I have an Arduino Mega 2560, a gps module (NEO-6M-0-001) and an Adafruit 10-DOF board.
I am building a location tracker with IMU so that the GPS logs location and when it signal drops out, the IMU will then calculate the position from acc, gyro, compass. Just a project atm, but will probably add sd/phone board for logging or SMS locating so I can use it for my car or maybe even on the dog.
Anyway for my code, I am sampling the acceleration at 100 Hz and processing, then by addition, giving the final location. This is where my query comes.
I have heard the Arduino clock is not very accurate at all, therefore the location accuracy would drift massively.
So I have 2 options: Use a real time clock (RTC) like the ChronoDot which uses the DS3231. This looks perfect for accuracy (1 minute per year drift). Use the GPS clock, which would be good because it saves on components. However without an external time signal, I do not know how accurate its internal clock actually is. I've had a quick look at the datasheet but I'm not sure what I'm looking for.
So does anyone know how accurate the Arduino and GPS internal clocks are compared to the ChronoDot?