Google is taking Fitbit Air’s “replaceable Pebble body” design to the extreme, officially opening up the hardware specifications so that anyone can create their own accessories. This approach has a strong early Google style, which is open, experimental, and encourages the community to participate.
Google releases blueprint for Fitbit Air, opens up design and manufacturing of straps and accessories
After the launch of Fitbit Air last month, the community has begun to use their own creativity to produce a variety of alternative accessories, such as homemade upper arm straps. Google has noticed this craze and announced that it will fully disclose the hardware specifications and accessory design guidelines of Fitbit Air. It will no longer only be provided to third-party accessory manufacturers, but will be open to all “independent designers and handicraft creators.”
The content disclosed this time includes the main body of Fitbit Air (called pebble by Google) and the “sleeve” structure used by Performance Loop Band. 2D CAD drawings (PDF). These CAD files provide key structural dimensions, tolerance ranges, and force specifications required when the accessories are installed and disassembled, allowing anyone to create replacement accessories with stable quality and structural safety according to standards.
Google also listed in the official description several key points that developers must pay attention to when designing accessories:
- Sensor Clearance
The optical heart rate and SpO2 sensors on the bottom of Fitbit Air must remain completely unobstructed and maintain flat, stable contact with the skin. Google emphasizes that in order to ensure that users can still obtain accurate measurement results while exercising, the accessory design must maintain “gentle but steady” pressure in the sensing area. - Sensor Pressure
For optimal performance of PPG (light volume change) sensing in motion, Google recommends that accessories provide a continuous contact pressure of at least 35 mmHg (approximately 0.68 psi) in the sensing area. This is an important condition to ensure stable heart rate and blood oxygen measurements. - Secure Retention
The main body of Fitbit Air uses a “tension buckle mechanism” to be fixed in the accessory, so any shell or sleeve must comply with the CAD tolerances provided by Google to ensure that the main body remains firmly fixed during strenuous exercise and can be easily removed when replacing accessories.
In addition to structural design, Google also places special emphasis on the safety of accessory materials. The official document details material recommendations suitable for long-term skin use, and provides chemical substance restrictions, environmental standards and necessary testing requirements to avoid skin irritation or allergic reactions.
Google’s open strategy this time continues to some extent the company’s early spirit of “letting the community work together to build an ecosystem.” The modular design of Fitbit Air itself makes it more than just a fitness bracelet, but more like a wearable platform that can be used freely. By making the specifications public, Google allows more creators to participate, from professional accessory manufacturers to personal designers, to create more personalized and diverse accessory options for Fitbit Air.
Source: KOCPC Chinese