comments welcome: mrongen@halifax.rwth-aachen.de

• Still under development (T.B.D. = “to be done” or “to be determined”), no flight experience yet,…
• 4 AA Batteries, Latex Balloon
• 434.xxx Mhz, Shift xxx, xxx Baud
• Transmission every 30 second

• Five main modules clustered around central battery pack
• (mainly) I2C as communication protocol between modules

(System overview image)

• Distributes 6V from 4 AA batteries to all modules
• Mounted to back of standart battery pack
• Monitors battery voltage and total current via INA219 IC and 200mOhm shunt resistor
  • Datasheet: http://www.ti.com/lit/ds/symlink/ina219.pdf
• Design Files: (Link)

• Energizer Ultimate Lithium
  • Datasheet: http://data.energizer.com/PDFs/l91.pdf

• NavSpark Microcontroller (originalle an Indigogo Campaign)
• 100MHz 32bit LEON3 Sparc-V8
• Full GPS support with external battery
• 2x UART, 2x SPI, 1x I2C, ~80uA/MHz @ 3.3V
• P1PPS time reference with ± 10nsec accuracy
• Software: (Link)

(Photo)

• Integrated buck-converter power supply to 3.3V for itself and the uC
• Design Files: (Link)

IMU

• BMP180: Temperature, Pressure and humidity sensor
  • Datasheet: https://www.adafruit.com/datasheets/BST-BMP180-DS000-09.pdf
• LSM303D: 3 axis accelerometer und magnetometer
  • Datasheet: http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00057547.pdf
• L3GD20: 3 axis gyrometer
  • Datasheet: http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00036465.pdf

Telemetrie

• Radiometrix NTX2
  • Datasheet: www.radiometrix.com/files/additional/ntx2nrx2.pdf
• T.B.D.: Quarter wave antenna with solid or wire ground

Storage

• not all data can be transmitted, but everything is stored for offline analyses
• 1 GB micro SD-Card interfaced via SPI

(Photo)

• distributes I2C to OTP, RD and PDB modules
• UART to GSM module
• +3V3 to OTP and PDB
• Design files: (Link)

T.B.D.

• BMP85 on breakout board
  • Datasheet: https://www.sparkfun.com/datasheets/Components/General/BST-BMP085-DS000-05.pdf

• ElecFreak GSM Module
  • Datasheet: (Link)
• integrated LDO power supply
• only powered up after landing, so to conserve battery and as the RD is EMI sensitive
• sends SMS with position, altitude, speed (hopefully zero) every X minutes

• PMT (Photomultipler) with Scintillator:
  • + high sensitivity
  • + good energy resolution
  • - high voltage needed (~ 1kV)
  • - heavy
  • - suscaptible to temperature and magnetic field changes
  • - complex to setup

• SIPM (Silicon photomultiplier) with Scintillator
  • + high sensitivity
  • + good energy resolution
  • + lightweight
  • - high voltage needed (~80V)
  • - VERY sucaptible to temperature changes
  • - complex to setup

• Geiger Müller tube
  • + easy to setup
  • + lightweight
  • o average sensitivity
  • - high voltage needed (~500V)
  • - no energy information at all

• Solid state detector (Teviso RD3024)
  • + trivial to setup
  • + low voltage (~5V)
  • + “some” energy resolution through the pulse with
  • + lightweight
  • - low sensitivity
  • - EMI sensitive

• array of radiation soft PIN diodes
• integrated bias-, amplification-, comperator-, and output-shaping circuit
• ~6CPM/uSh/h, essentially stable from 3 - 6 V, -40 - 60 °C
• pulse width is supposed to be slightly correlated to particle energy (to be tested further)
• SMD package
• Teviso sponsored one unit, otherwise ~120€
  • Datasheet: http://www.teviso.com/file/pdf/RD3024_DataSpecification.pdf

• ATTiny85 triggers on rising and falling edges of RD3024 TTL pulse
  • pulse width resolution: 1us
  • accuracy test with 130 us function generator pulses: 130.2 +- 2.3 us digitised
• ATTiny acts as I2C slave against FCU

(Photo and plots)

• Integrates buck-converter power supply to 3.3V
• allows soldering a grounded aluminium EMI shield over the RD3024
• Design Files: (Link)

• FlyCamOne Eco V2 (Link)
• integrated power supply
• Video, Timed Pictures
• 720 x 480px @ 30 fps
• max. 8 GB Micro SD card
• 4-6 V input

• breakdown voltage of air is drastically reduced at low pressures (Paschen Law)
• can lead to elevated discharge rates even at voltages below sparking
• coat PCBs and plugged connectors with Plastik70

• T.B.D.: Test full electronics system with conformal coating for elevated discharge at Paschen minimum.

• T.B.D.: Battery temperature is not supposed to drop below -10°C when exposing powered payload to -50°C for 20 minutes

• T.B.D.: Test GPS reception and RD noise during 70cm and GSM transmissions

• Possibly a test chasing a commercial hot air ballon with the payload

• Should stay afloat on standing water for at least 10 minutes

T.B.D.

T.B.D.

T.B.D.

• Diamond MR-77S Mag Antenna
• Custom QFH antenna - T.B.D.

• FunCube Dongle (Link)
• DVB-T Dongle (Link)

• in Germany I need a Flugverkehrskontrollfreigabe (liftoff permission) from the Deutsche Flugsicherung (German airspace control)
• 2 weeks lead time
• this includes the need for a 1 day aviation insurance (~60€)