I have a device connected to the Serial Port and i wish to extract it's readings into a C Program. I have written a program to read and display the Serial Port Output but it gives out Garbage. Is there a need to process the output before displayin in order to get the required values in Hex? If so, how do i go about it? Thanks for your help in advance.

There are numerous reasons why the serial port might be giving you garbage. Do you have the baud rate set correctly, are the stop bits and parity bits correct. How are you accessing the serial port, polling or interrupts. The serial port reads pure binary numbers. If you are expecting Hex you are going to have to convert binary into Hex. Stuart

Continuing from your previous post. What is the device that you are trying to read? It must have some documentation of the communications protocol and data format. Most serial ports are designed to transfer whole words (normally 8 bit, but other values are possible). As previously mentioned you will have to convert your input to get HEX. It would be easier to debug with a known working terminal program. There are some that have a diagnostic mode that displays the raw data stream. Note that some devices have non-standard protocols (Especiallly those running at low baud rates). Make sure hardware handshaking is correct if used. It's easier to test if your device can be set to continually output. Then vary your terminal settings until you get decipherable output.

I'm working with an Inertial Measurement Unit (RS232 Interface). All i've done so far is an open followed by a read on the serial port. Here's a sample output: Read Status is 100 @Ð !!!!¬þ 1!!¬¥ü !%!±ü !!'±ü !!'±ü !!!±ü !%±ü !%'¬þ Read Status is 55 '±ü !!%±ü !±ü !% ±ü !!'; ±ü !!!±ü !%±ü !%'¬þ Read Status is 21 @Ð !!%±ü %54 !±ü !% ±ü !!'; ±ü !!!±ü !%±ü !%'¬þ If possible, could anyone send me an example of wat i shud ideally be looking for or an example of how to read the serial port using C Programming? Sorry about the trouble and thanks a lot for your patience and help.

If you were to look at the numbers and not their ASCII equivalent then it might make a little more sense. What you have is like looking at a programme file with a text editor - is doesn't mean much. In amongst the data are some characters that are outside the normal ASCII range so it is not ASCII that is being transmitted. There is a lot of repetition there which if you could establish a pattern will give you some idea of what is happening. Stuart

The repition is acceptable because the INS is stationary. So i presume those symbols correspond to the output of the INS wen it is stable. If i were to move it about, then the readings would change. I still cant find a way to interpret those readings. If i just execute a read on the serial port, should it not be giving out values in binary unless there is a prob with the serial port itself, which there doesnt seem to be! I cant find a solution to this anywhere on the web or in a book. Please Help!

It is giving readings in binary. As wizard-fred pointed out, you should have/get the documentation telling you the format of each frame/string the device spits out. Otherwise you'll have to guess or deduce it from experiment.