4 files changed, 27 insertions, 21 deletions
diff --git a/src/common/Core/fsm.c b/src/common/Core/fsm.c
index 52ec8cb..47c349d 100644
--- a/src/common/Core/fsm.c
+++ b/src/common/Core/fsm.c
@@ -520,10 +520,11 @@ void fsm_update() {
                                 " %d AH %c ", capacity_bat_ah, supply_trend);
                     }
 
-                    if (temperature_valid()) {
+                    float temp = 0;
+                    if (temperature_get(&temp)) {
                         len += snprintf(balise_message + len, BALISE_MESSAGE_LEN-len-1,
                                 " T %d ",
-                                (int)(round_float_to_half_steps(temperature_get())));
+                                (int)(round_float_to_half_steps(temp)));
                     }
 
                     snprintf(balise_message + len, BALISE_MESSAGE_LEN-len-1,
@@ -639,10 +640,11 @@ void fsm_update() {
                             " %d AH ", capacity_bat_ah);
                 }
 
-                if (temperature_valid()) {
+                float temp = 0;
+                if (temperature_get(&temp)) {
                     len += snprintf(balise_message + len, BALISE_MESSAGE_LEN-len-1,
                             " T %d ",
-                            (int)(round_float_to_half_steps(temperature_get())));
+                            (int)(round_float_to_half_steps(temp)));
                 }
 
                 len += snprintf(balise_message+len, BALISE_MESSAGE_LEN-len-1,
diff --git a/src/common/Core/main.c b/src/common/Core/main.c
index ea393ab..f525221 100644
--- a/src/common/Core/main.c
+++ b/src/common/Core/main.c
@@ -502,8 +502,8 @@ static void gps_monit_task(void __attribute__ ((unused))*pvParameters) {
                 stats_battery_at_full_hour(time.tm_hour, u_bat, capacity_bat);
             }
 
-            if (temperature_valid()) {
-                float temp = temperature_get();
+            float temp = 0;
+            if (temperature_get(&temp)) {
                 stats_temp(temp);
 
                 const char *sign = "";
diff --git a/src/common/GPIO/temperature.c b/src/common/GPIO/temperature.c
index f9e43cb..54fba80 100644
--- a/src/common/GPIO/temperature.c
+++ b/src/common/GPIO/temperature.c
@@ -30,7 +30,9 @@
 
 
 float _temperature_last_value;
-int _temperature_valid;
+int _temperature_valid_since;
+
+#define TEMP_VALID_DURATION (60*15) // 15 minutes
 
 
 void temperature_task(void *pvParameters);
@@ -47,16 +49,17 @@ void temperature_init() {
         NULL);
 }
 
-// Return the current temperature
-float temperature_get() {
-    if (_temperature_valid) {
-        return _temperature_last_value;
-    } else {
-        return 0.0f;
-    }
+int temperature_valid() {
+    const uint64_t now = timestamp_now();
+    return _temperature_valid_since > 0 && _temperature_valid_since + TEMP_VALID_DURATION < now;
 }
 
-// Return 1 if the temperature is valid
-int temperature_valid() {
-    return _temperature_valid;
+// Return 1 if the the current temperature is valid, and write it into temp
+int temperature_get(float *temp) {
+    if (temperature_valid()) {
+        *temp = _temperature_last_value;
+        return 1;
+    }
+    return 0;
 }
+
diff --git a/src/common/GPIO/temperature.h b/src/common/GPIO/temperature.h
index f49cc26..8d8216f 100644
--- a/src/common/GPIO/temperature.h
+++ b/src/common/GPIO/temperature.h
@@ -26,15 +26,16 @@
 #include <stdint.h>
 
 extern float _temperature_last_value;
-extern int _temperature_valid;
+extern int _temperature_valid_since;
 
 // Setup communication and temperature
 void temperature_init(void);
 
-// Return 1 if the temperature is valid
+// Return 1 if the the current temperature is valid
 int temperature_valid(void);
 
-// Get current temperature
-float temperature_get(void);
+// Return 1 if the the current temperature is valid, and write it into temp
+int temperature_get(float *temp);
+
 
 void temperature_task(void *);