diff --git a/stm-firmware/include/reflow-controller/settings/settings-sd-card.h b/stm-firmware/include/reflow-controller/settings/settings-sd-card.h
index c657069..e59d50a 100644
--- a/stm-firmware/include/reflow-controller/settings/settings-sd-card.h
+++ b/stm-firmware/include/reflow-controller/settings/settings-sd-card.h
@@ -21,4 +21,8 @@
 #ifndef __SETTINGS_SETTINGS_SD_CARD_H__
 #define __SETTINGS_SETTINGS_SD_CARD_H__
 
+#define CALIBRATION_FILE_NAME "cal.toml"
+
+int sd_card_settings_save_calibration(float sens_deviation, float offset);
+
 #endif /* __SETTINGS_SETTINGS_SD_CARD_H__ */
diff --git a/stm-firmware/include/reflow-controller/settings/settings.h b/stm-firmware/include/reflow-controller/settings/settings.h
index de4ba2b..4197e69 100644
--- a/stm-firmware/include/reflow-controller/settings/settings.h
+++ b/stm-firmware/include/reflow-controller/settings/settings.h
@@ -22,6 +22,12 @@
 #ifndef __SETTINGS_SETTINGS_H__
 #define __SETTINGS_SETTINGS_H__
 
-int settings_save_calibration();
+/**
+ * @brief Save the calibration
+ * @param sens_deviation
+ * @param offset
+ * @return 0 if successful, -1 if generic error, -2 if medium unavailable
+ */
+int settings_save_calibration(float sens_deviation, float offset);
 
 #endif /* __SETTINGS_SETTINGS_H__ */
diff --git a/stm-firmware/settings/settings-sd-card.c b/stm-firmware/settings/settings-sd-card.c
index 5239091..cb8fc8b 100644
--- a/stm-firmware/settings/settings-sd-card.c
+++ b/stm-firmware/settings/settings-sd-card.c
@@ -19,3 +19,90 @@
 */
 
 #include <reflow-controller/settings/settings-sd-card.h>
+#include <stm-periph/unique-id.h>
+#include <toml/toml.h>
+#include <fatfs/ff.h>
+
+static void get_controller_folder_path(char *path, size_t size)
+{
+	uint32_t high;
+	uint32_t mid;
+	uint32_t low;
+
+	if (!path)
+		return;
+
+	unique_id_get(&high, &mid, &low);
+
+	snprintf(path, size, "/%08X-%08X-%08X",
+		 (unsigned int)high, (unsigned int)mid, (unsigned int)low);
+}
+
+/**
+ * @brief Open or create the controller folder on the SD Card.
+ * @param[in,out] controller_folder
+ * @return 0 if opened, 1 if created and opened, -1 if error.
+ */
+static int open_or_create_controller_folder(DIR *controller_folder)
+{
+	char foldername[48];
+	int ret = -1;
+	FRESULT filesystem_result;
+
+	if (!controller_folder)
+		return -1001;
+
+	get_controller_folder_path(foldername, sizeof(foldername));
+
+	/* Check if folder is present */
+	filesystem_result = f_opendir(controller_folder, foldername);
+	if (filesystem_result == FR_OK) {
+		ret = 0;
+	} else {
+		filesystem_result = f_mkdir(foldername);
+		if (filesystem_result == FR_OK) {
+			filesystem_result = f_opendir(controller_folder, foldername);
+			if (filesystem_result == FR_OK)
+				ret = 1;
+			else
+				ret = -1;
+		} else {
+			ret = -1;
+		}
+	}
+
+	if (ret >= 0)
+		f_chdir(foldername);
+
+	return ret;
+}
+
+int sd_card_settings_save_calibration(float sens_deviation, float offset)
+{
+	DIR folder;
+	FIL cal_file;
+	int status;
+	FRESULT res;
+	UINT bw;
+	int ret = 0;
+
+	status = open_or_create_controller_folder(&folder);
+	f_closedir(&folder);
+
+	if (status < 0)
+		return -2;
+
+	/* Create new calibration file */
+	res = f_open(&cal_file, CALIBRATION_FILE_NAME, FA_CREATE_ALWAYS | FA_WRITE);
+	if (res == FR_OK) {
+		f_write(&cal_file, "Test", 4U, &bw);
+		f_close(&cal_file);
+		ret = 0;
+	} else {
+		ret = -1;
+	}
+
+	f_chdir("/");
+
+	return ret;
+}
diff --git a/stm-firmware/settings/settings.c b/stm-firmware/settings/settings.c
index a93b356..806babc 100644
--- a/stm-firmware/settings/settings.c
+++ b/stm-firmware/settings/settings.c
@@ -19,8 +19,10 @@
 */
 
 #include <reflow-controller/settings/settings.h>
+#include <reflow-controller/settings/settings-sd-card.h>
 
-int settings_save_calibration()
+settings_save_calibration(float sens_deviation, float offset)
 {
-	return 0;
+	/* There is no other configuration location besides the SD card (yet) */
+	return sd_card_settings_save_calibration(sens_deviation, offset);
 }