Thursday, February 14, 2008

GPS Success: Navigation Data Acquired

After fiddling a bit with the ETEK GPS Receiver, I finally got real data to come out! The datasheet included said the default baud rate was 4800 but it is infact 38400 baud. I assumed 4800 and the data being shown piped from the Arduino was all kinds of garbled nonsense. I decided to bypass the Arduino to see what was actually being sent from the GPS by loading a blank sketch (read: empty program which does nothing) onto the microcontroller. I popped up trusty old Hyper-terminal and started reading the nonsense. After setting the baud rate to 38400, the beautiful NMEA strings were happily populating my terminal window.

Next steps are to decode the stings and assign the outputs to readable variables. Anyone have a GPS output simulator?

Thursday, February 07, 2008

Progress Continues: Microcontroller and GPS Purchased




Arduino Diecimilia


Why?


  • Has a serial input

  • Multiple Analog input/output controls

  • Very cheap (~$30)

  • Familiar programming language

  • Large user help base



After buying this, I realzied I need a GPS first and foremost:




ETEK EB-85A


Why?


  • Cheap (~$55) seeing a pattern here?

  • 5 Hz refresh rate (say wah!?, most are 1Hz, or even 1/2Hz)

  • Serial NMEA output


Anyone know where I can get cheap, accurate pressure sensors?