Project Link : Digital Speedometer using GPS.

The project is very useful for GPS beginners. It uses data from GPS Module and maniupalte it for speed. GLCD is interfaced to controller using LPC2148 ARM7 using Serial Converter. A DC-DC Converter is also used for 3.3V to 5V conversion.

“There are four different products we have to connect to get this thing ready for programming: the Package Tracker, the Graphic LCD, the Serial Graphic Backpack, and the 5V Step-Up board. As should be obvious, the GPS module plugs directly into the Package Tracker and the microSD card also just gets inserted into the microSD socket on the board. Getting the LCD Backpack onto the LCD is as easy as soldering a female header onto one of the boards, and a male header onto the other, and plugging them in. After reading the LCD datasheet I found that I had to power the LCD with 5 volts. Unfortunately the Package Tracker is a 3.3V system, and is powered by a 3.7V LiPo battery. Luckily SparkFun has a 5V DC-DC converter breakout board! Now we just have to figure out how to get power from the Package Tracker to the 5V step-up, and how to get the 5 volts from the step-up board to the

LCD. The Package Tracker has a nice 6 pin header on one side that has VCC and GND. Maybe I can get power from this? Better check the schematic first though. Turns out we can’t use this VCC for the 5V step up board; the VCC on the header is from the 3.3V regulator on the Package Tracker. While 3.3V is enough for the step-up board we can only source 150 mA from this regulator. Considering the regulator has to power the LPC2148 plus all of the peripheral components on the Package Tracker I don’t want to risk adding another pretty big load to it by asking it to power the LCD and the Serial Backpack.

Since we can’t use the VCC on the header we’ll just have to take power directly from the battery to the 5V step-up board. I put the step-up board on a breadboard so that it was easier to work with, but you could probably figure out a way to get this working without it. Once we’ve got power to the breakout board, we’ll just connect the 5V output to the Serial Backpack and we’re good to go!” ……. read more

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Happy SpeedING =)