Christian Mueller
e706b22f31
Based on Pflichtenheft v2.2, documents the full system design including daemon, API, frontend, and infrastructure with agreed deviations (Axum 0.8, SQLx 0.8, Vite 6, Tailwind 4). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
147 lines
3.8 KiB
Markdown
147 lines
3.8 KiB
Markdown
# ChirpStack Decoder für Füllstandsmessung
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## Payload-Format (8 Bytes)
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Das Gerät sendet 8 Bytes via LoRaWAN:
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| Bytes | Beschreibung | Einheit | Berechnung |
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|-------|--------------|---------|------------|
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| 0-1 | Distanz | mm | Big Endian uint16 |
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| 2-3 | Füllhöhe | mm | Big Endian uint16 |
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| 4-5 | Füllstand | % × 10 | Big Endian uint16 (855 = 85.5%) |
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| 6-7 | Batterie | mV | Big Endian uint16 (3700 = 3.7V) |
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## Decoder-Code für ChirpStack v4
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```javascript
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function decodeUplink(input) {
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var bytes = input.bytes;
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var fPort = input.fPort;
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// Validierung
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if (bytes.length !== 8) {
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return {
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errors: ["Invalid payload length - expected 8 bytes, got " + bytes.length]
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};
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}
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if (fPort !== 1) {
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return {
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errors: ["Invalid fPort - expected 1, got " + fPort]
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};
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}
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// Distanz (Byte 0-1, Big Endian)
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var distanceMm = (bytes[0] << 8) | bytes[1];
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var distanceCm = distanceMm / 10.0;
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var distanceM = distanceMm / 1000.0;
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// Füllhöhe (Byte 2-3, Big Endian)
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var fillHeightMm = (bytes[2] << 8) | bytes[3];
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var fillHeightCm = fillHeightMm / 10.0;
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var fillHeightM = fillHeightMm / 1000.0;
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// Füllstand in % (Byte 4-5, Big Endian, × 10)
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var fillPercentRaw = (bytes[4] << 8) | bytes[5];
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var fillPercent = fillPercentRaw / 10.0;
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// Batteriespannung (Byte 6-7, Big Endian, in mV)
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var batteryMv = (bytes[6] << 8) | bytes[7];
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var batteryV = batteryMv / 1000.0;
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// Batterie-Prozent berechnen (LiPo: 3.0V = 0%, 4.2V = 100%)
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var batteryPercent = ((batteryV - 3.0) / (4.2 - 3.0)) * 100.0;
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if (batteryPercent < 0) batteryPercent = 0;
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if (batteryPercent > 100) batteryPercent = 100;
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return {
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data: {
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// Distanz (Sensor bis Flüssigkeit)
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distance_mm: distanceMm,
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distance_cm: distanceCm,
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distance_m: distanceM,
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// Füllhöhe (Flüssigkeitshöhe im Tank)
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fill_height_mm: fillHeightMm,
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fill_height_cm: fillHeightCm,
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fill_height_m: fillHeightM,
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// Füllstand in Prozent
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fill_percent: fillPercent,
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// Batterie
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battery_mv: batteryMv,
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battery_v: batteryV,
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battery_percent: Math.round(batteryPercent)
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}
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};
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}
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```
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## Beispiel-Payloads
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Angenommen: Tank-Höhe = 180 cm
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| Payload (Hex) | Distanz | Füllhöhe | Füllstand |
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|---------------|---------|----------|-----------|
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| `0348 0AA0 0226` | 84.0 cm | 170.0 cm | 94.4% |
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| `05DC 0708 0197` | 150.0 cm | 180.0 cm | 40.9% |
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| `0708 0000 0000` | 180.0 cm | 0.0 cm | 0% |
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| `0014 06F8 03E8` | 2.0 cm | 178.0 cm | 100.0% |
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### Berechnung Beispiel 1: `0348 0AA0 0226`
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- **Distanz**: `0x0348` = 840 mm = 84.0 cm
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- **Füllhöhe**: `0x0AA0` = 2720 mm = 272.0 cm (Fehler! sollte max 180cm sein)
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- **Füllstand**: `0x0226` = 550 = 55.0%
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## Installation
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1. Öffne ChirpStack → **Device Profile** → **Codec**
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2. Wähle **JavaScript** als Codec
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3. Kopiere den Decoder-Code ins **Uplink decoder** Feld
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4. Klicke **Submit**
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## Anzeige in ChirpStack
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Nach erfolgreicher Dekodierung siehst du in ChirpStack:
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```json
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{
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"distance_mm": 840,
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"distance_cm": 84.0,
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"distance_m": 0.084,
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"fill_height_mm": 960,
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"fill_height_cm": 96.0,
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"fill_height_m": 0.096,
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"fill_percent": 53.3,
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"battery_mv": 3850,
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"battery_v": 3.85,
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"battery_percent": 71
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}
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```
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## Grafana Dashboard
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Empfohlene Visualisierungen:
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1. **Gauge**: `fill_percent` (0-100%)
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2. **Graph**: `fill_height_cm` über Zeit
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3. **Gauge**: `battery_percent` (0-100%)
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4. **Graph**: `battery_v` über Zeit (Batterie-Entladung)
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5. **Graph**: `distance_cm` über Zeit (Fehlerdiagnose)
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## Troubleshooting
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### Negative Füllhöhe
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**Problem**: Füllhöhe zeigt negative Werte
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**Lösung**: Tank-Höhe (`TANK_HEIGHT`) im Code anpassen
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### Füllstand über 100%
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**Problem**: Füllstand zeigt über 100%
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**Lösung**: Sensor ist zu nah am Boden installiert oder Tank-Höhe falsch konfiguriert
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