From 5aad86cc4eb7232b1cdd2300a25b93a7e013e744 Mon Sep 17 00:00:00 2001
From: Alan Johnston <alan.b.johnston@gmail.com>
Date: Wed, 18 Feb 2026 22:59:24 -0500
Subject: [PATCH] Update packet.sh check and write frequency

---
 groundstation/packet.sh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/groundstation/packet.sh b/groundstation/packet.sh
index cbcd8e3a..a6e4d657 100755
--- a/groundstation/packet.sh
+++ b/groundstation/packet.sh
@@ -182,6 +182,15 @@ echo
           gpio -g write 20 1
           gpio -g mode 21 out  # set PD high
           gpio -g write 21 1
+
+          if [ "$frequency" -gt "450000000" ] || [ "$frequency" -lt "420000000" ] ; then
+
+            echo "Frequency is outside 420 - 450 MHz supported by FM TXC!"
+            echo "Using default frequency of 434.9 MHz"
+            frequency=434900000
+          fi
+
+          python3 /home/pi/CubeSatSim/groundstation/program_fm.py 434900000 $frequency
           
           setsid direwolf -r 48000 -c /home/pi/CubeSatSim/groundstation/direwolf/direwolf-fm-pacsat-jp14-device.conf 
       else