The Featherweight Blue Jay Altimeter is a compact and feature-rich dual-deployment altimeter designed for amateur rocketry. It offers advanced capabilities at an entry-level price point of $80, making it an attractive option for both beginners and experienced rocketeers.

Key Features

Size and Installation
- Dimensions: 1.45" long x 0.65" wide
- Easy installation with 2 screw terminals per e-match
- Built-in magnetic switch for simple activation

Connectivity and Interface
- Bluetooth connectivity to the Featherweight UI phone app (iOS and Android)
- Real-time sensor health and continuity voltage monitoring
- Immediate flight summary download post-landing

Sensors and Data Logging
- Barometric pressure altitude sensor (10-1200 mbar range)
- 3-axis high-resolution accelerometer (+/- 32 Gs)
- 3-axis gyro tilt sensors
- Data recording at 50 samples/second

Deployment Capabilities
- Dual-deployment with 2 pyro channels
- Apogee ejection option
- Descending altitude ejection option
- Timer ejection option
- Configurable velocity ejection option

Flight Data Recording
- Peak altitude and speed
- Peak and average acceleration
- Booster burn time
- Coast to apogee time
- Apogee to ejection time
- Ejection altitudes and times
- Flight duration

Advanced Features

Multi-Sensor Apogee Detection
The Blue Jay employs fault-tolerant apogee detection using multiple sensors, ensuring accurate deployment even in flights exceeding 32 Gs during boost.

Inertial Navigation
Incorporates gyro-based tilt calculation and inertial navigation for comprehensive flight analysis.

Ground Testing
The app includes a ground test feature for charge testing, recording video and on-board data.

Flight Simulation
Offers a sophisticated flight simulation tool for pre-flight verification of deployment settings.

Performance and Limitations

• Power consumption: 15mA
• Input power compatibility: 3V-12V
• Suitable for e-matches but not igniters due to limited power hold-up time (15 msec)
• Barometric sensor tested up to 75,000 feet, with reliable performance confirmed up to 35,000 feet

Comparison to Blue Raven

The Blue Jay offers most of the Blue Raven's capabilities at less than half the price, with some trade-offs:

• Reduced flash memory and lower sampling rate (50 samples/second)
• Lower maximum accelerometer range (+/- 32 Gs vs 400 Gs)
• Lacks large hold-up supercapacitor for extended power loss protection
• Smaller, less expensive barometric sensor

What's Included

• Featherweight Blue Jay Altimeter Unit
• Mounting hardware (nuts, bolts)

What's NOT Included

• Batteries/chargers for powering the altimeter
• Smartphone (required for app functionality)
• Battery charger
• Magnet for switch activation
• E-matches
• User guide (available online)

What's Not Needed

• Cellular service at launch site
• Directional antenna

The Featherweight Blue Jay Altimeter combines ease of use, advanced features, and affordability, making it an excellent choice for rocketeers seeking a capable dual-deployment solution.