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 << 0) // D0
21 #define CAPSLOCK_PORT (1 << 1) // D1
22 #define BACKLIGHT_PORT (1 << 4) // D4
23 #define SCROLLLOCK_PORT (1 << 6) // D6
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 __attribute__ ((weak))
47 void led_set_user(uint8_t usb_led) {
48 if (usb_led & (1 << USB_LED_NUM_LOCK)) {
51 PORTD |= NUMLOCK_PORT;
54 DDRD &= ~NUMLOCK_PORT;
55 PORTD &= ~NUMLOCK_PORT;
58 if (usb_led & (1 << USB_LED_CAPS_LOCK)) {
59 DDRD |= CAPSLOCK_PORT;
60 PORTD |= CAPSLOCK_PORT;
62 DDRD &= ~CAPSLOCK_PORT;
63 PORTD &= ~CAPSLOCK_PORT;
66 if (usb_led & (1 << USB_LED_SCROLL_LOCK)) {
67 DDRD |= SCROLLLOCK_PORT;
68 PORTD |= SCROLLLOCK_PORT;
70 DDRD &= ~SCROLLLOCK_PORT;
71 PORTD &= ~SCROLLLOCK_PORT;
75 #ifdef BACKLIGHT_ENABLE
77 // sets up Timer 1 for 8-bit PWM
78 void timer1PWMSetup(void) { // NOTE ONLY CALL THIS ONCE
80 TCCR1A &= ~(1 << 1); // cbi(TCCR1A,PWM11); <- set PWM11 bit to HIGH
81 TCCR1A |= (1 << 0); // sbi(TCCR1A,PWM10); <- set PWM10 bit to LOW
83 // clear output compare value A
87 // clear output comparator registers for B
88 OCR1BH = 0; // outb(OCR1BH, 0);
89 OCR1BL = 0; // outb(OCR1BL, 0);
93 void timer1Init(void) {
94 // timer1SetPrescaler(TIMER1PRESCALE)
96 (TCCR1B) = ((TCCR1B) & ~TIMER_PRESCALE_MASK) | TIMER1PRESCALE;
99 TCNT1H = 0; // outb(TCNT1H, 0);
100 TCNT1L = 0; // outb(TCNT1L, 0);
102 // TOIE1: Timer Overflow Interrupt Enable (Timer 1);
103 TIMSK |= _BV(TOIE1); // sbi(TIMSK, TOIE1);
108 void timer1UnInit(void) {
109 // set prescaler back to NONE
110 (TCCR1B) = ((TCCR1B) & ~TIMER_PRESCALE_MASK) | 0x00; // TIMERRTC_CLK_STOP
112 // disable timer overflow interrupt
113 TIMSK &= ~_BV(TOIE1); // overflow bit?
121 // handle TCNT1 overflow
122 //! Interrupt handler for tcnt1 overflow interrupt
123 ISR(TIMER1_OVF_vect, ISR_NOBLOCK)
126 // handle breathing here
127 #ifdef BACKLIGHT_BREATHING
128 if (is_breathing()) {
129 custom_breathing_handler();
133 // TODO call user defined function
136 // enable timer 1 PWM
138 void timer1PWMBEnable(void) {
139 // turn on channel B (OC1B) PWM output
140 // set OC1B as non-inverted PWM
141 TCCR1A |= _BV(COM1B1);
142 TCCR1A &= ~_BV(COM1B0);
145 // disable timer 1 PWM
147 void timer1PWMBDisable(void) {
148 TCCR1A &= ~_BV(COM1B1);
149 TCCR1A &= ~_BV(COM1B0);
152 void enableBacklight(void) {
153 DDRD |= BACKLIGHT_PORT; // set digital pin 4 as output
154 PORTD |= BACKLIGHT_PORT; // set digital pin 4 to high
157 void disableBacklight(void) {
158 // DDRD &= ~BACKLIGHT_PORT; // set digital pin 4 as input
159 PORTD &= ~BACKLIGHT_PORT; // set digital pin 4 to low
162 void startPWM(void) {
174 void b_led_init_ports(void) {
175 /* turn backlight on/off depending on user preference */
176 #if BACKLIGHT_ON_STATE == 0
177 // DDRx register: sets the direction of Port D
178 // DDRD &= ~BACKLIGHT_PORT; // set digital pin 4 as input
179 PORTD &= ~BACKLIGHT_PORT; // set digital pin 4 to low
181 DDRD |= BACKLIGHT_PORT; // set digital pin 4 as output
182 PORTD |= BACKLIGHT_PORT; // set digital pin 4 to high
188 #ifdef BACKLIGHT_BREATHING
193 void b_led_set(uint8_t level) {
194 if (level > BACKLIGHT_LEVELS) {
195 level = BACKLIGHT_LEVELS;
198 setPWM((int)(TIMER_TOP * (float) level / BACKLIGHT_LEVELS));
201 // called every matrix scan
202 void b_led_task(void) {
203 // do nothing for now
206 void setPWM(uint16_t xValue) {
207 if (xValue > TIMER_TOP) {
210 OCR1B = xValue; // timer1PWMBSet(xValue);
213 #endif // BACKLIGHT_ENABLE