diff --git a/stm-firmware/main.c b/stm-firmware/main.c
index ad93dae..e804f77 100644
--- a/stm-firmware/main.c
+++ b/stm-firmware/main.c
@@ -44,6 +44,7 @@
 #include <fatfs/ff.h>
 #include <reflow-controller/reflow-menu.h>
 #include <reflow-controller/safety/safety-controller.h>
+#include <reflow-controller/settings/settings.h>
 
 static void setup_nvic_priorities(void)
 {
@@ -191,7 +192,12 @@ static void zero_ccm_ram(void)
 
 int main(void)
 {
+	bool cal_active;
+	float offset;
+	float sens;
+	int status;
 	bool sd_card_mounted = false;
+	bool sd_old;
 	shellmatta_handle_t shell_handle;
 	int menu_wait_request;
 	uint64_t quarter_sec_timestamp = 0ULL;
@@ -204,7 +210,25 @@ int main(void)
 	while (1) {
 
 		if (systick_ticks_have_passed(quarter_sec_timestamp, 250)) {
+			sd_old = sd_card_mounted;
 			sd_card_mounted = mount_sd_card_if_avail(sd_card_mounted);
+
+			if (sd_old != sd_card_mounted) {
+				led_set(0, 1);
+			} else {
+				led_set(0, 0);
+			}
+
+			if (sd_card_mounted && !sd_old) {
+				adc_pt1000_get_resistance_calibration(NULL, NULL, &cal_active);
+				if (!cal_active) {
+					status = settings_load_calibration(&sens, &offset);
+					if (!status) {
+						adc_pt1000_set_resistance_calibration(offset, sens, true);
+					}
+				}
+			}
+
 			quarter_sec_timestamp = systick_get_global_tick();
 		}