• Tiny footprint: Fits neatly on all Seeed Studio XIAO microcontroller boards. With a small lithium-ion battery sandwiched between the dev board and its hat, the logger is well fitting for space limited projects.
• Power supply enable: The GPIO-powered sensors allow almost a no-power sleep mode when the sensors are not used. The always-on RTC consumes less than 1 uA making it suitable for battery-powered data loggers.
• I2C communication: Easy to program from existing libraries and supports adding more sensors on the same bus possible.
• On-board RTC: The PCF8563 chip with its oscillator provides timekeeping, essential for long-term data loggers, and a programmable interrupt for deep sleep wakeups.
• Accurate Monitoring: The SHT40 temperature sensor presents temperature readings with 0.2°C accuracy and humidity with 1.8%RH. The PCF8563 real-time clock has shown a 7 minute time shift over one year compared to 10 hours from the ESP32’s internal RTC.
• Battery Voltage Monitoring: When connected with the lithium-ion battery, its status level can be safely monitored through a pin-enabled voltage divider.

A Community Design Scaled up by Fusion Co-Create

This cool creation is designed by Westlake University’s Marcel. We’re excited to work with him to bring this impactful design to the market via our Fusion Co-Create. It’s a program where we applied the Fusion Prototype, Produce, and Promote services to scale up cool community projects, while the designers get a commission for each single piece sold.

Fully Open Source on GitHub

This product is fully open-sourced with schematics, layout, and Gerber files on GitHub, and Marcel will maintain all the firmware, software updates, and tech support over there too. We highly recommend you to follow the GitHub repo to stay updated.

[Github Repo]

Compatibility with Seeed Studio XIAO

While Marcel has only tested the Seeed Studio XIAO ESP32C3, ESP32C6, and ESP32S3 boards (by now) with the XIAO Logger Hat, other XIAO boards should also work based on the pin configurations. XIAO SAMD21 and RP2040 don’t support battery charging and should not use battery monitoring. XIAO RP2350, ESP32C6, RA4M1, and MG24 support battery charging but need additional wiring. XIAO nRF52840, ESP32C3, and ESP32S3 fully support battery monitoring with a simple 2-pin header connection.

• Real-time temperature and humidity monitoring
• Connected home automation node
• Low-power environmental data logger
• Wearable devices
• Programming and monitoring education

Note: Li-ion battery not included