diff --git a/ESP-IDF_Robot/main/motor_controls.h b/ESP-IDF_Robot/main/motor_controls.h
index 712d730ee..5097f03c3 100644
--- a/ESP-IDF_Robot/main/motor_controls.h
+++ b/ESP-IDF_Robot/main/motor_controls.h
@@ -21,6 +21,8 @@ static int rescale_raw_val (int raw) {
 
     int s;
     s = 4*raw - 8940;
+    if (s < 0)
+        s = 0;
     return s;
 }