Post by thread:[PIC]: Would anyone understand...?]]

Jose S. Samonte Jr. wrote: > > No sir Vasile. > My life wouldn't go on if I'm not able to do this project. > I would fail my studies if I'm not able to do this. Then > I wouldn't be able to study for a year because my parents wouldn't > be able to send me anymore to school, that's why I really want to graduate, so > I would be able to work, and help my parents. > > I hope that anyone would still understand me... We understand you Jose. :o) But paying someone to do your work is not good. If you can't do the work you should not get the degree. That is not fair to the rest of the people who worked hard for their degrees. It is like paying your teacher to pass you, even if you can't do the work. OK, we would all like you to pass. What you could do is work hard on the parts of your project that you can do. Like the LCD interface, etc. If you do a good job on these parts, and it shows the teacher that you have learned a lot and worked hard, you should still pass the subject with the good parts even though the RF part does not work. The teacher needs to see that you learned the stuff, that's more important than if the thing works. :o) -Roman -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spam_OUTlistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

> My problems are on the preamble, sync word, and the checksum/ > CRC. Basically, it's packet transmission and reception. OK, that's a start. Whatever the format, they are still just bits and byes with some simple maths I'm sure that some, if not all, of the answers you need are on this page. You didn't say which PIC you are using, but there is some- thing for most of them http://www.piclist.com/techref/microchip/rs232.htm Take some time, download the lot and read them. It won't hurt to have more information than you need You may want to try this as your transmitter http://www.piclist.com/techref/microchip/rftxcw.htm -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body

> My problems are on the preamble, sync word, and the checksum/ > CRC. Basically, it's packet transmission and reception. Preamble's are just a long string of 1's and 0's to indicate transmission is about to start. Sync words are just a collecting of 1's and 0's in a specific pattern that is long enough for the receiving system to lock onto (correlate) and synchronise at the appropriate bit rate. Checksum is a Cyclic Redundancy Check and is normally a delay line with XOR'ed taps fedback into the delay line input. (The feedback bit gives you the "cyclic" term) There are many many text books that explain CRC generation. It can be as big or small as you like. If it's a PC you are talking to then I don't know the correct polynomial for the CRC in this circumstance. You notice how again you can break this down into smaller and smaller bits. If it's a PC you're talking to get the speification of the interface and read it. Then just try a simple terminal program and turn off all fancy handshaking or parity checking. Just try raw data communications. When that works try adding CRC (parity) etc etc. Pete -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body