Added custom frequency offset setting to network reporting

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/model/Constants.kt

@@ -0,0 +1,23 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.core.domain.model
+
+object Constants {
+    const val FREQ_OFFSET_MIN_HZ = -50_000L
+    const val FREQ_OFFSET_MAX_HZ = 50_000L
+}

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/model/Settings.kt

@@ -41,6 +41,7 @@ data class RCSettings(
     val frequencyAddress: String,
     val frequencyPort: String,
     val frequencyFormat: String,
+    val frequencyOffsetHz: Long = 0L,
     val bluetoothRotatorState: Boolean,
     val bluetoothRotatorFormat: String,
     val bluetoothRotatorName: String,

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/utility/Extensions.kt

@@ -41,6 +41,21 @@ fun Double.round(decimals: Int): Double {
     return kotlin.math.round(this * multiplier) / multiplier
 }
 
+fun String.aprsPasscode(): Int {
+    val callsign = this.trim().uppercase().substringBefore('-') // commonly strip SSID
+    var hash = 0x73E2
+    var i = 0
+    while (i < callsign.length) {
+        hash = hash xor (callsign[i].code shl 8)
+        i++
+        if (i < callsign.length) {
+            hash = hash xor callsign[i].code
+            i++
+        }
+    }
+    return hash and 0x7FFF
+}
+
 //fun String.getHash(type: String = "SHA-256"): String {
 //    val hexChars = "0123456789ABCDEF"
 //    val bytes = MessageDigest.getInstance(type).digest(this.toByteArray())

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/DataParserTest.kt

@@ -18,6 +18,7 @@
 package com.rtbishop.look4sat.core.domain
 
 import com.rtbishop.look4sat.core.domain.utility.DataParser
+import com.rtbishop.look4sat.core.domain.utility.aprsPasscode
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.test.StandardTestDispatcher
 import kotlinx.coroutines.test.runTest
@@ -239,4 +240,10 @@ class DataParserTest {
         // Matches the CSV test data epoch: 2021-11-16 → day 320
         assert(dataParser.getDayOfYear(2021, 11, 16) == 320)
     }
+
+    @Test
+    fun `check APRS passcode calculation`() {
+        assert("M7LNB".aprsPasscode() == 12443)
+        assert("N0CALL".aprsPasscode() == 13023)
+    }
 }