🌈 A beautiful, eco-friendly weather station powered by E-Paper display! 🌱
⚠️ IMPORTANT: Please read the [Notes & Warnings] section carefully before proceeding with this project. It contains crucial safety information about battery configuration, charging, and sensor placement.
| 🎯 Tested On |
• Seeed Studio XIAO ESP32 C3 • Seeed Studio XIAO ESP32 C6 |
| 📟 Display | Waveshare 4.2inch TriColor 400x300 E-paper (15s refresh) |
| 🌡️ Sensors |
• TMP117 (Temperature) • BH1750 (Light sensing) • DS3231 (Time keeping) • BME680 (Humidity & pressure) |
| 🔋 Power | LFP 2x4000mAh (8000mAh total) Lithium Iron Phosphate Battery (IFR26700) |
| 🔌 Other | 2xBMS, capacitors, resistors, connectors, etc. |
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| 🌡️ Medical-grade Temperature | 💧 Humidity & Pressure | 🔋 Smart Battery | 🌍 Weather Data |
|---|---|---|---|
| ±0.1°C Precision | Real-time Monitoring | Intelligent Power Mgmt | Global Forecasting |
TMP117 Sensor |
BME680 Sensor |
2000+ Cycles |
OpenWeatherMap |
• 🌙 Moon Phase & Day/Night Tracking
• 🔄 Auto WiFi Configuration
• ⏰ Power-efficient Sleep Modes
• 📊 Environmental Monitoring
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Using SparkFun TPL5110 Timer + Power Management Board: 💡 How it worksThe TPL5110 completely cuts power to the system between updates, reducing standby current to near-zero levels. This improvement will dramatically extend battery life! |
📊 Performance Metrics
After recent code optimizations, power efficiency has significantly improved:
Mode Duration (Awake) Status Active-Active ~22s Sleep-Active-Sleep ~20s Sleep-to-Sleep <1s ✨ Key Improvements:
- CPU power thoroughly monitored and conserved
- Optimized mode transitions
- Minimal wake time in sleep cycles
📝 Note: Historical data below is from testing with Li-ion ICR batteries. The shorter duration in cycles 2 and 3 (49 and 48 days vs 73 days) was due to incomplete charging (batteries not reaching full 4.2V). New performance data with 8000mAh LFP batteries (which are more cost-effective) is being collected.
| Cycle | Duration | Details |
|---|---|---|
| First Cycle | 73 Days | 06/05/2024 - 17/07/2024 (2 months 12 days) |
| Second Cycle | 49 Days | ~7 weeks |
| Third Cycle | 48 Days | ~7 weeks |
| Cycle | Full Charge Date | Battery Dead Date | Duration |
|---|---|---|---|
| First Cycle | January 09, 2025 | Coming Soon | Ongoing |
Second: █████████████ 49 days
Third: █████████████ 48 days
⚠️ Note: Precise current consumption measurements for the entire project are not available due to equipment limitations. Please refer to the Battery Performance section above for real-world usage data and longevity estimates.
Clock Normal Mode |
Clock Power Conserved Mode |
Side View 1 |
Back View |
Side View 2 |
Top View |
ESP32 Compared |
Testing |
Integration |
Mainboard Front |
Internal 1 |
Internal 2 |
Facelift Clock |
LiFePO4 Cell 4000mAh |
Mainboard Back |
- 📱 E-Paper Display (no backlight needed)
- 🔋 LiFePO4 Batteries (Lithium Iron Phosphate)
- ✅ Cobalt-free chemistry, reducing environmental impact
- ✅ 2-3x longer lifespan than traditional Li-ion
- ✅ Non-toxic and more stable chemistry
- ✅ Better recyclability due to simpler composition
- 📦 Recycled cardboard construction
- 💡 Smart light sensor for power saving
🧠 Core System
- 💻 XIAO ESP32 C6 (Recommended)
- 32-bit RISC-V single-core CPU up to 160MHz
- 320KB SRAM, 4MB Flash
- WiFi 6 & Bluetooth 5.0
- Ultra-low power consumption: ~14µA in deep sleep (Source)
- Note: 14-15µA deep sleep current only achievable when power is supplied through battery pins (BAT+ and BAT-)
- 11 Digital/Analog pins
- USB-C interface
⚠️ May experience reduced WiFi range due to integrated PCB antenna- Consider ESP32 C3 variant with external antenna for better signal strength
- Signal strength highly dependent on enclosure material and placement
- ⚡ Deep Sleep Current:
- XIAO ESP32 C6: ~25µA total
- 14.3µA from ESP32C6 core (Source)
- ~11µA from all peripheral devices in standby (RTC, sensors, etc.)
- XIAO ESP32 C3: Higher deep sleep current (~43µA, tested)
- XIAO ESP32 S3: Potentially lower deep sleep current (~11.9µA, untested)
- Not used due to project's modest performance needs
- Could be viable alternative for maximum battery life
- XIAO ESP32 C6: ~25µA total
📡 Sensors & Connectivity
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🌡️ TMP117 High-Precision Temperature Sensor
- ±0.1°C (max) from -20°C to +50°C
- 16-bit resolution (0.0078°C)
- Low power: 3.5µA in shutdown mode
- Temperature range: -55°C to +150°C
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💨 Bosch BME680 Environmental Sensor
- Humidity: ±3% accuracy
- Pressure: ±0.6 hPa absolute accuracy
- Gas sensor for air quality
- Temperature range: -40°C to +85°C
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💡 BH1750 Light Sensor
- 1 - 65535 lux range
- 16-bit resolution
- Spectral responsivity close to human eye
- Low power: 120µA active mode
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⏰ DS3231 RTC Module
- Accuracy: ±2ppm (±0.432 sec/day)
- Temperature compensated crystal
- Battery backup support
- -40°C to +85°C operating range
⚡ Power System
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🔋 IFR26700 LiFePO4 Battery
- Nominal voltage: 3.2V
- Capacity: 4000mAh (8000mAh total with 2 cells)
- Cycle life: >1000 min. cycles
- Size: 26mm × 70mm
- Max discharge current: 8A
- Operating temperature: -20°C to +60°C
- Self-discharge rate: <3% monthly
- Battery critical threshold: 30%
- Higher threshold significantly increases battery lifecycle (Source)
- Urges to recharge at 30% remaining capacity
- Preserves cell health for longer service life
- Implemented in firmware via critBattPercent constant
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⚡ TP5000 Charging Module
- Input voltage: 4.5-8V
- Charging current: 1000mA (adjustable)
- Charging accuracy: ±1.5%
- LiFePO4 mode: 3.6V cutoff
- Over-voltage protection
- Temperature protection
- Short circuit protection
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📟 Waveshare 4.2" E-Paper Display
- Resolution: 400×300 pixels
- Three colors: Black, White, Red
- Active area: 84.8mm × 63.6mm
- Refresh time: 15 seconds
- Viewing angle: >170°
- Operating voltage: 3.3V
- Ultra-low power consumption
- No backlight needed
- SPI interface
📟 Display & Ghosting
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👻 Ghosting Issue: Even after using full scan/update mode, ghosting can occur
- Red lines may appear over black background
- Occurs when same elements stay static for extended periods
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🛡️ GhostProtek Mode
- Automatically inverts display colors periodically
- Activates after predetermined number of boots
- Prevents static elements from burning in
- Helps maintain display longevity
- Experimental feature to reduce ghosting artifacts
- 📱 Power on the device
- 🔄 Connect to
WCLOCK-WIFI-MANAGERWiFi network - 🌐 Navigate to the IP address shown on the display
- ⚙️ Enter your WiFi credentials
- 🎉 Device will restart and connect to your network
- 🔑 OpenWeatherMap API key required
- 🌍 Custom API support for personal weather station
- 📍 Configurable location (latitude/longitude)
- 🐛 Enable via DEBUG_PIN (D6)
- 📊 Shows network diagnostics
- 🔍 Displays detailed error messages
- 🔋 Battery voltage monitoring
- ⚡ Configurable sleep intervals (default: 15 mins)
- 🌙 Night mode with reduced updates
- 📉 Low battery failsafe mode
- Normal Mode
- Full weather data
- Temperature, humidity, pressure
- Moon phase and weather icons
- Sunrise/sunset times
- Limited Mode (Low Battery)
- Basic temperature display
- Battery status
- Time and date
- Night Mode
- Display sleeps when dark
- 5-minute wake intervals
- Power saving features
- 🔄 Current Update Method:
- No OTA (Over-The-Air) updates due to memory constraints
- Manual update process required:
- Turn OFF the clock using flip switch
- Press and HOLD the debug button (D6)
- While holding debug button, turn ON the clock
- It will disable sleep
- Release debug button when display starts to refresh
- Display will show temperature and then "DEBUG MODE" (No need to wait for this)
- Connect to PC via USB-C cable
- Upload new code using Arduino IDE
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Most DS3231 modules are sold with CR2032 or similar cells which are not rechargeable. If you are using a non-rechargeable cell then **REMOVE** either the resistor or the diode marked in the above image.
**IMPORTANT**: There are some misinformation over internet regarding the charging mode of TP5000. If you are using LiFePO4 cells with TP5000 then **DO NOT** short the above marked area with caption F.
- 🔋 Parallel Cell Configuration: While this project uses two LiFePO4 cells in parallel, this is generally not recommended with TP5000 or similar charging circuits
- Currently safe due to verified cell balance
- Long-term balance cannot be guaranteed
- Only implemented due to ultra-low current draw
- ⚡ Current Draw: This project's extremely low current consumption (well below rated cell capacity) makes the parallel configuration safer
- 🛡️ Protection: Always use proper BMS protection for your cells
- 📝 BMS Setup: Due to limited 1S LiFePO4 BMS availability:
- Using 4.2V BMS for 2.5V cutoff protection (Low Discharge Cutoff)
- TP5000 connected directly to cells for proper 3.6V charging
- This is a temporary solution until better 1S LFP BMS options become available
- ⚡ USB Connection Warning: Disconnect battery when connecting USB to ESP32C6
- XIAO modules are designed for LiPo/Li-ion batteries (4.2V charging)
- Not compatible with LFP battery charging (3.6V required)
- Dedicated USB-C module recommended
- Connect USB-C module output to TP5000 input
- Detailed schematics will be provided later
- Simple setup despite complex explanation
- ✅ Operating Range:
- All components work perfectly with LFP's lower voltage
- Tested operational down to 2.8V
- No impact on battery life or performance
- LFP cells maintain stable 3.2V for extended periods
- 6+ months of testing
- Components designed for wide voltage range operation
- 💨 Ventilation Requirements:
- Proper air vents are crucial
- Ensures accurate sensor readings
- Prevents heat buildup
- Essential for environmental monitoring
- 🔧 Sensor Orientation:
- TMP117 and BME680 must be mounted horizontally
- Sensors should face downward
- Prevents dust and particle accumulation
- Ensures accurate long-term readings
⚠️ Please consider these points carefully before replicating this setup. Battery safety is crucial!
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GNU General Public License v3.0
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