2 * Backlighting code for PS2AVRGB boards (ATMEGA32A)
3 * Kenneth A. (github.com/krusli | krusli.me)
9 #include <avr/pgmspace.h>
10 #include <avr/interrupt.h>
12 #include "backlight_custom.h"
13 #include "breathing_custom.h"
19 // Port D: digital pins of the AVR chipset
20 #define NUMLOCK_PORT (1 << 1) // 1st pin of Port D (digital)
21 #define CAPSLOCK_PORT (1 << 2) // 2nd pin
22 #define BACKLIGHT_PORT (1 << 4) // 4th pin
23 #define SCROLLLOCK_PORT (1 << 6) // 6th pin
25 #define TIMER_CLK_DIV64 0x03 ///< Timer clocked at F_CPU/64
26 #define TIMER1PRESCALE TIMER_CLK_DIV64 ///< timer 1 prescaler default
28 #define TIMER_PRESCALE_MASK 0x07 ///< Timer Prescaler Bit-Mask
31 #define TIMER_TOP 255 // 8 bit PWM
33 extern backlight_config_t backlight_config;
37 * Port Registers: https://www.arduino.cc/en/Reference/PortManipulation
38 * TCCR1A: https://electronics.stackexchange.com/questions/92350/what-is-the-difference-between-tccr1a-and-tccr1b
39 * Timers: http://www.avrbeginners.net/architecture/timers/timers.html
40 * 16-bit timer setup: http://sculland.com/ATmega168/Interrupts-And-Timers/16-Bit-Timer-Setup/
41 * PS2AVRGB firmware: https://github.com/showjean/ps2avrU/tree/master/firmware
45 // turn LEDs on and off depending on USB caps/num/scroll lock states.
46 void led_set_user(uint8_t usb_led) {
47 if (usb_led & (1 << USB_LED_NUM_LOCK)) {
50 PORTD |= NUMLOCK_PORT;
53 DDRD &= ~NUMLOCK_PORT;
54 PORTD &= ~NUMLOCK_PORT;
57 if (usb_led & (1 << USB_LED_CAPS_LOCK)) {
58 DDRD |= CAPSLOCK_PORT;
59 PORTD |= CAPSLOCK_PORT;
61 DDRD &= ~CAPSLOCK_PORT;
62 PORTD &= ~CAPSLOCK_PORT;
65 if (usb_led & (1 << USB_LED_SCROLL_LOCK)) {
66 DDRD |= SCROLLLOCK_PORT;
67 PORTD |= SCROLLLOCK_PORT;
69 DDRD &= ~SCROLLLOCK_PORT;
70 PORTD &= ~SCROLLLOCK_PORT;
74 #ifdef BACKLIGHT_ENABLE
76 // sets up Timer 1 for 8-bit PWM
77 void timer1PWMSetup(void) { // NOTE ONLY CALL THIS ONCE
79 TCCR1A &= ~(1 << 1); // cbi(TCCR1A,PWM11); <- set PWM11 bit to HIGH
80 TCCR1A |= (1 << 0); // sbi(TCCR1A,PWM10); <- set PWM10 bit to LOW
82 // clear output compare value A
86 // clear output comparator registers for B
87 OCR1BH = 0; // outb(OCR1BH, 0);
88 OCR1BL = 0; // outb(OCR1BL, 0);
92 void timer1Init(void) {
93 // timer1SetPrescaler(TIMER1PRESCALE)
95 (TCCR1B) = ((TCCR1B) & ~TIMER_PRESCALE_MASK) | TIMER1PRESCALE;
98 TCNT1H = 0; // outb(TCNT1H, 0);
99 TCNT1L = 0; // outb(TCNT1L, 0);
101 // TOIE1: Timer Overflow Interrupt Enable (Timer 1);
102 TIMSK |= _BV(TOIE1); // sbi(TIMSK, TOIE1);
107 void timer1UnInit(void) {
108 // set prescaler back to NONE
109 (TCCR1B) = ((TCCR1B) & ~TIMER_PRESCALE_MASK) | 0x00; // TIMERRTC_CLK_STOP
111 // disable timer overflow interrupt
112 TIMSK &= ~_BV(TOIE1); // overflow bit?
120 // handle TCNT1 overflow
121 //! Interrupt handler for tcnt1 overflow interrupt
122 ISR(TIMER1_OVF_vect, ISR_NOBLOCK)
125 // handle breathing here
126 #ifdef BACKLIGHT_BREATHING
127 if (is_breathing()) {
128 custom_breathing_handler();
132 // TODO call user defined function
135 // enable timer 1 PWM
137 void timer1PWMBEnable(void) {
138 // turn on channel B (OC1B) PWM output
139 // set OC1B as non-inverted PWM
140 TCCR1A |= _BV(COM1B1);
141 TCCR1A &= ~_BV(COM1B0);
144 // disable timer 1 PWM
146 void timer1PWMBDisable(void) {
147 TCCR1A &= ~_BV(COM1B1);
148 TCCR1A &= ~_BV(COM1B0);
151 void enableBacklight(void) {
152 DDRD |= BACKLIGHT_PORT; // set digital pin 4 as output
153 PORTD |= BACKLIGHT_PORT; // set digital pin 4 to high
156 void disableBacklight(void) {
157 // DDRD &= ~BACKLIGHT_PORT; // set digital pin 4 as input
158 PORTD &= ~BACKLIGHT_PORT; // set digital pin 4 to low
161 void startPWM(void) {
173 void b_led_init_ports(void) {
174 /* turn backlight on/off depending on user preference */
175 #if BACKLIGHT_ON_STATE == 0
176 // DDRx register: sets the direction of Port D
177 // DDRD &= ~BACKLIGHT_PORT; // set digital pin 4 as input
178 PORTD &= ~BACKLIGHT_PORT; // set digital pin 4 to low
180 DDRD |= BACKLIGHT_PORT; // set digital pin 4 as output
181 PORTD |= BACKLIGHT_PORT; // set digital pin 4 to high
187 #ifdef BACKLIGHT_BREATHING
192 void b_led_set(uint8_t level) {
193 if (level > BACKLIGHT_LEVELS) {
194 level = BACKLIGHT_LEVELS;
197 setPWM((int)(TIMER_TOP * (float) level / BACKLIGHT_LEVELS));
200 // called every matrix scan
201 void b_led_task(void) {
202 // do nothing for now
205 void setPWM(uint16_t xValue) {
206 if (xValue > TIMER_TOP) {
209 OCR1B = xValue; // timer1PWMBSet(xValue);
212 #endif // BACKLIGHT_ENABLE