Use correct format specifier in printf for uint32_t

stm-firmware/Makefile

@@ -109,7 +109,9 @@ mrproper: clean
 
 clean:
 	@echo "Cleaning up derived files..."
-	$(QUIET)rm -f $(target).elf $(target).bin $(target).hex $(OBJ) $(ASOBJ) $(mapfile).map $(CFILES:%.c=$(OBJDIR)/%.c.d) $(ASFILES:%.S=$(OBJDIR)/%.S.d)
+	$(QUIET)rm -f $(target).elf $(target).bin $(target).hex $(OBJ) $(ASOBJ) $(mapfile).map $(CFILES:%.c=$(OBJDIR)/%.c.d) $(ASFILES:%.S=$(OBJDIR)/%.S.d) 
+	$(QUIET)rm -rf $(OBJDIR)/*
+
 qtproject:
 	echo -e "TEMPLATE = app\nCONFIG -= console app_bundle qt" > $(target).pro
 	echo -e "SOURCES += $(CFILES) $(ASFILES)" >> $(target).pro

stm-firmware/main.c

@@ -26,6 +26,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <inttypes.h>
 /* #include <arm_math.h> */
 #include <stm32/stm32f4xx.h>
 #include <cmsis/core_cm4.h>
@@ -216,7 +217,7 @@ int main()
 
 
 		rot = rotary_encoder_get_abs_val();
-		snprintf(&disp[0][0], 21U, "Rot-Enc: %u", rot);
+		snprintf(&disp[0][0], 21U, "Rot-Enc: %" PRIu32, rot);
 		strcpy(&disp[1][0], "Line 2");
 		strcpy(&disp[3][0], "Shimatta Reflow");