91 lines
3 KiB
C
91 lines
3 KiB
C
/*
|
|
The MIT License (MIT)
|
|
|
|
Copyright (c) 2016 Fred Sundvik
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
of this software and associated documentation files (the "Software"), to deal
|
|
in the Software without restriction, including without limitation the rights
|
|
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
copies of the Software, and to permit persons to whom the Software is
|
|
furnished to do so, subject to the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be included in all
|
|
copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
SOFTWARE.
|
|
*/
|
|
|
|
#include "lcd_backlight.h"
|
|
#include "hal.h"
|
|
|
|
#define RED_PIN 1
|
|
#define GREEN_PIN 2
|
|
#define BLUE_PIN 3
|
|
#define CHANNEL_RED FTM0->CHANNEL[0]
|
|
#define CHANNEL_GREEN FTM0->CHANNEL[1]
|
|
#define CHANNEL_BLUE FTM0->CHANNEL[2]
|
|
|
|
#define RGB_PORT PORTC
|
|
#define RGB_PORT_GPIO GPIOC
|
|
|
|
// Base FTM clock selection (72 MHz system clock)
|
|
// @ 0xFFFF period, 72 MHz / (0xFFFF * 2) = Actual period
|
|
// Higher pre-scalar will use the most power (also look the best)
|
|
// Pre-scalar calculations
|
|
// 0 - 72 MHz -> 549 Hz
|
|
// 1 - 36 MHz -> 275 Hz
|
|
// 2 - 18 MHz -> 137 Hz
|
|
// 3 - 9 MHz -> 69 Hz (Slightly visible flicker)
|
|
// 4 - 4 500 kHz -> 34 Hz (Visible flickering)
|
|
// 5 - 2 250 kHz -> 17 Hz
|
|
// 6 - 1 125 kHz -> 9 Hz
|
|
// 7 - 562 500 Hz -> 4 Hz
|
|
// Using a higher pre-scalar without flicker is possible but FTM0_MOD will need to be reduced
|
|
// Which will reduce the brightness range
|
|
#define PRESCALAR_DEFINE 0
|
|
|
|
void lcd_backlight_hal_init(void) {
|
|
// Setup Backlight
|
|
SIM->SCGC6 |= SIM_SCGC6_FTM0;
|
|
FTM0->CNT = 0; // Reset counter
|
|
|
|
// PWM Period
|
|
// 16-bit maximum
|
|
FTM0->MOD = 0xFFFF;
|
|
|
|
// Set FTM to PWM output - Edge Aligned, Low-true pulses
|
|
#define CNSC_MODE FTM_SC_CPWMS | FTM_SC_PS(4) | FTM_SC_CLKS(0)
|
|
CHANNEL_RED.CnSC = CNSC_MODE;
|
|
CHANNEL_GREEN.CnSC = CNSC_MODE;
|
|
CHANNEL_BLUE.CnSC = CNSC_MODE;
|
|
|
|
// System clock, /w prescalar setting
|
|
FTM0->SC = FTM_SC_CLKS(1) | FTM_SC_PS(PRESCALAR_DEFINE);
|
|
|
|
CHANNEL_RED.CnV = 0;
|
|
CHANNEL_GREEN.CnV = 0;
|
|
CHANNEL_BLUE.CnV = 0;
|
|
|
|
RGB_PORT_GPIO->PDDR |= (1 << RED_PIN);
|
|
RGB_PORT_GPIO->PDDR |= (1 << GREEN_PIN);
|
|
RGB_PORT_GPIO->PDDR |= (1 << BLUE_PIN);
|
|
|
|
#define RGB_MODE PORTx_PCRn_SRE | PORTx_PCRn_DSE | PORTx_PCRn_MUX(4)
|
|
RGB_PORT->PCR[RED_PIN] = RGB_MODE;
|
|
RGB_PORT->PCR[GREEN_PIN] = RGB_MODE;
|
|
RGB_PORT->PCR[BLUE_PIN] = RGB_MODE;
|
|
}
|
|
|
|
void lcd_backlight_hal_color(uint16_t r, uint16_t g, uint16_t b) {
|
|
CHANNEL_RED.CnV = r;
|
|
CHANNEL_GREEN.CnV = g;
|
|
CHANNEL_BLUE.CnV = b;
|
|
}
|
|
|