Electrical hardware of data acquisition and control system of Identity-II rocket

1. Data Acquisition
   • Altitude measurement via BMP280
   • 3-Axis Accelerometer, 3-Axis Gyroscope, 3-Axis Magnetometer reads data in every cycle
   • System time is recorded with the data
   • All the data measurements are taken in every 5-7 ms
   • Raspberry Pi camera module saves the recorded image automatically after the power is on
2. Communication
   • Zigbee communication is tested to reach 1000m without severe interference
   • Baud rate of 38400 is used for serial communication with the XBee module; At higher rate, some Arduino chips are not able to handle the speed of the signal alternation
   • Rocket status code along with the current altitude and time is sent via Zigbee channel
3. Control
   • Drogue parachute ejection at the peak altitude; Simple peak detection
   • Main parachute ejection in two modes
     1. Relative altitude mode (Max. Alt. < 390m): Main parachute ejection at "alt. = max. alt. - 70m"
     2. Absolute altitude mode (Max. Alt. > 390m): Main parachute ejection at "alt. = 320m"
4. Others
   • Additional 6 analog pins of Arduino Micro core can be reachable at the back of the core module

• Li-Po battery 3.7V, minimum 2000 mAh (x3)
• Buck converter 5V output, minimum 2A (x1)
• Arduino Micro (x1)
• Digi XBee-Pro (x1)
• MicroSD card adapter (x1) (You may use other boards)
• GY-91 IMU sensor (x1)
• L293B (x1)
• Raspberry Pi 3 or high (x1)
• PiCamera for RPi (x1)
• Power switch (x1)
• Some terminal blocks
• Some hexagonal supporters, 3-phi

• Arduino source code ()
• Data decoder code ()

There are three PCB layers with additional battery mount assembled in the following order:
(top)
battery
power module
core module
imu module
RPi Camera and Power button mount
RPi

Jaerin Lee
Lead Electronics and Software Developer
SNU Rocket Team Hanaro

Documented with KiCAD version 5.0.0