🧢 This compact add-on hat for the XIAO series packs a punch with multiple smart features:
🌡️ SHT40 temperature & humidity sensor – for precise environmental readings 💡 BH1750 ambient light sensor – to measure brightness levels ⏰ PCF8563 real-time clock – ensures accurate timekeeping 🔋 Voltage divider – lets you monitor battery voltage with ease
Feature
🧢 Tiny Footprint Fits snugly on all Seeed Studio XIAO boards! With a slim lithium-ion battery tucked between the dev board and its hat, this logger is perfect for space-constrained projects. 🧩🔋
⚡ Power Supply Enable Sensors are GPIO-powered, allowing near-zero power sleep mode when idle. The always-on RTC sips less than 1 µA, making it ideal for battery-powered data loggers. 🌙🔌
🔗 I2C Communication Easy to code using existing libraries, and supports adding more sensors on the same bus. 📚🛠️
⏱️ On-board RTC The PCF8563 chip keeps time reliably and includes a programmable interrupt for deep sleep wakeups—essential for long-term logging. 🕰️🌿
📏 Accurate Monitoring
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🌡️ SHT40 sensor: ±0.2°C temperature, ±1.8%RH humidity
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⏰ PCF8563 RTC: Only ~7 minutes drift per year vs. 10 hours from ESP32’s internal RTC
🔋 Battery Voltage Monitoring Track battery status safely via a pin-enabled voltage divider. Perfect for mobile and remote deployments. 📉🔍
🤝 A Community Design Scaled Up by Fusion Co-Create This awesome module was designed by Westlake University's Marcel . Through Fusion Co-Create , we helped scale his idea using our Prototype → Produce → Promote pipeline. Marcel earns a commission for every unit sold—win-win! 🎓💡📦
🛠️ Fully Open Source on GitHub Schematics , layout , Gerber files—all open! Marcel also maintains firmware, updates, and tech support via GitHub . We highly recommend following the repo to stay in the loop. 🧑💻🔧📂
Specification
| Size | 21 x 17.8 mm |
| Operating Temperature | -40°C to 85°C |
| Power Supply Range | 2.4V ~ 3.6V |
| Current consumption | ~ 500uA |
| Idle current consumption | ~ 0.25uA |
| Communication Interface | I2C ● SHT40 Temperature & Humidity Sensor ● BH1750 Ambient Light Sensor ● PCF8563 Real-Time Clock ADC ● Battery Voltage Read |
| SHT40 temperature & humidity sensor read time | ~ 2ms |
| BH1750 ambient light sensor read time | ~ 120ms |
| Compatible Hardware Platforms | |
| Battery | EEMB 3.7V Lithium Polymer Battery (500mAh) |
🔌 Compatibility with Seeed Studio XIAO Boards
🧪 Marcel has tested the Logger Hat with:
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✅ XIAO ESP32C3
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✅ XIAO ESP32C6
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✅ XIAO ESP32S3
📌 Other XIAO boards should also work based on pin configurations, but here’s the breakdown:
| 🧠 Board Model | 🔋 Battery Charging | 📊 Battery Monitoring | ⚠️ Notes |
|---|---|---|---|
| XIAO SAMD21 | ❌ Not supported | ❌ Not recommended | No battery charging support |
| XIAO RP2040 | ❌ Not supported | ❌ Not recommended | Same as above |
| XIAO RP2350 | ✅ Supported | ⚠️ Needs extra wiring | Manual setup required |
| XIAO ESP32C6 | ✅ Supported | ✅ Simple 2-pin header | Fully compatible |
| XIAO RA4M1 | ✅ Supported | ⚠️ Needs extra wiring | Manual setup required |
| XIAO MG24 | ✅ Supported | ⚠️ Needs extra wiring | Manual setup required |
| XIAO nRF52840 | ✅ Supported | ✅ Simple 2-pin header | Fully compatible |
| XIAO ESP32C3 | ✅ Supported | ✅ Simple 2-pin header | Fully compatible |
| XIAO ESP32S3 | ✅ Supported | ✅ Simple 2-pin header | Fully compatible |
🛠️ For boards that require extra wiring, make sure to consult the schematics before enabling battery monitoring.
| XIAO Board s | I2C | INT | ADC | EN | BAT |
| XIAO SAMD21 | yes | yes | yes | yes | no |
| XIAO nRF52840 (Sense) | yes | yes | yes | yes | yes |
| XIAO RP2040 | yes | yes | yes | yes | no |
| XIAO RP2350 | yes | yes | yes | yes | yes but not aligned |
| XIAO ESP32C3 | yes | yes | yes | yes | yes |
| XIAO ESP32S3 (Sense) | yes | yes | yes | yes | yes |
| XIAO ESP32C6 | yes | yes | yes | yes | yes but not aligned |
| XIAO RA4M1 | yes | yes | yes | yes | yes but not aligned |
| XIAO MG24 (Sense) | yes | yes | yes | yes | yes but not aligned |
Hardware Overview
Application
🌡️ Real-Time Environmental Monitoring Track temperature and humidity with precision—perfect for smart sensing projects.
🏠 Connected Home Automation Node Integrate into your smart home setup for responsive, data-driven control.
🔋 Low-Power Data Logger Ideal for long-term deployments with minimal energy usage.
🧢 Wearable Tech Projects Compact enough for wearables—log environmental data on the go.
👩💻 Education in Programming & Monitoring Great for learning I2C, sensor integration, and low-power design in classrooms or maker labs.
Part List
| XIAO Logger Hat board | x1 |
| 7-pin female header | x2 |
Note: Li-ion battery not included