GPS Logger Known as Delorme Tripmate

The purpose of the project is to create a serial data logger of GPS data that could record the position of the unit while allowing reading back the latitude and longitude after acquiring the data.

The original design of the GPS receiver uses an RS232 serial connection to send and receive data. It was modified to self-start, which automatically output position and satellite information when power is applied.

A cheap PIC16F88 microcontroller is used with a high speed internal oscillator with 8MHz frequency, an internal USART, and is boot loadable. The use of the microchip is for parsing the data, discarding any irrelevant information, and storing the variables of interest consisting of latitude and longitude.
The supply of power comes from a 4 AA NiMH batteries in series that would give a supply voltage of approximately 4.8V. The batteries can be recharged for Tripmate and for the logger and can last for quite a while. In cases when a 9V battery or alkaline batteries are used, a low dropout voltage regulator can be used to ensure that the IC will not burn out. The MAX232 is used for converting logic level signals.

Rest of the project