7 files changed, 108 insertions(+), 0 deletions(-)

A .gitignore
A build.sh
A check_programmer_ready.sh
A configure_fuses.sh
A pcb_kicad_project.zip
A src/main.c
A upload.sh

@@ 1,2 @@
+blinky_binary
+blinky_binary.hex

@@ 1,5 @@
+avr-gcc -v \
+    -mmcu=attiny85 \
+    -Os -std=gnu99 -Wall \
+    -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums \
+    src/main.c -o blinky_binary

@@ 1,1 @@
+avrdude -p attiny85 -c usbasp

@@ 1,1 @@
+avrdude -v -p attiny85 -c usbasp -U lfuse:w:0x62:m -U hfuse:w:0xdf:m -U efuse:w:0xff:m

@@ 1,93 @@
+#define F_CPU 1000000UL
+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/power.h>
+
+#define EYES_STATE_OPEN 0
+#define EYES_STATE_CLOSING 1
+#define EYES_STATE_CLOSED 2
+#define EYES_STATE_OPENING 3
+uint8_t eyes_state;
+
+#define EYES_CLOSED_DURATION_MS 200
+#define EYES_OPEN_BASE_DURATION_MS 100
+#define EYES_OPENING_DT_US 1500
+#define EYES_CLOSING_DT_US 400
+uint8_t eyes_open_duration_multipliers_index = 0;
+uint16_t eyes_open_duration_multipliers[] = {
+    50, 40, 79, 20, 91, 43, 68, 70, 40, 23, 33,
+};
+size_t eyes_open_duration_multipliers_count;
+
+int
+main(void)
+{
+    // Minimise power usage.
+    power_all_disable();
+    power_timer0_enable();
+
+    // Drive LEDs via PB0.
+    DDRB |= (1 << DDB0);
+
+    // Set waveform mode to fast PWM.
+    TCCR0A |= (1 << WGM00);
+    TCCR0A |= (1 << WGM01);
+    TCCR0B &= ~(1 << WGM02);
+
+    // Set overflow / match behavior.
+    TCCR0A |= (1 << COM0A1);
+    TCCR0A |= (1 << COM0B0);
+    TCCR0A |= (1 << COM0A0);
+    TCCR0A |= (1 << COM0B1);
+
+    // No pre-scaler.
+    TCCR0B |= (1 << CS00);
+
+    // Start with eyes open.
+    OCR0A = 0;
+    eyes_state = EYES_STATE_OPEN;
+
+    // Cache array size.
+    eyes_open_duration_multipliers_count = sizeof(eyes_open_duration_multipliers) / sizeof(eyes_open_duration_multipliers[0]);
+
+    while (1) {
+        switch (eyes_state) {
+
+        case EYES_STATE_OPEN:
+            OCR0A = 0x00;
+            uint16_t duration = eyes_open_duration_multipliers[eyes_open_duration_multipliers_index] * EYES_OPEN_BASE_DURATION_MS;
+            eyes_open_duration_multipliers_index++;
+            if (eyes_open_duration_multipliers_index >= eyes_open_duration_multipliers_count) {
+                eyes_open_duration_multipliers_index = 0;
+            }
+            for (uint16_t i = 0; i < duration; i++) {
+                _delay_ms(1);
+            }
+            eyes_state = EYES_STATE_CLOSING;
+            break;
+
+        case EYES_STATE_CLOSING:
+            OCR0A++;
+            _delay_us(EYES_CLOSING_DT_US);
+            if (OCR0A == 255) {
+                eyes_state = EYES_STATE_CLOSED;
+            }
+            break;
+
+        case EYES_STATE_CLOSED:
+            OCR0A = 0xFF;
+            _delay_ms(EYES_CLOSED_DURATION_MS);
+            eyes_state = EYES_STATE_OPENING;
+            break;
+
+        case EYES_STATE_OPENING:
+            OCR0A--;
+            _delay_us(EYES_OPENING_DT_US);
+            if (OCR0A == 0) {
+                eyes_state = EYES_STATE_OPEN;
+            }
+            break;
+        }
+    }
+    return 0;
+}

@@ 1,6 @@
+if avr-objcopy -O ihex -j.text -j.data blinky_binary blinky_binary.hex
+then
+    avrdude -v -p attiny85 -c usbasp -U flash:w:blinky_binary.hex:i
+else
+    echo "...failed :("
+fi