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Arduino based GPS watch

Small GPS device is always nice to have. One thing is that it can be used to tell the time. But most importantly it is used give coordinates of your position and other derivative values like speed and distance. Oscar wanted to build small GPS watch which were small enough to carry around and have useful features like logging. Basically, GPS watch is based on Arduino Nano board which talks to Adafruit GPS module and Mini SD card module for logging. Information is also displayed on OLED mono color display. Watch is powered with single cell 600mAh LiPo battery. Charging module is also include in to box. Initial tests show that its accuracy is about 3meters and refresh rate is about 10Hz. Continue reading

Precise alarm clock uses GPS module

Arduino GPS clock

GPS satellites carry a precise clock sources. When receiver gets data from transmitters, there is time data packed along with position information. Time and date data can be parsed and used for any purpose. Kevin decided to make GPS driven alarm clock, that would set itself by reading GPS data. This way he wanted to skip usage of buttons. Recently he started initial test run of such system. He picked a 128×64 graphical LCD module where he drew nice big clock digits along with date and status information. He hooked up GPS module and graphical display to Arduino and run several successful tests. He was able to parse time and date data from GPS data packed and display on LCD. Next thing he had to include timezone adjustments since GPS displays time in GMT. Since there is enough room left on LCD, he also attached 1-wire DS18S20 temperature sensor that adds more value to the clock. It seems that there is no way to run away without user input here. In order to set alarm clock there is needed user… Continue reading

Very accurate clock using Arduino and GPS

You know that Global Positioning (GPS) wouldn’t be possible without accurate clocks. So each GPS satellite is equipped with very accurate atomic clock which absolute accuracy is ±1 second over 1 million years. Having such precision you wouldn’t have to adjust clock settings in all your lifetime. Practically if you have a GPS receiver you already have a accurate clock. Darius had and Arduino and Sirf II GPS module around and decided to make clock with time and date display. Originally GPS receiver communicates using RS232 interface. So in order to connect to Arduino there is a UART to RS232 level converter needed like MAX232. Sirf II GPS receiver sends data using NMEA protocol which is based on sending ASCII messages. To make things a bit interesting Darius also displays some additional information on LCD including number of satellites and GPS fix that indicates GPS module RTSS synchronization. Continue reading