View source for STM32F107VC/Using MCBQVGA-TS-Display-v12

=Backlight illumination adjust=
The signal BL_control<ref>[http://www.keil.com/mcbstm32c/mcbstm32c-display-board-schematics.pdf MCBSTM32C Display Schematics] (Loads PDF)</ref> turns on the Backlight LED's controlled by the STLD40D<ref>[http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00098098.pdf STLD40D White LED power supply for large display backlight]</ref> 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). 
#Looking in the [http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/REFERENCE_MANUAL/CD00171190.pdf 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.
#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 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=
*[http://www.keil.com/mcbstm32c/mcbstm32c-display-board-schematics.pdf MCBSTM32C Display Schematics] (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.intelligentdisplay.com/PDFs/SPFD5408B-C3_V04.pdf SPFD5408B 720 channel driver for TFT-LCD Display] (Loads PDF)
*[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)

=References=
<references/>
[[Category:ARM]]