We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
I've written my first program in Keil uVision2 just to toggle a led with my 8052 microcontroller. Code looks like this: #define P3 *(volatile unsigned int *)0x00B0; //I/O pin to be toggled void main (void) { //declarations unsigned int toggle = 0x01; unsigned long i; //dummy variable to slow down led toggling //main program while (1) { for (i=0; i<=1000000; i++); toggle ^= 0x01; if (toggle == 0x00) * P3 = 0x01; * else * P3 = 0x00; } } The compiler complains about the lines in the if-else construction marked with an "*". It says: syntax error near '=' syntax error near 'elsi' syntax error near '=' I have no clue what I'm doing wrong, maybe there's someone out here who has suggestions?
A few things pop out immediately.
Thanks for your fast answer! The ";" in the define statement was the cause of my problem. However, I do believe that I can set/reset the i/o pin using the pointer, I intend to find out ASAP, I'll let you know what I find out.
"I do believe that I can set/reset the i/o pin using the pointer" You need to define it as an sfr Take a look at the standard header file recommended for this part:http://www.keil.com/dd/chip/3479.htm "I've written my first program in Keil uVision2 just to toggle a led with my 8052 microcontroller." Before you did that, did you follow the Standard Advice: First, you need to read the uVision Getting Started guide, and work through the example projects in it. You need to read the following documents - commonly referred to as "the bible" for the 8051: http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_ARCH_1.pdf http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_PROG_GUIDE_1.pdf http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_HARDWARE_1.pdf Are you also a newbie to 'C' programming in general? If so, you'll also need a good 'C' textbook. Here are some other introductory & reference materials: http://www.keil.com/books/8051books.asp http://www.8052.com/books.phtml http://www.8052.com/tutorial.phtml You will need to read the Manuals for the C51 Compiler, A51 Assembler, etc, etc,...
However, I do believe that I can set/reset the i/o pin using the pointer, I intend to find out ASAP, I'll let you know what I find out. If it's the standard 8051 P3 that is at SFR address 0xB0, you can't use a pointer to access it. This is clearly presented in the Intel 8051 data book. Jon
"However, I do believe that I can set/reset the i/o pin using the pointer, I intend to find out ASAP..." OK, for some, experience is the best teacher.
Forgive me my stubborness. I'll try to get things to work with your suggestions, by declaring a SFR. Thank you all for your support!