Implement switches and rotary encoder

firmware/Makefile

@@ -1,10 +1,9 @@
 MCU=atmega88
-CFLAGS=-g -Wall -mcall-prologues -mmcu=$(MCU) -Os -DF_CPU=8000000 -IAVR-SSD1306/Files/
+CFLAGS=-g -Wall -Wno-multichar -Wno-overflow -mcall-prologues -mmcu=$(MCU) -O2 -DF_CPU=8000000 -IAVR-SSD1306/Files/
 LDFLAGS=-Wl,-gc-sections -Wl,-relax
 CC=avr-gcc
 TARGET=main
-_OBJECT_FILES=main.o AVR-SSD1306/Files/SSD1306.c AVR-SSD1306/Files/TWI.c
+OBJECT_FILES=main.o input.o systick.o oled-display/font.o oled-display/i2c.o oled-display/lcd.o
-OBJECT_FILES=main.o oled-display/font.o oled-display/i2c.o oled-display/lcd.o
 
 all: $(TARGET).hex
 

firmware/input.c

@@ -0,0 +1,98 @@
+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/interrupt.h>
+#include "input.h"
+#include "systick.h"
+
+static volatile int8_t rotary_delta = 0;
+static volatile uint8_t sw_event = 0;
+
+void input_init()
+{
+	PORT_ROTARY(DDR) &= ~(PIN_ROTARY_A | PIN_ROTARY_B); // Configure as input
+	PORT_ROTARY(PORT) &= ~(PIN_ROTARY_A | PIN_ROTARY_B); // Set pullups
+
+	PORT_KEYPAD(DDR) &= ~(PIN_KEYPAD_MASK); // Key inputs
+	PORT_KEYPAD(PORT) |= PIN_KEYPAD_MASK; // Key pullups
+}
+
+int8_t get_rotary_delta()
+{
+	int8_t temp = rotary_delta;
+	//rotary_delta = 0;
+	return temp;
+}
+
+static inline void input_proc_rotary()
+{
+	static int8_t last_a;
+	int8_t a;
+	int8_t b;
+	int8_t p;
+
+	p = PORT_ROTARY(PIN);
+	a = (p & PIN_ROTARY_A);
+	b = (p & PIN_ROTARY_B);
+	a = !a;
+	b = !b;
+
+	if (a == 1 && last_a == 0) {
+		_delay_ms(1); // TODO
+		rotary_delta += !!(a ^ b);
+	}
+	if (a == 0 && last_a == 1) {
+		_delay_ms(1); // TODO
+		rotary_delta -= !(a ^ b);
+	}
+
+	last_a = a;
+}
+
+// TODO: Pressing two keys at the same time can lead to unfortunate behavior.
+void input_proc_switches()
+{
+	uint8_t sw;
+	uint8_t ev;
+	uint8_t i;
+	static uint8_t sw_last = 0xFF;
+	uint8_t delta;
+
+	sw = PORT_KEYPAD(PIN) & PIN_KEYPAD_MASK;
+	ev = sw ^ sw_last;
+
+	if (ev) {
+		if (timer_expired(TIMID_SW_DEBOUNCE)) { // If we read a value, wait for the debounce time before we process any other state
+			for (i=0; i < 8; ++i) {
+				if (ev & (1 << i)) {
+					if (sw & (1 << i)) { // Key release
+						if (timer_expired(TIMID_SW_LONGPRESS))
+							i |= (1 << 7) | (1 << 6);
+						else
+							i |= (1 << 7);
+						sw_event = i;
+					} else { // Key push
+						sw_event = 0; // To be honest, I don't have a f*cking clue why I need this...
+						timer_set(TIMID_SW_LONGPRESS, MS_TO_TICKS(1000));
+					}
+					timer_set(TIMID_SW_DEBOUNCE, MS_TO_TICKS(250));
+					break; // We can only process one event at a time anyway, so let's quit it here
+				}
+			}
+		}
+		sw_last = sw;
+	}
+}
+
+uint8_t get_switch_event()
+{
+	uint8_t temp = sw_event;
+	sw_event = 0;
+	return temp;
+}
+
+// Need to call timer_proc() before calling this function!
+void input_proc()
+{
+	input_proc_rotary();
+	input_proc_switches();
+}

firmware/input.h

@@ -0,0 +1,19 @@
+#ifndef INPUT_H
+#define INPUT_H
+
+#define PORT_KEYPAD(t) t##D // Keys connected to: 0,1,2(INT0->POWER),5,6,7
+#define PIN_KEYPAD_MASK 0b11100111
+#define PORT_KEYAUX(t) t##B
+#define PIN_ROTARY_PUSH (1 << 0)
+
+#define PORT_ROTARY(t) t##D
+#define PIN_ROTARY_A (1 << 3) // INT1
+#define PIN_ROTARY_B (1 << 4)
+
+void input_init();
+void input_proc();
+int8_t get_rotary_delta();
+uint8_t get_switch_event();
+extern uint8_t ctime;
+
+#endif // INPUT_H

firmware/main.c

@@ -1,12 +1,24 @@
 #include <avr/io.h>
+#include <avr/interrupt.h>
 #include <avr/pgmspace.h>
-#include <avr/delay.h>
+#include <util/delay.h>
 #include "oled-display/lcd.h"
+#include "input.h"
+#include "systick.h"
 
 #define PORT_SPI(t) t##B
 #define PIN_SPI_CS (1 << 2)
 
-void spi_proc()
+int dbg = 0;
+
+void spi_init()
+{
+	SPCR = (1 << SPE);
+	SPSR = (1 << SPI2X);
+	DDRB |= (1 << 4);
+}
+
+uint8_t spi_proc()
 {
 	static uint8_t new_data = 0;
 	static uint8_t x = 0;
@@ -17,6 +29,9 @@ void spi_proc()
 
 	if (spi_cs) {
 		if (SPSR & (1 << SPIF)) {
+			//SPDR = get_rotary_delta();
+			SPDR = get_switch_event();
+			//SPDR = dbg;
 			lcd_set_buffer(x, y, SPDR);
 			if (y == 0) {
 				y = DISPLAY_HEIGHT / 8 - 1;
@@ -37,9 +52,11 @@ void spi_proc()
 		x = 0;
 		y = DISPLAY_HEIGHT / 8 - 1;
 	}
+
+	return spi_cs;
 }
 
-int main()
+void lcd_startup()
 {
 	lcd_init(LCD_DISP_ON);
 	lcd_gotoxy(0, 0);
@@ -50,13 +67,24 @@ int main()
 	lcd_gotoxy(0, 3);
 	lcd_puts_p(PSTR("Please wait..."));
 	lcd_display();
+}
 
-	SPCR = (1 << SPE);
+int main()
+{
+	cli();
+
+	lcd_startup();
+	spi_init();
+	systick_init();
+	input_init();
 
 	_delay_ms(10);
 
 	while (1) {
-		spi_proc();
+		if (!spi_proc()) {
+			timer_proc();
+			input_proc();
+		}
 	}
 	return 0;
 }

firmware/systick.c

@@ -0,0 +1,66 @@
+#include <avr/io.h>
+#include "systick.h"
+#include <stdlib.h>
+
+uint8_t ctime;
+
+static uint8_t tims[NTIM];
+
+void systick_init()
+{
+	int i;
+
+	TCCR1A = 0;
+	TCCR1B = (1 << CS10) | (1 << CS12); // f_tim = f_clk / 256 -> TCNT1H counts with 8ms / tick
+	TCCR1C = 0;
+	OCR1A = 0x7FFF;
+
+	for (i=0; i < NTIM; ++i) {
+		tims[i] = 0;
+	}
+}
+
+void timer_proc()
+{
+	uint8_t now;
+	uint8_t delta;
+	uint8_t i;
+
+	now = TCNT1L;
+	now = TCNT1H;
+
+	if (now == ctime)
+		return;
+	delta = now - ctime;
+	if (delta > 127)
+		delta -= 128;
+
+	for (i=0; i < NTIM; ++i) {
+		if (tims[i] > delta) {
+			tims[i] -= delta;
+		} else {
+			tims[i] = 0;
+		}
+	}
+
+	ctime = now;
+}
+
+uint8_t timer_expired(uint8_t tim_id)
+{
+	return !tims[tim_id];
+}
+
+void timer_set(uint8_t tim_id, uint8_t ticks)
+{
+	tims[tim_id] = ticks;
+}
+
+uint8_t block_for(uint8_t tim_id, uint8_t ticks)
+{
+	if (timer_expired(tim_id)) {
+		timer_set(tim_id, ticks);
+		return 1;
+	}
+	return 0;
+}

firmware/systick.h

@@ -0,0 +1,19 @@
+#ifndef SYSTICK_H
+#define SYSTICK_H
+#include <avr/io.h>
+
+#define TIMID_SW_DEBOUNCE 0
+#define TIMID_SW_LONGPRESS 1
+#define NTIM 2
+
+#define MS_TO_TICKS(ms) (((ms/1000 * F_CPU/1024) / 256))
+
+#define SYSTICK_VAL TCNT1H
+
+void timer_proc();
+void systick_init();
+uint8_t timer_expired(uint8_t tim_id);
+void timer_set(uint8_t tim_id, uint8_t ticks);
+uint8_t block_for(uint8_t tim_id, uint8_t ticks);
+
+#endif // SYSTICK_H