BiosensorArray - Timestamp

Integration options

It would be good to write the Data Aggregator Board software (current target board is Arduino MEGA) so that it can use RTC, GPS or both. This would provide maximum flexibility to end user depending on their resources and environment.

Logic:

• POWER UP: If GPS module installed and good signal, then set time from GPS
  • If RTC installed too, then set time from GPS in case GPS signal degrades during operation
• POWER UP: If no GPS module installed or GPS bad signal, then
  • If RTC install & set, then get time from RTC
    • If no RTC installed, then:
      • Obtain timestamp from connected (USB or bluetooth) computing device (smartphone or PC)
      • If no computing device connected, then prompt for manual input (how?)

Time set by connected computing device

• Shawn mentioned that one simple method would be to set the time on the Arduino based on the serial link (bluetooth or USB) to computing device (smartphone or PC)

RTC

• Pro's:
  • Cheaper than GPS
  • Always works indoors since it doesn't need satellite signal

• Con's:
  • Requires initial time set
  • Not as accurate as GPS
  • Lacks GPS's inherit benefit of geolocation data

• Implementations:
  • DS1307-based Real Time Clock module (i2c)
  • RTC used in Heart Spark (i2c)

GPS

• Pro's:
  • Automatic time set
  • Adds geolocation data to biosignal data

• Con's:
  • More expensive than RTC
  • Requires satellite signal (potential poor indoor performance)

• Implementations:
  • Sparkfun GPS shield + module bundle
    • Available at Microcenter in Chicago, too
  • Adafruit shield
    • just a shield, requires seperate GPS module

Related

• Data Logging