AED
R-DAS (Rocket Data Acquisition System)
The R-DAS is undoutedly the Rolls Royce of rocketry avionics systems. Available in 2 sizes with almost identical functionality;
This system is used for measuring and storing analog and digital data gathered during the rocket flight. Furthermore it can be used to set off your pilot and main parachute charges. The whole system is built on a very compact double-sided printed circuit board. Small enough to fit in almost any high-power or amateur rocket.
Because of its versatility, use of the R-DAS unit is not limited to in-flight data-acquisition. By using the switch (breaking wire) arming it can e.g. be used for data-acquisition of your thrust-bench setup.
The R-DAS has some features not offered by many of the known flight computers:
Not so much an altimeter/accelerometer as a full flight computer, the R-DAS comes with a barometric pressure snsor, accelerometer, 6 analogue input channels, 4 digital input channels, an expansion port and 2 analogue outputs (for recovery system deployment).
| R-DAS Specifications. |
| Acceleration transducer -50..+50 g, 0.1 g resolution (using the newest accelerometer of Analog Devices, the ADXL150) |
| Pressure transducer 20..105 kPa, 0.09 kPa resolution (Motorola MPXS4100) |
| 6 user available analog input channels, 0..5V, 10 bit |
| Maximum sampling rates of 8 above channels is 200 samples/second per channel |
| 4 user available digital input channels |
2 output stages for pilot and main parachute deployment
|
| G-switch and/or breaking-wire arming (selectable make or break contact) |
| Loud beeper for status indication |
| 512 Kbytes FLASH EEPROM (mapped as: write protected 64 Kbytes boot code, 64 Kbytes program code and 384 Kbytes nonvolatile data storage) |
| 32 Kbytes RAM memory |
| Reliable professional 2-layer PCB |
| RS-232 output |
| Runs on a single 9V battery (any power supply between 9 and 15 V will do) |
| Separate power supply for analog and digital circuits |
| Sealed, gold plated, ON/OFF switch |
| For the Classic R-DAS, there is a choice of a 9V battery holder on back of PCB (can be left off to reduce unit size, please specify when ordering, see figure below) |
- Easy to configure: Configure the R-DAS system with easy-to-use Windows 95/98/ME/2000/NT software or via a PDA with Windows CE or a Palmpilot: G-switch and/or breaking wire arming, smart recovery (integrating accelerometer, barometric main parachute) and/or timed recovery, barometric altitude for main chute release, extra data-acquisition channels, sampling rate, etc.
- Huge amount of data storage: e.g. ambient pressure and acceleration are sampled 200 times per second for more than 8 minutes. At lower sampling rates the sampling time is proportionally longer.
- Pre-flight data: the large RAM memory of R-DAS is continuously updated with the last 2 seconds of pre-flight data. After lift-off the unit starts storing the data in EEPROM, starting with the last 2 seconds before lift-off. In this way also pre-flight data is available, e.g. for offset calibration, or drift verification!
- Extra analog inputs: 6 analog input channels are available through a 16-pin boxed header for own experiments. This connector also provides your experimental board with a 9V power supply.
- 4 digital inputs: read and store the status from up to 4 digital inputs.
- Program code is upgradable: simply download future versions of the program code from the web, and upgrade your R-DAS system in minutes.
- Multiple rocket flights: Separate EEPROM's with boot code are available (Classic R-DAS Only). This makes it possible to fly several rockets with the same R-DAS without the need to download the data immediately after each flight. Of course, each EEPROM may contain a different configuration!
- I2C bus: The I/O connector features a serial I2C-bus. This allows simple extension of the R-DAS with e.g. LCD-screens, igniter output boards, remote data-acquisition boards, telemetry boards, IR boards or GPS boards.
Currently, the following expansion modules are available for both models of the R-DAS:
- Igniter Board
- This expansion module provides an additional 2 output channels
- GPS Board
- This expansion module provides an integrated GPS module with an additional remote GPS antenna, which can provide a 3-dimensional plot of the rocket trajectory.
- Telemetry Board
- The telemetry module provides both the transmitter module that connects to the R-DAS, and a receiver unit that plugs into a laptop or a PDA equipped with the R-DAS software. It allows real time telemetry to be received from the rocket, and, when combined with the GPS unit, it also enables real time position data to be received.
- X-Y Acceleration and Temperature Board
- The X-Y acceleration board allows all 3 axis of acceleration of the rocket to be measured (in conjunction with the Z-axis of acceleration on the R-DAS), as well as temperature.
The photograph to the left shows one of the R-DAS expansion modules; in this case, an additional igniter board. The 2 mounting connectors on the left enable output channels to be wired in. The rainbow ribbon cable to the right, connects to the R-DAS expansion port.
