Ignition monitor: Initial commit

Implemented:
* sleep mode
* monitoring portb pin3
* switching portb pin4

Missing:
* shutdown guard time

Makefile

@@ -0,0 +1,75 @@
+CROSS_COMPILE ?= avr-
+
+TARGET_FILE ?= avr.elf
+
+MCU = attiny85
+DUDE_MCU = t85
+
+C_FLAGS += -Wall -Werror
+C_FLAGS += -Os
+C_FLAGS += -mmcu=$(MCU)
+C_FLAGS += -ffunction-sections
+C_FLAGS += -fdata-sections
+C_FLAGS += -std=c11
+C_FLAGS += -pedantic
+C_FLAGS += -pedantic-errors
+C_FLAGS += -Iinclude
+
+DUDE_FLAGS = -p $(DUDE_MCU)
+DUDE_FLAGS += -P /dev/spidev0.0
+DUDE_FLAGS += -c linuxspi
+DUDE_FLAGS += -b 10000
+
+CC = $(CROSS_COMPILE)gcc
+AS = $(CROSS_COMPILE)as
+LD = $(CROSS_COMPILE)ld
+OBJCOPY = $(CROSS_COMPILE)objcopy
+SIZE = $(CROSS_COMPILE)size
+AVRDUDE = avrdude
+
+OBJ_DIR := objs
+BIN_DIR := bin
+SRC_DIR := src
+
+C_SRCS = $(wildcard $(SRC_DIR)/*.c)
+C_OBJS = $(patsubst %.c,$(OBJ_DIR)/%.o,$(notdir $(C_SRCS)))
+
+OBJS = $(C_OBJS)
+TARGET = $(BIN_DIR)/$(TARGET_FILE)
+
+.PHONY: all
+all: $(TARGET)
+
+$(TARGET): $(OBJS) Makefile
+	@mkdir -p $(BIN_DIR)
+	$(CC) $(LD_FLAGS) $(LINKER_SCRIPT) $(OBJS) $(LD_LIBS) -o $@ -Wl,-Map=$(BIN_DIR)/$(notdir $(basename $@)).map
+	$(OBJCOPY) -O ihex $(TARGET) $(subst .elf,.hex,$(TARGET))
+	$(SIZE) $@
+
+$(OBJ_DIR)/%.o: $(SRC_DIR)/%.c
+	@mkdir -p $(dir $@)
+	@$(call makedep,$<,$@,$(patsubst %.c,%.d,$(OBJ_DIR)/$(notdir $<)),$(C_FLAGS))
+	$(CC) -c $(C_FLAGS) $(CCFLAGS) -o $@ $<
+
+.PHONY: clean
+clean:
+	rm -rf \
+	$(OBJS) \
+	$(patsubst %.o,%.d,$(OBJS)) \
+	$(TARGET) \
+	$(subst .elf,.map,$(TARGET)) \
+	$(subst .elf,.hex,$(TARGET))
+
+.PHONY: flash
+flash: $(TARGET)
+	gpio 22 off
+	$(AVRDUDE) $(DUDE_FLAGS) -U flash:w:$(subst .elf,.hex,$(TARGET))
+	gpio 22 on
+
+define makedep
+	$(CC) -MM -MF $3 -MP -MT $2 $4 $1
+endef
+
+ifneq ($(MAKECMDGOALS),clean)
+-include $($(subst .o,.d,$(OBJS))
+endif