I was looking for a system that logged me during my hiking or biking, i just find Arduino, and build this small nice homebrew project below!
So, the Requirement are:
– Light and Small.
– Be portable.
– Be rechargeable easily.
– Large battery autonomy.
– Very sensitive.
The mainboard is build around Atmega328 (µp from arduino uno) a small GPS module (EM 406) give NMEA $GPGGA sentence to the µP via TX/RX port (PD1PD0)
(Tracking Sensitivity: -159 dBm) when a valid position is obtained, he write them to the microSD card, through arduino-micro-sd module.
We need to wait around 30 sec/1 min to get valid signal from the satellite.
The power consumption of GPS is around 45mA – Protocol baud rate 4800 bps/TTL
Powering is build around a charge pump powered via a Li-Ion/Li-Polymer batterie cell-phone (Nokia BP-4L 1500ma/3.7v)
The batterie charger is powered via MAX1811, we can use USB connection from computer, or external supply.
The total consumption is around 120ma full writing data, for a weight of 75g, and 72x45mm dimentions.
The code was created under Arduino environement, (thx to raulhc), is an open-source electronics prototyping platform, so you can modify the source like you want.