Internal "use application fromatter" couts gps sats wrong on ttnmapper webhook

[g6094199]

dont know where to put it, so feel free to move the report

Summary

when sending gps data for mapping the sat count is always 198, despite the real count

Environment

• use preset ttn mapper webhook

Steps to Reproduce

send data like so:

txBuffer[0] = (LatitudeBinary >> 16) & 0xFF;
txBuffer[1] = (LatitudeBinary >> 8) & 0xFF;
txBuffer[2] = LatitudeBinary & 0xFF;

txBuffer[3] = (LongitudeBinary >> 16) & 0xFF;
txBuffer[4] = (LongitudeBinary >> 8) & 0xFF;
txBuffer[5] = LongitudeBinary & 0xFF;

altitudeGps = altitude;
txBuffer[6] = (altitudeGps >> 8) & 0xFF;
txBuffer[7] = altitudeGps & 0xFF;

hdopGps = hdop / 10;
//Serial.println(hdopGps);
txBuffer[8] = hdopGps & 0xFF;
// also sent satellite count
txBuffer[9] = sats & 0xFF;

What do you see now?

"uplink_message": {
  "session_key_id": "AZ/cpTP6NTzNw==",
  "f_port": 1,
  "f_cnt": 3,
  "frm_payload": "xu2AM0hAw==",
  "decoded_payload": {
    "altitude": 205,
    "hdop": 3.3,
    "latitude": 4.7310121,
    "longitude": 9..926,
    "sats": 198
  },

What do you want to see instead?

when i add my custon made decoder :

function decodeUplink(input) {
var bytes = input.bytes;
var errors = [];

// Sicherheits-Check: Hat das Paket wirklich die erwarteten 10 Bytes?
if (bytes.length !== 10) {
return {
errors: ["Ungültige Paketlänge: Erwartet 10 Bytes, erhalten " + bytes.length]
};
}

// 1. Unsigned 24-Bit Integer für Latitude zusammensetzen (Bytes 0, 1, 2)
var latBin = ((bytes[0] << 16) | (bytes[1] << 8) | bytes[2]) >>> 0;
// Rückberechnung laut Arduino-Formel: ((val / 16777215) * 180) - 90
var lat = (latBin / 16777215.0) * 180.0 - 90.0;

// 2. Unsigned 24-Bit Integer für Longitude zusammensetzen (Bytes 3, 4, 5)
var lonBin = ((bytes[3] << 16) | (bytes[4] << 8) | bytes[5]) >>> 0;
// Rückberechnung laut Arduino-Formel: ((val / 16777215) * 360) - 180
var lon = (lonBin / 16777215.0) * 360.0 - 180.0;

// 3. Altitude (Höhe) extrahieren (Bytes 6, 7)
var alt = (bytes[6] << 8) | bytes[7];

// 4. HDOP extrahieren (Byte 8) und zurückskalieren
var hdopValue = bytes[8] / 10.0;

// 5. Satellitenanzahl extrahieren (Byte 9)
var satsCount = bytes[9];

// Plausibilitäts-Check: Koordinaten von genau 0.0000/0.0000 abfangen
if (latBin === 0 && lonBin === 0) {
errors.push("GPS-Modul hat noch keinen gültigen Fix (0.0/0.0 empfangen)");
}

// Berechnete Schätzung für 'accuracy' in Metern (HDOP * 5)
var accuracyMeters = Math.round(hdopValue * 5.0 * 10) / 10;

return {
data: {
latitude: Math.round(lat * 1000000) / 1000000, // Auf 6 Nachkommastellen runden
longitude: Math.round(lon * 1000000) / 1000000, // Auf 6 Nachkommastellen runden
altitude: alt,
hdop: hdopValue,
sats: satsCount,
accuracy: accuracyMeters
},
warnings: errors.length > 0 ? errors : undefined
};
}

its working:

"received_at": "2026-08-07T14:23:21.794469078Z",
"uplink_message": {
  "session_key_id": "AZ/dgsfdgsfdg==",
  "f_port": 1,
  "frm_payload": "sfsgsfdgsfdg==",
  "decoded_payload": {
    "accuracy": 37.5,
    "altitude": 152,
    "hdop": 7.5,
    "latitude": 4.275,
    "longitude": 5.47,
    "sats": 4
  },

How do you propose to implement this?

so there seems to be a bug in the ttn decoder.