Create bin folder

makefile

@@ -14,6 +14,7 @@ SRCS=src/*.cpp test/main.cpp lib/*/src/*.cpp
 default: build flash
 
 build:
+	mkdir -p bin
 	${CC} ${CFLAGS} -o bin/${TARGET}.bin  ${SRCS}
 	${CC} ${CFLAGS} -o bin/${TARGET}.elf  ${SRCS}
 	${OBJCOPY} -j .text -j .data -O ihex bin/${TARGET}.bin bin/${TARGET}.hex