diff --git a/.gitmodules b/.gitmodules
index 9113d32..fe93929 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "external/CMSIS_5"]
 	path = external/CMSIS_5
 	url = https://github.com/ARM-software/CMSIS_5
+[submodule "external/printf"]
+	path = external/printf
+	url = https://github.com/mpaland/printf
diff --git a/Makefile b/Makefile
index a54597f..e18502c 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,7 @@ OBJS += init.o
 OBJS += overlay.o
 OBJS += $(LINK_OVERLAY).o
 OBJS += $(BLOB_OVERLAY).o
+OBJS += external/printf/printf.o
 
 # Drivers
 OBJS += driver/adc.o
@@ -60,6 +61,7 @@ SIZE = arm-none-eabi-size
 
 ASFLAGS = -mcpu=cortex-m0
 CFLAGS = -O2 -Wall -Werror -mcpu=cortex-m0 -fno-builtin -MMD
+CFLAGS += -DPRINTF_INCLUDE_CONFIG_H
 LDFLAGS = -mcpu=cortex-m0 -nostartfiles -Wl,-T,firmware.ld
 
 OVERLAY_CFLAGS = $(CFLAGS) -fno-inline -fno-toplevel-reorder
diff --git a/external/printf b/external/printf
new file mode 160000
index 0000000..d3b9846
--- /dev/null
+++ b/external/printf
@@ -0,0 +1 @@
+Subproject commit d3b984684bb8a8bdc48cc7a1abecb93ce59bbe3e
diff --git a/printf_config.h b/printf_config.h
new file mode 100644
index 0000000..2518a26
--- /dev/null
+++ b/printf_config.h
@@ -0,0 +1,3 @@
+#define PRINTF_DISABLE_SUPPORT_LONG_LONG
+#define PRINTF_DISABLE_SUPPORT_EXPONENTIAL
+#define PRINTF_DISABLE_SUPPORT_PTRDIFF_T