Post by thread:Simple Program

part 0 434 bytes <META content='"MSHTML 5.00.0910.1309"' name=GENERATOR></HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial>I have a simple project to move a motor one direction, stop, then the other direction. Anyone interested in writing it with the PIC 16F84?</FONT></DIV> <DIV><FONT face=Arial>spam_OUTtomTakeThisOuTcomtronix.com</FONT></DIV></BODY></HTML> </x-html>

Tom, if they are small motors, I suggest the excellent MotorMind B modules from http://www.solutions-cubed.com. They are so easy to interface to from the PIC. -Bill Arkin **25 Years of Laser Services** Holo-Spectra Inc. 7742B Gloria Ave. Van Nuys, CA 91406 818 994-9577 http://www.lasershs.com -----Original Message----- From: Tom <.....tomKILLspam@spam@COMTRONIX.COM> To: PICLISTKILLspamMITVMA.MIT.EDU <.....PICLISTKILLspam.....MITVMA.MIT.EDU> Date: Monday, February 15, 1999 6:13 PM Subject: Simple Program I have a simple project to move a motor one direction, stop, then the other direction. Anyone interested in writing it with the PIC 16F84? EraseMEtomspam_OUTTakeThisOuTcomtronix.com

Thanks for your reply. One port (#1) on the 16F84 is to connect to a momentary switch. When depressed, port (#2) will stay HI while port (3#) stays LOW. Depressed again, the ports 2 & 3 will go low. Depress again and port 2 goes LOW and 3 goes HI. These ports are driving 2 SS Relays which are connected to forward and reverse windings of an AC motor. The motor has limit switches and stops, opening the connection to that winding. Tom {Original Message removed}

The one thing I see here that just screams out from this message is an absolute need to be sure the momentary switch is debounced. For those who have been on the PIC list for a while, the subject of the best way to do this comes up regularly and there are probably three perfectly valid ways to debounce a switch for every PIC list member so there is no one correct answer. For newcomers, the problem is that most mechanical contacts don't come together or go apart cleanly. They bounce like golf balls do on a hard surface except that they may only make 5 or 6 quick bounces before settling. The bounces are so fast that human eyes and ears can't tell anything unusual happened especially when the result is the ringing of a door bell or the turning on of a lamp, but a PIC or the input to a flip-flop can run at literally millions of operations per second and each of those bounces is read as a totally separate event. The result is a totally random and unexpected mode of operation that would satisfy only a betting type. In other words, this will be easy if you make sure to debounce your switch first. Martin McCormick WB5AGZ Stillwater, OK OSU Center for Computing and Information Services Data Communications Group list writes: >Thanks for your reply. One port (#1) on the 16F84 is to connect to a >momentary switch. When depressed, port (#2) will stay HI while port (3#) >stays LOW. Depressed again, the ports 2 & 3 will go low. Depress again and >port 2 goes LOW and 3 goes HI. >These ports are driving 2 SS Relays which are connected to forward and >reverse windings of an AC motor. The motor has limit switches and stops, >opening the connection to that winding.