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Iam connecting microcontroller 8051 with my PC COM1 port to have serial communication. To have same voltage levels between PC and 8051 i have used MAX232 but i need to know what other components like capacitors and resistor i need to connect in between controller and MAX232. i have the data sheet but information is limited. so can any one suggest capacitor value and quanity and other minor components.
I'm on vacation but I've been thinking about making certain threads "closed to new posts". From time to time I do go and delete threads that are non-sensical. Maybe I just need to do more of that. Jon
I think "closing to new posts" may be a reasonable choice in addition to deleting threads when it makes sense. To your credit, you have not (in my estimation) been "heavy-handed" about deleting threads, so I'd imagine you would moderate with the same even temper for threads worthy of consideration of the lesser result of "closing to new posts".
One problem with closing or deleting the begging threads may be that these people will start new ones. That will probably be even more irritating. The very fact that most of these people ask for stuff but don't give an email address shows just how bright they are. I suspect they are mostly students - the type who haven't been to any classes then suddenly find themselves with a project to complete and no idea where to start. As for that long thread started by somebody offering schematics or something, I'd say that was a troll. Stefan
There are a couple of things to consider. 1. If I delete a thread like this one (www.keil.com/.../thread2288.asp) or if I make it inactive (no posting allowed) someone may start a new thread. 2. If I leave it live, other people will uselessly post to it. Those of us "in the know" can leave it unread. Maybe we could implement a voting system that would allow visitors to "rate" a thread. Threads could be marked as useful or useless in the thread list based on the votes they receive. Then, we could more easily decide which threads to prune based on votes. Jon
Here's my $0.02 USD. It seems most of the offenders fall into one or both of two categories -- the clueless and the I-wanna's/gimme's (CMS says apostrophizing in this context is acceptable). The clueless should be tolerated so that they may get one. The I-wanna's/gimme's should not be tolerated for very long. Those who have what wanna's want should be proactive and put their offerings up on a Web/FTP site and simply link to it, and not be reactive by having to "poll" the threads to see if anybody new needs something. So there you have it:
Hi Jon, I have done one simple serial rs232 c program in keil and when download in eprom it produce no output on the termulator.This program is to do serial transmission from 8051 to pc. Here is the code:
/* RS232 SIMPLE TRIAL */ #include <stdio.h> #include <reg51.h> /*Function to initialize RS232 serial port*/ void serial_init() { SCON=0X50; //Setup for 8-bit data TMOD=0X20; //Setup Timer 1 for auto-reload TH1=0XFD; //Setup for 9600 baud TR1=1; //Turn on Timer 1 T1=1; //Indicate Ready to Transmit } /*This func display a null-terminated string on the rs232 port*/ void send_serial(unsigned char*s) { while(*s!=0x0) { SBUF=*s; while(!T1) { } T1=0; s++; } } /*Start of main program*/ main() { unsigned char crlf[]={0x0D,0x0A,0x0}; serial_init(); for (;;) { send_serial("Another test"); send_serial(crlf); } }