Basic functionality

This code works on our mostly-off-the-shelf prototype.

Features

• Reads 3 temperatures in Fahrenheit to nearest 0.15 degrees
• Gets time and location from GPS
• Logs time and date in ISO8601 format
• Transmits wirelessly via XBee every 2 seconds
• Logs data to SD card every 2 seconds
• Runs off battery

Sample data log

2015-08-18T17:51:50Z | 4222.91N | 7106.32W |  88.70 |  87.80 |  88.70
2015-08-18T17:51:52Z | 4222.91N | 7106.32W |  88.70 |  87.80 |  89.15
2015-08-18T17:51:54Z | 4222.91N | 7106.32W |  89.15 |  87.80 |  89.15
2015-08-18T17:51:56Z | 4222.91N | 7106.32W |  89.15 |  87.80 |  89.15
2015-08-18T17:51:58Z | 4222.91N | 7106.32W |  89.15 |  88.25 |  89.15
2015-08-18T17:52:00Z | 4222.91N | 7106.32W |  89.15 |  88.25 |  89.60
2015-08-18T17:52:10Z | 4222.91N | 7106.33W |  88.70 |  88.25 |  89.15

Known weaknesses

• GPS slow to get fix when XBee is running, but we haven't added any antennas yet