Switch from internal clock to crystal + button

8 files changed, 140 insertions, 66 deletions

diff --git a/compile_flags.txt b/compile_flags.txt
index 8720d77..2ec992d 100644
--- a/compile_flags.txt
+++ b/compile_flags.txt
@@ -3,7 +3,7 @@
 -std=gnu99
 -Isrc
 -mmcu=attiny84a
--DF_CPU=1000000L
+-DF_CPU=32768L
 -I/nix/store/ivhsczriimr31rrmly0bcj03gv4qa3q7-avr-libc-avr-2.2.1/avr/include
 -L/nix/store/ivhsczriimr31rrmly0bcj03gv4qa3q7-avr-libc-avr-2.2.1/avr/lib
 -funsigned-char
diff --git a/justfile b/justfile
index a7f3d12..575afa9 100644
--- a/justfile
+++ b/justfile
@@ -5,10 +5,10 @@ default:
   just --choose || true
 
 AVR_LIBC := env("AVR_LIBC", "/usr/lib/avr")
-F_CPU := "1000000"
+F_CPU := "32768"
 MCU := "attiny84a"
 MCU_PART := "attiny84"
-SRC := "./src/main.c"
+SRCS := "./src/main.c ./src/display.c"
 OUTDIR := "./out"
 PROGRAMMER := "arduino"
 UPLOAD_SPEED := "19200"
@@ -18,23 +18,30 @@ CFLAGS := f"-g -Os -std=gnu99 -Isrc -mmcu={{MCU}} -DF_CPU={{F_CPU}}L \
 -I{{AVR_LIBC}}/avr/include -L{{AVR_LIBC}}/avr/lib \
 -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -Wall"
 
-AVRDUDE := f"avrdude -v -p {{MCU_PART}} -c {{PROGRAMMER}} -P {{SERIAL_PORT}} -b {{UPLOAD_SPEED}}"
+AVRDUDE := f"avrdude -v -p {{MCU_PART}} -c {{PROGRAMMER}} -P {{SERIAL_PORT}} -b {{UPLOAD_SPEED}} -F"
 
-build: compile_flags
+build: compile-flags
   mkdir -p {{OUTDIR}}
-  avr-gcc {{CFLAGS}} {{SRC}} -o {{OUTDIR}}/out.elf
+  avr-gcc {{CFLAGS}} {{SRCS}} -o {{OUTDIR}}/out.elf
   avr-objcopy -O ihex -R .eeprom {{OUTDIR}}/out.elf {{OUTDIR}}/out.hex
   du -bh "{{OUTDIR}}/out.hex"
 
-write:
-  [ -f "{{OUTDIR}}/out.hex" ] || (echo "No out.hex. Run build"; exit 1);
+write: build flash
+
+flash: check-hexfile-exists
   {{AVRDUDE}} -U "flash:w:{{OUTDIR}}/out.hex:i"
 
 read:
   {{AVRDUDE}} -F -U flash:r:-:h
 
+write-fuses: check-hexfile-exists
+  {{AVRDUDE}} -U lfuse:w:{{OUTDIR}}/out.elf:e -U hfuse:w:{{OUTDIR}}/out.elf:e -U efuse:w:{{OUTDIR}}/out.elf:e
+
+read-fuse:
+  {{AVRDUDE}} -U lfuse:r:-:h -U hfuse:r:-:h
+
 test:
-  gcc -g -std=gnu99 -Isrc -DF_CPU={{F_CPU}}L -DSTUBBED=1 -I./test/stubbed/ -Wall {{SRC}} -o {{OUTDIR}}/test
+  gcc -g -std=gnu99 -DSTUBBED=1 -I./src -I./test/stubbed/ -Wall -Wno-unused-variable {{SRCS}} -o {{OUTDIR}}/test
   {{OUTDIR}}/test
 
 clean:
@@ -43,5 +50,8 @@ clean:
 format:
   find src/ -iname '*.h' -o -iname '*.c' | xargs clang-format -i
 
-@compile_flags:
+@check-hexfile-exists:
+  [ -f "{{OUTDIR}}/out.hex" ] || (echo "No out.hex. Run build first"; exit 1);
+
+@compile-flags:
   echo '{{CFLAGS}}' | tr ' ' '\n' > ./compile_flags.txt
diff --git a/src/display.c b/src/display.c
new file mode 100644
index 0000000..5f2d7f3
--- /dev/null
+++ b/src/display.c
@@ -0,0 +1,41 @@
+#include <avr/io.h>
+#include <stdint.h>
+#include <util/delay.h>
+
+#include "display.h"
+
+// "_gfedcba"
+// Reversed because a-g is mapped to pa0-6. (pa7 is decimal)
+// Complemented because display is common anode
+const uint32_t digit_masks[] = {
+    0b01000000, 0b01111001, 0b00100100, 0b00110000, 0b00011001,
+    0b00010010, 0b00000010, 0b01111000, 0b00000000, 0b00010000,
+};
+
+void write_digit(uint8_t digit) {
+  if (digit > 9 || digit < 0)
+    return;
+  PORTA = digit_masks[digit];
+}
+
+void write_time(uint16_t hour, uint16_t minute) {
+  uint8_t minute_digit1 = minute % 10;
+  uint8_t minute_digit2 = minute / 10;
+  // unsigned short hour_digit1 = hour % 10;
+  // unsigned short hour_digit2 = hour / 10;
+
+#ifdef STUBBED
+  printf("\r:: %d %d", minute_digit2, minute_digit1);
+  fflush(stdout);
+#endif
+
+  write_digit(minute_digit1);
+  PORTA |= (1 << PA7);
+  _delay_ms(10);
+  PORTA &= ~(1 << PA7);
+
+  write_digit(minute_digit2);
+  PORTB |= (1 << PB2);
+  _delay_ms(10);
+  PORTB &= ~(1 << PB2);
+}
diff --git a/src/display.h b/src/display.h
new file mode 100644
index 0000000..a2bbc79
--- /dev/null
+++ b/src/display.h
@@ -0,0 +1,9 @@
+#ifndef _LOADED_DISPLAY
+#define _LOADED_DISPLAY
+#include <stdint.h>
+
+void write_digit(uint8_t digit);
+
+void write_time(uint16_t hour, uint16_t minute);
+
+#endif
diff --git a/src/main.c b/src/main.c
index c1dc647..fd4a091 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,51 +1,45 @@
 #include <avr/io.h>
+#include <avr/fuse.h>
 #include <stdint.h>
 #include <util/delay.h>
 
-// a b c d e f g decimal
-// Reversed because a-g is mapped to pa0-6. (pa7 is decimal)
-// Complemented because display is common anode
-const uint32_t digits[] = {
-    0b01000000, 0b01111001, 0b00100100, 0b00110000, 0b00011001,
-    0b00010010, 0b00000010, 0b01111000, 0b00000000, 0b00010000,
+#include "display.h"
+
+// Config for attiny84a + 32KHz crystal osc taken from https://github.com/ingepnet/breadboardwatch/blob/master/Makefile#L26
+FUSES = {
+  .low = 0xe6,
+  .high = 0xd7,
+  .extended = 0xff,
 };
 
-void write_digit(uint8_t digit) {
-  if (digit > 9 || digit < 0)
-    return;
-  PORTA = digits[digit];
+void setup_output(void) {
+  DDRA |= 0b11111111;
+  DDRB |= 0b11111111;
 }
 
-void write_time(uint16_t hour, uint16_t minute) {
-  uint8_t minute_digit1 = minute % 10;
-  uint8_t minute_digit2 = minute / 10;
-  // unsigned short hour_digit1 = hour % 10;
-  // unsigned short hour_digit2 = hour / 10;
+int main(void) {
+  uint32_t count = 0;
+  uint8_t is_button_on = 0;
 
-#ifdef STUBBED
-  printf("\r:: %d %d", minute_digit2, minute_digit1);
-  fflush(stdout);
-#endif
+  while (1) {
+    DDRB &= ~(1 << PB2);
+    is_button_on = (PINB & (1 << PB2)) > 0;
 
-  write_digit(minute_digit1);
-  PORTA |= (1 << PA7);
-  _delay_ms(10);
-  PORTA &= ~(1 << PA7);
+    if (is_button_on) {
+      _delay_ms(30);
+      is_button_on = (PINB & (1 << PB2)) > 0;
+      if (is_button_on) {
+        setup_output();
+        PORTA |= 0b10000000;
+        _delay_ms(500);
+        continue;
+      }
+    }
 
-  write_digit(minute_digit2);
-  PORTB |= (1 << PB2);
-  _delay_ms(10);
-  PORTB &= ~(1 << PB2);
-}
+    setup_output();
+    write_time(0, (count / 20) % 60);
 
-int main(void) {
-  DDRA |= 0b11111111;
-  DDRB |= (1 << PB2);
-
-  uint32_t i = 0;
-  while (1) {
-    write_time(0, (i / 20) % 60);
-    i = (i + 1) % 100000;
+    count = (count + 1) % 100000;
   }
   return 0;
 }
diff --git a/test/stubbed/avr/fuse.h b/test/stubbed/avr/fuse.h
new file mode 100644
index 0000000..be579d3
--- /dev/null
+++ b/test/stubbed/avr/fuse.h
@@ -0,0 +1,12 @@
+#ifndef STUB_AVR_FUSE
+#define STUB_AVR_FUSE
+
+struct __fuses_t {
+  int high;
+  int low;
+  int extended;
+};
+
+#define FUSES const struct __fuses_t _watch_mcu_fuses_configuration
+
+#endif
diff --git a/test/stubbed/avr/io.h b/test/stubbed/avr/io.h
index cd4a7bc..cfbdef3 100644
--- a/test/stubbed/avr/io.h
+++ b/test/stubbed/avr/io.h
@@ -1,24 +1,28 @@
+#ifndef STUB_AVR_IO
+#define STUB_AVR_IO
 #include <stdio.h>
 
-int DDRA = 0;
-int DDRB = 0;
+static int DDRA = 0;
+static int DDRB = 0;
 
-int PORTA = 0;
-int PORTB = 0;
+static int PORTA = 0;
+static int PORTB = 0;
+static int PINA = 0;
+static int PINB = 0;
 
-int PA1 = 1;
-int PA2 = 2;
-int PA3 = 3;
-int PA4 = 4;
-int PA5 = 5;
-int PA6 = 6;
-int PA7 = 7;
-
-int PB1 = 1;
-int PB2 = 2;
-int PB3 = 3;
-int PB4 = 4;
-int PB5 = 5;
-int PB6 = 6;
-int PB7 = 7;
+#define PA1 1
+#define PA2 2
+#define PA3 3
+#define PA4 4
+#define PA5 5
+#define PA6 6
+#define PA7 7
 
+#define PB1 1
+#define PB2 2
+#define PB3 3
+#define PB4 4
+#define PB5 5
+#define PB6 6
+#define PB7 7
+#endif
diff --git a/test/stubbed/util/delay.h b/test/stubbed/util/delay.h
index ce4323e..db61690 100644
--- a/test/stubbed/util/delay.h
+++ b/test/stubbed/util/delay.h
@@ -1,5 +1,9 @@
+#ifndef STUB_UTIL_DELAY
+#define STUB_UTIL_DELAY
+
 #include <unistd.h>
 
-void _delay_ms(int ms) {
+static void _delay_ms(int ms) {
   usleep(ms * 1000);
 }
+#endif