feat(ex01): done

ex01/Makefile

@@ -0,0 +1,55 @@
+# Makefile
+MCU=atmega328p
+F_CPU=16000000
+CC=avr-gcc
+OBJCOPY=avr-objcopy
+CFLAGS=-std=c99 -Wall -Wextra -g -Os -mmcu=$(MCU) -DF_CPU=$(F_CPU) -Iinclude
+IFLAGS=
+TARGET=main
+SERIAL=-P /dev/ttyUSB0 -b 115200
+
+
+SRC_DIR=src
+OBJ_DIR=build
+
+SRC_FILES=main.c utils.c
+OBJ_FILES=$(patsubst %.c,%.o,$(SRC_FILES))
+
+SRC=$(addprefix $(SRC_DIR)/,$(SRC_FILES))
+OBJ=$(addprefix $(OBJ_DIR)/,$(OBJ_FILES))
+
+ELF_FILE=$(OBJ_DIR)/$(TARGET).elf
+HEX_FILE=$(OBJ_DIR)/$(TARGET).hex
+
+all: flash
+
+re: fclean all
+
+fclean: clean
+	rm -f $(HEX_FILE)
+	rm -f $(ELF_FILE)
+clean:
+	rm -rf $(OBJ_DIR)
+
+hex: $(HEX_FILE)
+
+flash: hex
+	avrdude -p $(MCU) -c arduino -U flash:w:$(HEX_FILE):i $(SERIAL) 
+
+
+$(OBJ_DIR)/%.o: $(SRC_DIR)/%.c 
+	@mkdir -p $(shell dirname $@)
+	$(CC) $(CFLAGS) $(IFLAGS) -c $< -o $@
+
+$(ELF_FILE): $(OBJ)
+	$(CC) $(CFLAGS) $(OBJ) -o $@
+
+$(HEX_FILE): $(ELF_FILE)
+	$(OBJCOPY) -j .text -j .data -O ihex $< $@
+
+print:
+	@echo $(SRC)
+	@echo $(OBJ)
+	@echo $(ELF_FILE)
+	@echo $(HEX_FILE)
+

ex01/include/mystd.h

@@ -0,0 +1,15 @@
+#ifndef MYSTDINT_H
+#define MYSTDINT_H
+
+typedef unsigned int uint16_t;
+typedef signed int	 int16_t;
+
+typedef unsigned char uint8_t;
+typedef signed char	  int8_t;
+
+typedef uint8_t bool;
+
+#define true  (1)
+#define false (0)
+
+#endif /* MYSTDINT_H */

ex01/include/utils.h

@@ -0,0 +1,10 @@
+#ifndef UTILS_H
+#define UTILS_H
+
+#include "mystd.h"
+
+void delay_ms(uint16_t count);
+
+void ft_bzero(void *data, uint16_t size);
+
+#endif /* UTILS_H */

ex01/src/main.c

@@ -0,0 +1,51 @@
+#include <avr/interrupt.h>
+#include <avr/io.h>
+
+#include "mystd.h"
+#include "utils.h"
+
+#define D5_R PD5
+#define D5_G PD6
+#define D5_B PD3
+
+#define RGB_MASK (_BV(D5_R) | _BV(D5_G) | _BV(D5_B))
+
+/*
+name    R# G# B#
+red     ff 0  0
+green   0  ff 0
+blue    0  0  ff
+
+yellow  ff ff 0
+cyan    0  ff ff
+magenta ff 0  ff
+
+white   ff ff ff
+*/
+#define COL_RED (_BV(D5_R))
+#define COL_GREEN (_BV(D5_G))
+#define COL_BLUE (_BV(D5_B))
+
+#define COL_YELLOW (_BV(D5_R) | _BV(D5_G))
+#define COL_CYAN (_BV(D5_G) | _BV(D5_B))
+#define COL_MAGENTA (_BV(D5_R) | _BV(D5_B))
+
+#define COL_WHITE (_BV(D5_R) | _BV(D5_G) | _BV(D5_B))
+
+int main(void) {
+  DDRD |= RGB_MASK;
+
+  PORTD = (PORTD & ~RGB_MASK);
+
+  uint8_t colors[7] = {
+      COL_RED,  COL_GREEN,   COL_BLUE,  COL_YELLOW,
+      COL_CYAN, COL_MAGENTA, COL_WHITE,
+  };
+
+  while (1) {
+    for (uint8_t i = 0; i < 7; i++) {
+      PORTD = (PORTD & ~RGB_MASK) | colors[i];
+      delay_ms(1000);
+    }
+  }
+}

ex01/src/utils.c

@@ -0,0 +1,28 @@
+#include "utils.h"
+
+// this just burns cycles.
+// the volatile is important, it means that the cpu can't optimize any
+// read/writes for the value
+static inline void spin_loop(volatile uint16_t counts) {
+	while (counts)
+		counts--;
+}
+
+void delay_ms(uint16_t ms) {
+	while (ms) {
+		// this value was taken using a delay of 500ms, and just recording the led
+		// blinking. it seems to be high enough such that each loop of delay_loop
+		// takes 1ms :D
+		spin_loop((F_CPU) / 5000);
+		ms--;
+	}
+}
+
+void ft_bzero(void* data, uint16_t size) {
+	char* d = data;
+	while (size) {
+		*d = 0;
+		d++;
+		size--;
+	}
+}