58 lines
1.4 KiB
C
58 lines
1.4 KiB
C
/*
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* Based on microbuilders PWM example.
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*/
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#include "lpc134x.h"
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#include "sysdefs.h"
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#include "core/gpio/gpio.h"
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#include "basic/basic.h"
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uint32_t brightness = 100;
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void backlightInit(void) {
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/* Enable the clock for CT16B1 */
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SCB_SYSAHBCLKCTRL |= (SCB_SYSAHBCLKCTRL_CT16B1);
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/* Configure PIO1.9 as Timer1_16 MAT0 Output */
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IOCON_PIO1_9 &= ~IOCON_PIO1_9_FUNC_MASK;
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IOCON_PIO1_9 |= IOCON_PIO1_9_FUNC_CT16B1_MAT0;
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/* Set default duty cycle (MR1) */
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TMR_TMR16B1MR0 = (0xFFFF * (100 - brightness)) / 100;
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/* External Match Register Settings for PWM */
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TMR_TMR16B1EMR = TMR_TMR16B1EMR_EMC0_TOGGLE | TMR_TMR16B1EMR_EM0;
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/* enable Timer1 */
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TMR_TMR16B1TCR = TMR_TMR16B1TCR_COUNTERENABLE_ENABLED;
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/* Enable PWM0 */
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TMR_TMR16B1PWMC = TMR_TMR16B1PWMC_PWM0_ENABLED;
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// Enable Step-UP
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gpioSetDir(RB_PWR_LCDBL, gpioDirection_Output);
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gpioSetValue(RB_PWR_LCDBL, 0);
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}
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int backlightSetBrightness(uint32_t percentage) {
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if ((percentage < 0) || (percentage > 100)) {
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/* brightness must be a value between 1 and 100 */
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return -1;
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}
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if( percentage == 0 ){
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gpioSetDir(RB_PWR_LCDBL, gpioDirection_Input);
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}else{
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gpioSetDir(RB_PWR_LCDBL, gpioDirection_Output);
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gpioSetValue(RB_PWR_LCDBL, 0);
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}
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/* Set Duty Cycle (MR1) */
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TMR_TMR16B1MR0 = (0xFFFF * (100 - (brightness = percentage))) / 100;
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return 0;
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}
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uint32_t backlightGetBrightness(void) {
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return brightness;
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}
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