From b204fbef0f0f138b98b85d98cf1e7224e5738f7e Mon Sep 17 00:00:00 2001
From: ThorOdinson246 <110178596+ThorOdinson246@users.noreply.github.com>
Date: Thu, 6 Aug 2026 19:57:04 -0500
Subject: [PATCH] guard against undefined previousValue on first network
 reading

---
 values.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/values.js b/values.js
index 1255e8c..e66687e 100644
--- a/values.js
+++ b/values.js
@@ -421,8 +421,9 @@ export const Values = GObject.registerClass({
                 key: '__' + type + '_ses__',
             });
 
-            // calculate speed for this interface
-            let speed = (value - previousValue[1]) / dwell;
+            // calculate speed for this interface - there is nothing to compare
+            // against the very first time an interface is seen
+            let speed = (previousValue)?(value - previousValue[1]) / dwell:0;
             let speedFormatted = this._legible(speed, 'speed', type);
             output.push({
                 label,