2 * Backlighting code for PS2AVRGB boards (ATMEGA32A)
3 * Kenneth A. (github.com/krusli | krusli.me)
4 Modified by Wayne K Jones (github.com/WarmCatUK) 2018
10 #include <avr/pgmspace.h>
11 #include <avr/interrupt.h>
13 #include "backlight_custom.h"
14 #include "breathing_custom.h"
20 // Port D: digital pins of the AVR chipset
21 //#define NUMLOCK_PORT (1 << 2) // 2nd pin of Port D (digital)
22 #define CAPSLOCK_PORT (1 << 1) // 1st pin
23 #define BACKLIGHT_PORT (1 << 4) // 4th pin
24 //#define SCROLLLOCK_PORT (1 << 6) // 6th pin
26 #define TIMER_CLK_DIV64 0x03 ///< Timer clocked at F_CPU/64
27 #define TIMER1PRESCALE TIMER_CLK_DIV64 ///< timer 1 prescaler default
29 #define TIMER_PRESCALE_MASK 0x07 ///< Timer Prescaler Bit-Mask
32 #define TIMER_TOP 255 // 8 bit PWM
34 extern backlight_config_t backlight_config;
38 * Port Registers: https://www.arduino.cc/en/Reference/PortManipulation
39 * TCCR1A: https://electronics.stackexchange.com/questions/92350/what-is-the-difference-between-tccr1a-and-tccr1b
40 * Timers: http://www.avrbeginners.net/architecture/timers/timers.html
41 * 16-bit timer setup: http://sculland.com/ATmega168/Interrupts-And-Timers/16-Bit-Timer-Setup/
42 * PS2AVRGB firmware: https://github.com/showjean/ps2avrU/tree/master/firmware
46 // turn LEDs on and off depending on USB caps/num/scroll lock states.
47 void led_set_user(uint8_t usb_led) {
49 if (usb_led & (1 << USB_LED_NUM_LOCK)) {
52 PORTD |= NUMLOCK_PORT;
55 DDRD &= ~NUMLOCK_PORT;
56 PORTD &= ~NUMLOCK_PORT;
59 if (usb_led & (1 << USB_LED_CAPS_LOCK)) {
60 DDRD |= CAPSLOCK_PORT;
61 PORTD |= CAPSLOCK_PORT;
63 DDRD &= ~CAPSLOCK_PORT;
64 PORTD &= ~CAPSLOCK_PORT;
67 if (usb_led & (1 << USB_LED_SCROLL_LOCK)) {
68 DDRD |= SCROLLLOCK_PORT;
69 PORTD |= SCROLLLOCK_PORT;
71 DDRD &= ~SCROLLLOCK_PORT;
72 PORTD &= ~SCROLLLOCK_PORT;
77 #ifdef BACKLIGHT_ENABLE
79 // sets up Timer 1 for 8-bit PWM
80 void timer1PWMSetup(void) { // NOTE ONLY CALL THIS ONCE
82 TCCR1A &= ~(1 << 1); // cbi(TCCR1A,PWM11); <- set PWM11 bit to HIGH
83 TCCR1A |= (1 << 0); // sbi(TCCR1A,PWM10); <- set PWM10 bit to LOW
85 // clear output compare value A
89 // clear output comparator registers for B
90 OCR1BH = 0; // outb(OCR1BH, 0);
91 OCR1BL = 0; // outb(OCR1BL, 0);
95 void timer1Init(void) {
96 // timer1SetPrescaler(TIMER1PRESCALE)
98 (TCCR1B) = ((TCCR1B) & ~TIMER_PRESCALE_MASK) | TIMER1PRESCALE;
101 TCNT1H = 0; // outb(TCNT1H, 0);
102 TCNT1L = 0; // outb(TCNT1L, 0);
104 // TOIE1: Timer Overflow Interrupt Enable (Timer 1);
105 TIMSK |= _BV(TOIE1); // sbi(TIMSK, TOIE1);
110 void timer1UnInit(void) {
111 // set prescaler back to NONE
112 (TCCR1B) = ((TCCR1B) & ~TIMER_PRESCALE_MASK) | 0x00; // TIMERRTC_CLK_STOP
114 // disable timer overflow interrupt
115 TIMSK &= ~_BV(TOIE1); // overflow bit?
123 // handle TCNT1 overflow
124 //! Interrupt handler for tcnt1 overflow interrupt
125 ISR(TIMER1_OVF_vect, ISR_NOBLOCK)
128 // handle breathing here
129 #ifdef BACKLIGHT_BREATHING
130 if (is_breathing()) {
131 custom_breathing_handler();
135 // TODO call user defined function
138 // enable timer 1 PWM
140 void timer1PWMBEnable(void) {
141 // turn on channel B (OC1B) PWM output
142 // set OC1B as non-inverted PWM
143 TCCR1A |= _BV(COM1B1);
144 TCCR1A &= ~_BV(COM1B0);
147 // disable timer 1 PWM
149 void timer1PWMBDisable(void) {
150 TCCR1A &= ~_BV(COM1B1);
151 TCCR1A &= ~_BV(COM1B0);
154 void enableBacklight(void) {
155 DDRD |= BACKLIGHT_PORT; // set digital pin 4 as output
156 PORTD |= BACKLIGHT_PORT; // set digital pin 4 to high
159 void disableBacklight(void) {
160 // DDRD &= ~BACKLIGHT_PORT; // set digital pin 4 as input
161 PORTD &= ~BACKLIGHT_PORT; // set digital pin 4 to low
164 void startPWM(void) {
176 void b_led_init_ports(void) {
177 /* turn backlight on/off depending on user preference */
178 #if BACKLIGHT_ON_STATE == 0
179 // DDRx register: sets the direction of Port D
180 // DDRD &= ~BACKLIGHT_PORT; // set digital pin 4 as input
181 PORTD &= ~BACKLIGHT_PORT; // set digital pin 4 to low
183 DDRD |= BACKLIGHT_PORT; // set digital pin 4 as output
184 PORTD |= BACKLIGHT_PORT; // set digital pin 4 to high
190 #ifdef BACKLIGHT_BREATHING
195 void b_led_set(uint8_t level) {
196 if (level > BACKLIGHT_LEVELS) {
197 level = BACKLIGHT_LEVELS;
200 setPWM((int)(TIMER_TOP * (float) level / BACKLIGHT_LEVELS));
203 // called every matrix scan
204 void b_led_task(void) {
205 // do nothing for now
208 void setPWM(uint16_t xValue) {
209 if (xValue > TIMER_TOP) {
212 OCR1B = xValue; // timer1PWMBSet(xValue);
215 #endif // BACKLIGHT_ENABLE