Let me first give you some background information on what I am
attempting to do. I am using the PC104 board serial ports to... read in GPS position coordinates from a GPS on one serial port, read in measurements from a temperature sensor on another serial port, take these two data strings and combine them, and then via another serial send them to an amateur radio modem for transmission. I am using C for the coding. Now as I said before I can get COM3 (temp sensor) and COM4 (GPS) to read in correctly however when I attempt to use COM1 or COM2 nothing happens. I would also like to add that my temp sensor is powered by the serial port and when it is connected to COM3 or COM4 the power LED illuminates (thus showing that at least something is happening). I have noticed that the difference between the serial ports on my PC and on the PC104 is that on the PC104 when I connect my temp sensor the led light automatically comes on without running my code. However, on my PC, the power light is off until my code is executed. When my code finishes the light goes back off. This ofcourse is not the case with the PC104 board. The power LED is ON constantly when the temp sensor is pluged into COM3 and COM4 and always off when I connect it to COM1 and COM2 (thus showing it is receiving no power. I have tried to connect COM2 to my PC and transmit some characters however this does not work, nor does the receive. If some could lend me some aid it would be most helpful. Thanks