diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..c241455
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,98 @@
+PRG            = badge
+OBJ            = main.o
+OPTIMIZE       = -Os -std=gnu99
+PROGRAMMER     = usbtiny
+
+MCU_TARGET     = attiny13a
+DEFS           = -DF_CPU=1000000UL
+
+INCLUDES       = -I.
+LIBS           =
+
+#LFUSE          =
+#HFUSE          =
+#EFUSE          =
+
+# You should not have to change anything below here.
+
+CC             = avr-gcc
+DUDE           = avrdude
+
+HOST_CC        = gcc
+HOST_CFLAGS    = -O0 -g
+HOST_LDFLAGS   = 
+
+# Override is only needed by avr-lib build system.
+
+override CFLAGS        = -g -Wall $(OPTIMIZE) -mmcu=$(MCU_TARGET) $(DEFS) $(INCLUDES)
+override LDFLAGS       = -Wl,-Map,$(PRG).map
+
+DUDEFLAGS      = -c $(PROGRAMMER) -p $(MCU_TARGET)
+
+OBJCOPY        = avr-objcopy
+OBJDUMP        = avr-objdump
+
+all: $(PRG).elf lst text eeprom
+
+$(PRG).elf: $(OBJ)
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^ $(LIBS)
+
+clean:
+	rm -rf $(OBJ) $(PRG).elf $(PRG).lst $(PRG).map $(PRG).bin $(PRG).hex $(PRG).srec $(PRG)_eeprom.bin $(PRG)_eeprom.hex $(PRG)_eeprom.srec $(EXTRA_CLEAN_FILES)
+
+lst:  $(PRG).lst
+
+%.lst: %.elf
+	$(OBJDUMP) -h -S $< > $@
+
+# Rules for flashing, EEPROM writing and fuse bit setting
+
+flash: $(PRG).hex $(PRG)_eeprom.hex
+	$(DUDE) $(DUDEFLAGS) -U eeprom:w:$(PRG)_eeprom.hex:i -U flash:w:$(PRG).hex:i
+
+flashprg: $(PRG).hex
+	$(DUDE) $(DUDEFLAGS) -U flash:w:$(PRG).hex:i
+
+flasheep: $(PRG)_eeprom.hex
+	$(DUDE) $(DUDEFLAGS) -U eeprom:w:$(PRG)_eeprom.hex:i
+
+fuse:
+	$(DUDE) $(DUDEFLAGS) -U hfuse:w:$(HFUSE):m -U lfuse:w:$(LFUSE):m -U efuse:w:$(EFUSE):m
+
+# Rules for building the .text rom images
+
+text: hex bin srec
+
+hex:  $(PRG).hex
+bin:  $(PRG).bin
+srec: $(PRG).srec
+
+%.hex: %.elf
+	$(OBJCOPY) -j .text -j .data -O ihex $< $@
+
+%.srec: %.elf
+	$(OBJCOPY) -j .text -j .data -O srec $< $@
+
+%.bin: %.elf
+	$(OBJCOPY) -j .text -j .data -O binary $< $@
+
+# Rules for building the .eeprom rom images
+
+eeprom: ehex ebin esrec
+
+ehex:  $(PRG)_eeprom.hex
+ebin:  $(PRG)_eeprom.bin
+esrec: $(PRG)_eeprom.srec
+
+%_eeprom.hex: %.elf
+	$(OBJCOPY) -j .eeprom --change-section-lma .eeprom=0 -O ihex $< $@ \
+	|| { echo empty $@ not generated; exit 0; }
+
+%_eeprom.srec: %.elf
+	$(OBJCOPY) -j .eeprom --change-section-lma .eeprom=0 -O srec $< $@ \
+	|| { echo empty $@ not generated; exit 0; }
+
+%_eeprom.bin: %.elf
+	$(OBJCOPY) -j .eeprom --change-section-lma .eeprom=0 -O binary $< $@ \
+	|| { echo empty $@ not generated; exit 0; }
+
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..f41ef46
--- /dev/null
+++ b/main.c
@@ -0,0 +1,41 @@
+/**
+ * Copyright CCC Basel 2020.
+ *
+ * This documentation describes Open Hardware and is licensed under the
+ * CERN OHL v. 1.2.
+ *
+ * You may redistribute and modify this documentation under the terms of the
+ * CERN OHL v.1.2. (http://ohwr.org/cernohl).
+ *
+ * This documentation is distributed
+ * WITHOUT ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING OF MERCHANTABILITY,
+ * SATISFACTORY QUALITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Please see the CERN OHL v.1.2 for applicable conditions.
+ */
+
+#include <stdint.h>
+#include <avr/io.h>
+#include <util/delay.h>
+
+void init() {
+	PORTB = 0;
+	DDRB = _BV(PB0) | _BV(PB1) | _BV(PB2) | _BV(PB3) | _BV(PB4);
+}
+
+void loop() {
+	for (uint8_t i = 0; i < 5; i++) {
+		PORTB = _BV(i);
+		_delay_ms(500);
+	}
+}
+
+int main() {
+	init();
+
+	while (1) {
+		loop();
+	}
+
+	return 0;
+}
diff --git a/main.o b/main.o
new file mode 100644
index 0000000..4647e80
Binary files /dev/null and b/main.o differ