leehughesandClaude Opus 4.5
265a53768e
- PlatformIO project for Meshnology ESP32 LoRa V3 - DS18B20 dual sensor support for tank verification - OLED display for local temperature visibility - HTTP POST to ZNET Web API - WiFiManager for easy WiFi configuration - Offline buffering when network unavailable Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
154 lines
4.0 KiB
Markdown
154 lines
4.0 KiB
Markdown
# ZNET Temperature Sensor - ESP32 LoRa Gateway
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## Project Overview
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ESP32-based temperature monitoring system for e-coat paint tanks. Reads DS18B20 waterproof temperature probes immersed in the paint tank and sends data to ZNET Web for real-time monitoring and ML feature collection.
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## Hardware
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| Component | Model | Purpose |
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|-----------|-------|---------|
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| MCU | Meshnology ESP32 LoRa V3 | Main controller with WiFi, LoRa, OLED |
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| Temp Sensor | DS18B20 (x2) | Waterproof stainless steel probes in paint tank |
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| Display | Built-in 0.96" OLED | Local temperature display for operators |
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| Radio | Built-in SX1262 | LoRa 915MHz for future remote sensors |
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## Quick Start
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### Build & Upload
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```bash
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# Install PlatformIO CLI
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pip install platformio
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# Build
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cd ~/Nextcloud/Dev/znet-temp-sensor
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pio run
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# Upload to ESP32 (connect via USB)
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pio run --target upload
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# Monitor serial output
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pio device monitor
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```
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### Configure WiFi
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1. Power on the ESP32
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2. Connect to WiFi network: `ZNET-TempSensor` (password: `znettemp123`)
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3. Browser opens captive portal - enter your WiFi credentials
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4. Device connects and starts posting to ZNET Web
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### Configure API Endpoint
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Edit `include/config.h`:
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```cpp
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#define ZNET_API_URL "http://192.168.1.100:8000/api/v1/sensors/readings"
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```
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## Wiring
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### DS18B20 Connection (1-Wire bus, both sensors on same pin)
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```
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ESP32 GPIO7 ─────┬───────────── DS18B20 #1 DATA (yellow)
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│
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└───────────── DS18B20 #2 DATA (yellow)
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ESP32 3.3V ──────┬───────────── DS18B20 #1 VCC (red)
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│
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└───────────── DS18B20 #2 VCC (red)
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ESP32 GND ───────┬───────────── DS18B20 #1 GND (black)
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│
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└───────────── DS18B20 #2 GND (black)
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4.7kΩ pullup resistor between DATA and VCC
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```
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### GPIO Pinout (Heltec V3 / Meshnology)
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| Function | GPIO |
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|----------|------|
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| OneWire Data | 7 |
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| OLED SDA | 17 |
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| OLED SCL | 18 |
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| OLED RST | 21 |
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| LoRa SCK | 9 |
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| LoRa MISO | 11 |
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| LoRa MOSI | 10 |
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| LoRa SS | 8 |
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| LoRa RST | 12 |
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| LoRa DIO1 | 14 |
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| LoRa BUSY | 13 |
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## Configuration
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All configuration in `include/config.h`:
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| Setting | Default | Description |
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|---------|---------|-------------|
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| `ZNET_API_URL` | - | ZNET Web API endpoint |
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| `DEVICE_ID` | `tank_gateway_1` | Unique device identifier |
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| `TEMP_READ_INTERVAL_MS` | 30000 | Reading interval (30 sec) |
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| `TEMP_MIN_VALID_F` | 32.0 | Minimum valid temperature |
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| `TEMP_MAX_VALID_F` | 150.0 | Maximum valid temperature |
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## API Integration
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### POST /api/v1/sensors/readings
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```json
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{
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"device_id": "tank_gateway_1",
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"device_name": "E-Coat Tank Gateway",
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"readings": [
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{
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"sensor_id": "tank_primary",
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"temperature_f": 85.5,
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"is_valid": true
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},
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{
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"sensor_id": "tank_secondary",
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"temperature_f": 85.3,
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"is_valid": true
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}
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]
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}
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```
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### Response
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```json
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{
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"success": true,
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"readings_stored": 2,
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"alerts_generated": 0
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}
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```
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## Features
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### Implemented
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- [x] Dual DS18B20 sensor reading with validation
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- [x] OLED display showing current temperature
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- [x] WiFiManager for easy WiFi setup
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- [x] HTTP POST to ZNET Web API
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- [x] Offline buffering when network unavailable
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- [x] Automatic sensor discovery (1-Wire)
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### Future (Phase 3)
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- [ ] LoRa receive for remote sensor nodes
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- [ ] Battery-powered remote node firmware
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- [ ] Sensor agreement monitoring
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- [ ] Flash storage for offline buffer persistence
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## Related Projects
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- **ZNET Web**: `~/Nextcloud/Dev/znet-web` - Backend receives temperature data
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- **Baserow**: Table for lab temperature logs (to be created)
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## Git Repository
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- **Remote:** https://git.ecoat.us/leehughes/znet-temp-sensor.git
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- **Main branch:** `main`
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## Change Log
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| Date | Version | Change |
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|------|---------|--------|
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| 2026-01-24 | 1.0.0 | Initial implementation |
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