bleh

lib/7segment.c

@@ -1,40 +0,0 @@
-#include <avr/io.h>
-#include <stdbool.h>
-
-/**
- * Display pins should be mapped like this:
- * a  b  c  d  e  f  g  DP
- * 0  1  2  3  4  5  6  7
- * 
- * d1 d2 d3 d4
- * 0  1  2  3
-*/
-
-void set_display_raw(volatile uint8_t * header, uint8_t data) {
-    *header = data;
-}
-
-uint8_t digit_to_binary(bool period, uint8_t digit) {
-    uint8_t val = period << 7;
-
-    switch(digit) {
-        case 0: return val | 0x3f;
-        case 1: return val | 0x06;
-        case 2: return val | 0x5b;
-        case 3: return val | 0x4f;
-        case 4: return val | 0x66;
-        case 5: return val | 0x6d;
-        case 6: return val | 0x7d;
-        case 7: return val | 0x07;
-        case 8: return val | 0x7f;
-        case 9: return val | 0x6f;
-        // by default draw a dash
-        default: return 0b01000000;
-    }
-}
-
-void set_display(volatile uint8_t * header, uint8_t value, bool period) {
-    uint8_t byte = digit_to_binary(period, value);
-
-    set_display_raw(header, byte);
-}

lib/7segment.h

@@ -1,7 +0,0 @@
-#include <avr/io.h>
-
-void set_display_raw(volatile uint8_t * header, uint8_t data);
-
-void set_display(volatile uint8_t * header, uint8_t value, bool period);
-
-uint8_t digit_to_binary(bool period, uint8_t digit);

lib/7segment_4digits.c

@@ -1,59 +0,0 @@
-#include <avr/io.h>
-#include <stdbool.h>
-#include <util/delay.h>
-#include <math.h>
-#include "util.h"
-#include "7segment.h"
-
-uint8_t display[4] = { 0, 0, 0, 0 };
-uint8_t current_digit = 0;
-
-void display_value(uint8_t digit, uint8_t data) {
-    // The left part sets the last 4 bits high (turns the
-    // according digit off) except for the one we want to address.
-    // The right part makes sure the first 4 bits remain unchanged.
-    PORTK = (0b00001111 & ~(1 << digit)) | (PORTK & 0b11110000);
-
-    PORTF = data;
-}
-
-void set_display_value(uint8_t digit, uint8_t data) {
-    display[digit] = data;
-}
-
-void update_next_digit() {
-    update_display_digit(current_digit++);
-    if (current_digit >= 4) current_digit = 0;
-}
-
-void update_display_digit(int digit) {
-    display_value(digit, display[digit]);
-}
-
-// Returns the amount of microseconds we blocked for
-float update_display_all_sync() {
-    int sleep_time = 2000;
-    for (int i = 0; i < 4; i++) {
-        display_value(i, display[i]);
-        _delay_us(sleep_time);
-    }
-    return sleep_time * 4;
-}
-
-void show_float(float value) {
-    if (value >= 10000 || value < 0) {
-        for (int i = 0; i < 4; i++) {
-            set_display_value(i, 0b01000000); // minus character
-        }
-        return;
-    }
-
-    int digits = num_digits((int)value);
-    int full_number = value * (int)roundf(powf(10, 4 - digits));
-
-    for (int i = 0; i < 4; i++) {
-        bool show_period = digits == i + 1;
-        int digit = get_digit_at_position(full_number, 3 - i);
-        set_display_value(i, digit_to_binary(show_period, digit));
-    }
-}

lib/7segment_4digits.h

@@ -1,13 +0,0 @@
-#include <avr/io.h>
-
-void display_value(uint8_t digit, uint8_t data);
-
-void set_display_value(uint8_t digit, uint8_t data);
-
-void update_next_digit();
-
-void update_display_digit(int digit);
-
-float update_display_all_sync();
-
-void show_float(float value);

lib/util.c

@@ -1,31 +0,0 @@
-int num_digits(int num) {
-    if (num < 0) num = -num;
-    if (num >= 10) return num_digits(num / 10) + 1;
-    return 1;
-}
-
-int get_digit_at_position(int number, int index) {
-    if (index < 0) {
-        return -1;
-    }
-    
-    int divisor = 1;
-    int tempNumber = number;
-    while (tempNumber >= 10) {
-        tempNumber /= 10;
-        divisor *= 10;
-    }
-    
-    if (index >= divisor) {
-        return -1;
-    }
-    
-    for (int i = 0; i < index; i++) {
-        number /= 10;
-    }
-    
-    int digit = number % 10;
-    
-    return digit;
-}
-

lib/util.h

@@ -1,3 +0,0 @@
-int num_digits(int num);
-
-int get_digit_at_position(int number, int index);

main.c

@@ -1,29 +1,62 @@
 #define __AVR_ATmega2560__
 #define F_CPU 16000000UL
-#define TICK_BEEP false
 
 #include <avr/io.h>
 #include <util/delay.h>
 #include <stdbool.h>
 #include <avr/interrupt.h>
-#include "lib/util.h"
-#include "lib/7segment.h"
-#include "lib/7segment_4digits.h"
 
-int tick_timer_start =  0xffff - (F_CPU / 1024 / 1000); // 1ms
-volatile uint32_t ticks = 0;
-volatile beep_time = 0;
-volatile bool counting = false;
+volatile uint16_t tick_timer_start = 0xffff - (F_CPU / 1024 / 1000);
+volatile bool speaker_disabled = true;
 
-void start_timer() {
-    // Sets the Clock Select. See table on page 157 the Atmel datasheet.
+uint16_t notes[][3] = {
+    { 1000, 200, 30 },
+    { 1200, 200, 30 },
+    { 1500, 200, 30 },
+    { 1600, 200, 30 },
+    { 1500, 200, 30 },
+    { 1200, 100, 10 },
+    { 1000, 300, 100 },
+};
+
+void ADC_Setup() {
+    // AVCC with external capacitor at AREF pin
+    ADMUX = _BV(REFS0);
+
+    // Enable ADC, set prescaler to 8tick_timer_start
+    ADCSRA = _BV(ADEN) | _BV(ADPS0) | _BV(ADPS1);
+
+    // Perform dummy readout
+    ADCSRA |= _BV(ADSC); // Start conversion
+    while (ADCSRA & _BV(ADSC)); // Await result
+    (void) ADCW; // Read out result
+}
+
+uint16_t ADC_Read(uint8_t channel) {
+    // Select chosen channel
+    ADMUX = (ADMUX & ~(0x1F)) | (channel & 0x1F);
+    // Start conversion
+    ADCSRA |= _BV(ADSC);
+    // Await the result
+    while (ADCSRA & _BV(ADSC));
+    // Although it doesn't appear to be documented, ADCW holds the covnersion result
+    return ADCW;
+}
+
+uint16_t ADC_Read_Avg(uint8_t channel, uint8_t samples) {
+    uint32_t sum = 0;
+    for (int i = 0; i < samples; i++) {
+        sum += ADC_Read(channel);
+    }
+    return (uint16_t)(sum / samples);
+}
+
+void TIMER_Setup() {
     TCCR1B |= _BV(CS10) | _BV(CS12); // clk/1024
-    TCCR2B |= _BV(CS22); // clk/64
 
     // Set the TOIE (Timer Overflow Interrupt Enable) bit
     // on TIMSK1 (Timer 1 Interrupt Mask Register).
     TIMSK1 |= _BV(TOIE1);
-    TIMSK2 |= _BV(TOIE2);
 
     // Sets the current timer value
     TCNT1 = tick_timer_start;
@@ -36,56 +69,37 @@ void start_timer() {
 // is triggered whenever timer 1 (16 bit) overflows.
 ISR(TIMER1_OVF_vect) {
     TCNT1 = tick_timer_start;
-    if (counting) {
-        ticks += 1;
-        if (TICK_BEEP && ticks % 1000 == 0 && !beep_time) beep_time = 10;
+    PORTB ^= 0b10000000;
+
+    if (speaker_disabled) PORTK &= 0b11111110;
+    else PORTK ^= 0b00000001;
 }
 
-    if (bit_is_set(PIND, PIND0)) {
-        PORTD &= 0b11111110;
-    } else if (beep_time > 0) {
-        PORTD |= 0b00000001;
-        beep_time--;
-    }
-}
-
-ISR(TIMER2_OVF_vect) {
-    update_next_digit();
-}
-
-void beep() {
-    beep_time = 50;
+void play_note(uint16_t freq, uint8_t delay, uint8_t delay_silence) {
+    speaker_disabled = false;
+    tick_timer_start = 0xffff - (F_CPU / freq / 1000);
+    for (int i = 0; i < delay; i++) _delay_ms(1);
+    speaker_disabled = true;
+    for (int i = 0; i < delay_silence; i++) _delay_ms(1);
 }
 
 void main() {
-    DDRF  = 0b11111111;
-    DDRK  = 0b00001111;
-    DDRD  = 0b00000001;
-    PORTK = 0b11000000; // set pull-up
+    DDRK = 0b00000001;
+    PORTB = 0b10000000; // Start with LED enabled
 
-    start_timer();
+    ADC_Setup();
+    TIMER_Setup();
 
-    float num = 0.0f;
-    bool pressed_pause = false;
-    bool pressed_clear = false;
+    //long rows = sizeof(notes) / sizeof(notes[0]);
 
-    while(1) {
-        show_float(ticks / 1000.0f);
+    while (true) {
+        //for (int i = 0; i < rows; i++) {
+        //    play_note(notes[i][0], notes[i][1], notes[i][2]);
+        //}
 
-        if (!pressed_pause && bit_is_clear(PINK, PINK7)) {
-            counting = !counting;
-            pressed_pause = true;
-            beep();
-        } else if (pressed_pause && bit_is_set(PINK, PINK7)) {
-            pressed_pause = false;
-        }
-
-        if (bit_is_clear(PINK, PINK6)) {
-            ticks = 0;
-            counting = false;
-
-            if (!pressed_clear) beep();
-            pressed_clear = true;
-        } else pressed_clear = false;
+        uint16_t value = ADC_Read_Avg(0, 4);
+        speaker_disabled = value == 0;
+        if  (value < 100) value = 100; // Anything lower than this causes issues
+        tick_timer_start = 0xffff - (F_CPU / value / 1000);
     }
 }