +
TIM3->EGR |= 1; //Update generate
 +
TIM3->CCER |= 1<<8; //Polarity
 +
TIM3->CCER |= 1<<9;
 +
TIM3->CR1 |= 1;
 +
}
 +
 
 +
/* Change Display Backlight Intensity
 +
input: 0 - 17 ( 0 = 0% backlight (All dark) to 17 = 100% backlight (Brigth)
 +
Caveats: No errorcontrol
 +
            When 0 the timer should be turned off and the backlight turned off (PB0=0)
 +
            when 17 the timer should be turned off and the backlight turned on (PB0=1)
 +
*/
 +
void backlight( int intensity ) {
 +
int disvalarr[] = {0,5,10,15,25,35,50,65,80,100,120,150,200,300,400,600,800,1000};
 +
TIM3->CCR3 = disvalarr[intensity];
 +
}
 +
</source>
 +
 
 
=Links=
 
=Links=
 
*[http://www.keil.com/mcbstm32c/mcbstm32c-display-board-schematics.pdf MCBSTM32C Display Schematics] (Loads PDF)
 
*[http://www.keil.com/mcbstm32c/mcbstm32c-display-board-schematics.pdf MCBSTM32C Display Schematics] (Loads PDF)
−
*[http://www.ampdisplay.com/product_specs/2.4-specs/ADI_2.4_AM-240320LDTNQW-T00H.pdf AM-240320LDTNQW TFT-LCD Display module with Touch Panel] (Loads PDF)
+
*[http://gamma.spb.ru/download/AM-240320LDTNQW-T00H.pdf AM-240320LDTNQW TFT-LCD Display module with Touch Panel] (Loads PDF)
 
**[http://www.ampdisplay.com/colortft_specs_18to50.html Display modules]??
 
**[http://www.ampdisplay.com/colortft_specs_18to50.html Display modules]??
 
*[http://www.intelligentdisplay.com/PDFs/SPFD5408B-C3_V04.pdf SPFD5408B 720 channel driver for TFT-LCD Display] (Loads PDF)
 
*[http://www.intelligentdisplay.com/PDFs/SPFD5408B-C3_V04.pdf SPFD5408B 720 channel driver for TFT-LCD Display] (Loads PDF)
−
*[http://www.st.com/internet/analog/product/185203.jsp STMPE811 Touch Screen Controller]
+
*[http://www.st.com/content/ccc/resource/technical/document/datasheet/d3/4a/58/38/4f/fa/46/2d/CD00186725.pdf/files/CD00186725.pdf/jcr:content/translations/en.CD00186725.pdf STMPE811 Touch Screen Controller]
 
*[http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00098098.pdf STLD40D White LED power supply for large display backlight] (Loads PDF)
 
*[http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00098098.pdf STLD40D White LED power supply for large display backlight] (Loads PDF)
 +
 
=References=
 
=References=
 
<references/>
 
<references/>
 
[[Category:ARM]]
 
[[Category:ARM]]

Latest revision as of 09:55, 5 October 2017

Backlight illumination adjust

The signal BL_control[1] turns on the Backlight LED's controlled by the STLD40D[2] IC on the display. To control the illuminace of the LED's its necessary to turn the LED's off and on using Pulse-Width-Modulation (PWM).

Keil MCBSTM32C board

On the Keil MCBSTM32C board the BL_control signal is connected to PB0 (Port B bit 0).

  1. Looking in the Reference Maual on page 173 section 9.3.7 table 44 it's seen that Timer 3 Channel 3 has an alternate function on PB0.
  2. To see Timer 3's possibilities on PB0 look on page 161 section 9.1.11 table 23 it's seen that timer 3 can use a GPIO pin as Output Compare Channel X when the pin is configured as Alternate Function Push-Pull.
  3. To set PB0 as Alternate Function Push-Pull - See the GPIOx_CRL register on page 166.
  4. To configure Timer 3 as continues PWM output timer see Page 371 section 15.3.9

Example code

Still experimental and missing documentation

Note
To change Pulse Width change the value of TIM3->CCR3
#include "GPIO_STM32F10x.h"
/*
Example 2:
==========
Using timer 3 to Dim the Backlight in Display

Mode : Continues PWM mode to PB0. Section 15.3.9 page 370
    For details see: http://mars.tekkom.dk/mediawiki/index.php/STM32F107VC/Using_MCBQVGA-TS-Display-v12

Caveats: Assumes TIMxCLK = 72 MHz (See RCC - Reset And Clock Control)
*/

void tim3init( void ) {
	GPIOB->CRL |= 0xa;  // Set PB0 as Alternate function Push-Pull 
	RCC->APB1ENR |= 2; //Enable timer 3 clock 	(RCC->APB1ENR bit 1 = 1)
		
    
	TIM3->PSC = 72;	  // Prescaler: With timer 3 input clock 72 Mhz divide by 72 to 1 Mhz
	TIM3->ARR = 1000; // Auto Reload Register set to 1000 divide 1Mhz/1000 = 1 Khz
	TIM3->CCR3 = 100; //Compare Register for channel 3
	TIM3->CCMR2 |= 7 << 4; //PWM mode 1
	TIM3->CCMR2 |= 1 << 3;
	TIM3->EGR |= 1; //Update generate
	TIM3->CCER |= 1<<8; //Polarity
	TIM3->CCER |= 1<<9;
	TIM3->CR1 |= 1;
}

/* Change Display Backlight Intensity
 input: 0 - 17 ( 0 = 0% backlight (All dark) to 17 = 100% backlight (Brigth)
 Caveats: No errorcontrol
             When 0 the timer should be turned off and the backlight turned off (PB0=0)
             when 17 the timer should be turned off and the backlight turned on (PB0=1)
*/
void backlight( int intensity ) {
	int disvalarr[] = {0,5,10,15,25,35,50,65,80,100,120,150,200,300,400,600,800,1000};
	TIM3->CCR3 = disvalarr[intensity];
}

Links

References

  1. ↑ MCBSTM32C Display Schematics (Loads PDF)
  2. ↑ STLD40D White LED power supply for large display backlight
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