This project contains stuff, which can be useful to program an Adruino MEGA with glider applications.

Why Arduino?
Because it offers high level uC programming in C++ and has lots of libs already available.

Why Arduino Mega?
Because I still had one in my bottom drawer. http://arduino.cc/en/Main/ArduinoBoardMega1280

Project aim:
Connect different sensors to the Arduino and do in flight measurement and data processing in a glider. The measured data will be stored on a microSD card shield.

Sensors:
- Temperature und Humidity sensor (HYT)
http://www.ist-ag.ch/eh/ist-ag/resource.nsf/imgref/Download_EN_HYT271_201109.pdf/$FILE/EN_HYT271_201109.pdf
This sensor is connected to the Arduino via I2C (SDA=Pin 20, SCL=Pin21). It is powered with +5V by the Arduino (PWR=5V, GND=GND).

- Flarm
Flarm outputs NMEA signals. These signals are based on a 12V TTL signal, which has to be shifted to 5V TTL signal. I am using following level shifter http://www.sparkfun.com/products/449 to convert the signal for Arduino input. The level shifter can be powered by the Flarm +3V line.
See chapter 8 of the Flarm installation manual (http://www.flarm.com/support/manual/FLARM_InstallationManual_v5.00E.pdf) for details about the Flarm wiring and which wires provide TX/RX signals.
The shifted Flarm signal is by the Arduino via UART on TX1/Pin 18 and RX1/Pin19

Flarm sends following NMEA sentences:
PFLAU, GPRMC, GPGGA and PGRMZ

Further details about these statements can be found under:
http://www.flarm.com/support/manual/FLARM_DataportManual_v5.00E.pdf

- Pressure sensors
I ordered two barometric pressure sensors (http://www.sparkfun.com/products/9694). Still waiting to get them. I plan to make dynamic and static pressure available to the Arduino with these breakouts via I2C.


- SD card shield
I am using an SD card shield (http://www.sparkfun.com/products/9802) to store measured information in a file on a SD card.
Unfortunately, the SPI communication wires to the SD card shield have to be rerouted to work with the Arduino Mega board:
On the shield cut pins 10-13 off. Then establish following wiring:
SD shield --> Arduino Pin
10 --> 53
11 --> 51
12 --> 50
13 --> 52 
Reason for this is, that the SPI communication pins are in different locations on different Arduino boards.


Data processing:
All data is processed and written to a terminal (serial) and on the SD card. The data is stores in a file called DATALOG.TXT.
Here is one example line of the file: Time UTC, Lat., Long., GPS Alt in m, Pressure alt in ft., rel. humidity, Temp in C 
175828 48.742138 11.445361  364  1192  65.36 22.29 

The file is automatically appended with new entries.

Based on this data I want to do some statistical analysis about temperature and humidity distributions within thermals.

Unless otherwise stated I license all information contained in this project under the GPLv3 (http://www.gnu.org/licenses/gpl-3.0.html). The NMEA lib has a different flavor of license.