Intern Rocket Project:
The objective of this project is to log flight data for a model rocket. The flight data includes temperature, pressure (altitude), acceleration, and GPS coordinates. There is an intelligent payload to gather and store the data, an RF link to transmit the data to a handheld unit, and compassing function to assist the handheld user in finding the rocket after landing.
Detailed Descriptions of each module:
- Real-time position tracking of a model rocket for easy recovery.
- Flight data logging for post-flight analysis.
- Learning about microcontrollers, communications, and electronics.
There were two devices that needed to be made, a hand held unit and a rocket board. Both needed a GPS and a wireless connection. The hand held would also have a LCD, compass, accelerometer, and SD card as well. The rocket board would have a barometer, thermometer, accelerometer, and DataFlash. A system block diagram is available here.
Here are the steps to logging a successful rocket flight with our system. This assumes you have all the necessary tools, experience, and supplies for launching a normal rocket capable of carrying the payload.
- Power up the handheld.
- Power up the payload and place in rocket.
- Press "Reset Rocket"
- Wait until the first four rows are populated with numbers indicating that both units have a valid GPS fix.
- When countdown begins, press "Ready to Launch"
- Track the rocket using the LCD display (N is north, Smiley Face is rocket, Square is you)
- When the flight is over, press "Receive Data" to download the data from the rocket to the handheld.
- To launch again, press "Reset Handheld" and repeat from Step 3.
- Blinking blue light on the handheld indicates communication link to payload. If it is solid on or off, communication has been lost.
- While it is convenient to have the rocket nearby when downloading (the handheld does not indicate download completion), it is not mandatory and data can be downloaded as long as the rocket is within communication range and operational. This is useful for data recovery if the rocket payload lands in an inaccessible location. A full read of DataFlash takes just under two minutes so wait two minutes after pressing "Receive Data" to be sure the rocket is done sending.
- The rocket payload software is not interrupt based so a very quick button press may not be registered; however, we did not have any trouble with button presses being too short.
Launch 1 (August 2, 2011)
Payload detached from parachute and quickly descended to earth; data was logged until impact. Estimated apogee of 650 feet above ground. Tracking system was buggy and pointed in the opposite direction of payload's location when 550 feet away. Wireless communication was fine; data was recovered before we located the payload.
Launch 2 (August 4, 2011)
Rocket stayed together. Data was logged and analyzed; estimated apogee of 500 feet above ground. Wireless communication worked flawlessly and position was tracked successfully from 850 ft.