1 files changed, 3 insertions, 3 deletions
diff --git a/display.h b/display.h
index 68c948f..5c9a4a9 100644
--- a/display.h
+++ b/display.h
@@ -52,9 +52,9 @@ public:
     // PM measurements include particles "up to" that size, but we
     // want to display the values for *that* size
     display.print(" 1.0 "); display.println(data->pm.mc_1p0,1);
-    display.print(" 2.5 "); display.println(data->pm.mc_2p5 - data->pm.mc_1p0,1);
-    display.print(" 4.0 "); display.println(data->pm.mc_4p0 - data->pm.mc_2p5,1);
-    display.print("10.0 "); display.println(data->pm.mc_10p0 - data->pm.mc_4p0,1);
+    display.print(" 2.5 "); display.println(max(0.0f,data->pm.mc_2p5 - data->pm.mc_1p0),1);
+    display.print(" 4.0 "); display.println(max(0.0f,data->pm.mc_4p0 - data->pm.mc_2p5),1);
+    display.print("10.0 "); display.println(max(0.0f,data->pm.mc_10p0 - data->pm.mc_4p0),1);
 
     display.setCursor(120,30);
     display.print("Batt "); display.print(data->batteryVoltage);