diff --git a/overlay/opt/emcomm-tools/bin/et-fldigi b/overlay/opt/emcomm-tools/bin/et-fldigi
index b4aa316..2356553 100755
--- a/overlay/opt/emcomm-tools/bin/et-fldigi
+++ b/overlay/opt/emcomm-tools/bin/et-fldigi
@@ -36,7 +36,7 @@ start() {
 
 update-config () {
 
-    # 1. Check if the audio symlink was created by the udev rules
+    # 1. Check if the audio device symlink was created by the udev rules
     if [[ -e /dev/et-audio ]]; then
 
        # 2. Check that this device was properly tagged with the ET_AUDIO env variable 
@@ -56,6 +56,134 @@ update-config () {
       notify_user "Can't start fldigi. No supported audio device plugged in."
       exit 1
     fi
+
+    PORT_AUDIO_CONF=/tmp/conf.tmp
+    GEO_CONF=/tmp/geo.tmp
+    FLDIGI_CONF_DIR="${HOME}/.fldigi"
+    FLDIGI_CONF_FILE="${FLDIGI_CONF_DIR}/fldigi_def.xml"
+
+    if [[ ! -e ${FLDIGI_CONF_DIR} ]]; then
+      et-log "${FLDIGI_CONF_DIR} does not exist. Creating it from template."
+      mkdir -v ${FLDIGI_CONF_DIR}
+      cp -v /etc/skel/.fldigi/fldigi_def.xml ${FLDIGI_CONF_DIR}
+    fi
+
+    [ -z "$ET_USER_CONFIG" ] && ET_USER_CONFIG="${HOME}/.config/emcomm-tools/user.json"
+
+    # clean up temporary config that may exist
+    [[ -e ${PORT_AUDIO_CONF} ]] && rm ${PORT_AUDIO_CONF}
+
+    et-portaudio 2>/dev/null > ${PORT_AUDIO_CONF}
+
+    if [[ $? -ne 0 ]]; then
+      echo "No supported ET_AUDIO device found"
+      exit 1
+    fi
+
+    DEVICE=$(jq -r -e '.device' ${PORT_AUDIO_CONF})
+    if [[ $? -ne 0 ]]; then
+      echo "Error getting PulseAudio device name for ET_AUDIO device"
+      exit 1
+    fi
+
+    INDEX=$(jq -r -e '.index' ${PORT_AUDIO_CONF})
+    if [[ $? -ne 0 ]]; then
+      echo "Error getting PulseAudio device index for ET_AUDIO device"
+      exit 1
+    fi
+
+    ##############################################
+    # Map ALSA ET_AUDIO device to PortAudio device
+    ##############################################
+    et-log "Updating PortAudio device configuration..."
+
+    sed -i "s|^<AUDIOIO>.*|<AUDIOIO>1</AUDIOIO>|" ${FLDIGI_CONF_FILE}
+
+    sed -i "s|^<PORTINDEVICE>.*|<PORTINDEVICE>${DEVICE}</PORTINDEVICE>|" ${FLDIGI_CONF_FILE}
+    sed -i "s|^<PORTININDEX>.*|<PORTININDEX>${INDEX}</PORTININDEX>|" ${FLDIGI_CONF_FILE}
+
+    sed -i "s|^<PORTOUTDEVICE>.*|<PORTOUTDEVICE>${DEVICE}</PORTOUTDEVICE>|" ${FLDIGI_CONF_FILE}
+    sed -i "s|^<PORTOUTINDEX>.*|<PORTOUTINDEX>${INDEX}</PORTOUTINDEX>|" ${FLDIGI_CONF_FILE}
+
+    et-log "Using device '${DEVICE}' and device index '${INDEX}' for PortAudio configuration"
+
+
+    #################
+    # Update callsign
+    #################
+    et-log "Updating callsign configuration..."
+    CALLSIGN=$(jq -r -e '.callsign' ${ET_USER_CONFIG})
+
+    if [[ "${CALLSIGN}" = "N0CALL" ]]; then
+       et-log "Exiting early. No callsign set. Run: et-user."
+       exit 1
+    fi
+
+    et-log "Using callsign '${CALLSIGN}'"
+    sed -i "s|^<MYCALL>.*|<MYCALL>${CALLSIGN}</MYCALL>|" ${FLDIGI_CONF_FILE}
+
+
+    ###############################################
+    # Update grid based on ETC geolocation services
+    ###############################################
+    et-log "Updating your grid square..."
+    curl -f -s "http://localhost:1981/api/geo/position" > ${GEO_CONF}
+
+    if [[ $? -eq 0 ]]; then
+      GRID=$(jq -r -e '.position.gridSquare' ${GEO_CONF})
+      if [[ $? -eq 0 ]]; then
+        et-log "Using grid square '${GRID}' for your location"
+        sed -i "s|^<MYLOC>.*|<MYLOC>${GRID}</MYLOC>|" ${FLDIGI_CONF_FILE}
+      fi
+    fi
+
+    [[ -e ${GEO_CONF} ]] && rm ${GEO_CONF}
+
+
+    #####################################################################
+    # Configure CAT interface using Hamlib's rig control daemon (rigctld)
+    #####################################################################
+    et-log "Updating CAT control configuration..."
+
+    sed -i "s|^<CHKUSEHAMLIBIS>.*|<CHKUSEHAMLIBIS>1</CHKUSEHAMLIBIS>|" ${FLDIGI_CONF_FILE}
+    sed -i "s|^<HAMRIGMODEL>.*|<HAMRIGMODEL>2</HAMRIGMODEL>|" ${FLDIGI_CONF_FILE}
+    sed -i "s|^<HAMLIBCMDPTT>.*|<HAMLIBCMDPTT>1</HAMLIBCMDPTT>|" ${FLDIGI_CONF_FILE}
+    sed -i "s|^<HAMRIGDEVICE>.*|<HAMRIGDEVICE>localhost:4532</HAMRIGDEVICE>|" ${FLDIGI_CONF_FILE}
+
+
+    ######################################
+    # Enable Reed Soloman ID for RX and TX
+    ######################################
+    et-log "Enabling Reed Soloman ID for RX/TX..."
+
+    sed -i "s|^<RECEIVERSID>.*|<RECEIVERSID>1</RECEIVERSID>|" ${FLDIGI_CONF_FILE}
+    sed -i "s|^<TRANSMITRSID>.*|<TRANSMITRSID>1</TRANSMITRSID>|" ${FLDIGI_CONF_FILE}
+
+
+    ###########################
+    # Modem configuration: MT63
+    ###########################
+    et-log "Updating MT63 modem configuration..."
+
+    sed -i "s|^<MT63INTEGRATION>.*|<MT63INTEGRATION>1</MT63INTEGRATION>|" ${FLDIGI_CONF_FILE}
+
+
+    ########################
+    # Repeater configuration
+    ########################
+    et-log "Updating settings for linked repeater systems..."
+
+    # Key up for 2 seconds before transmitting tone. Needed for linked repeater systems.
+    sed -i "s|^<PRETONE>.*|<PRETONE>2</PRETONE>|" ${FLDIGI_CONF_FILE}
+
+
+    #####################
+    # NBEMS configuration
+    #####################
+    et-log "Updating settings for NBEMS..."
+
+    sed -i "s|^<OPEN_NBEMS_FOLDER>.*|<OPEN_NBEMS_FOLDER>1</OPEN_NBEMS_FOLDER>|" ${FLDIGI_CONF_FILE}
+    sed -i "s|^<FLMSG_PATHNAME>.*|<FLMSG_PATHNAME>/usr/local/bin/flmsg</FLMSG_PATHNAME>|" ${FLDIGI_CONF_FILE}
 }
 
 case $1 in