hi sir i need one help now iam doing project on 89c51 using C51 Evaluation Software i converted 0-5 analog volatge to 0-5 digital voltage . now i want convert digital data to pressure my output should be like this 0v 1.1E-1 3v 4.1E-4 0.1 1.2E-1 4v 5.1E-5 1v 2.1E-2 5v 6.1E-6 2v 3.1E-3 i want 500 values in between 0 to 5 volts how to calibrate the voltage interms of preesure what logic i want use to convert Voltage to pressure my C51 not taking floting oparations please help regards chandra sri
hi sir thank you sir i tried this program { unsigned int voltage; unsigned char *pressure_string[] ={"11E-1","12E-2","13E-3"}; printf( "Voltage %u mV = Pressuse %s", voltage*10, pressure_string[voltage] ); } it is showing folling out put "voltage 10mv=pressure 13E- " it is not showing full value. regards nari
When you posted your data as
0.00v =1.1E-1 0.01v =1.2E-1 0.02v =1.3E-1 . . 1.00 =2.1E-2 . . 2.00 =3.1E-3 . . 3.00 =4.1E-4 4.00 =5.1E-4 5.00 =6.1E-5
char * pressure_string[] = { "1.1E-1", // Index 0 corresponds to 0mv "1.2E-1", // Index 1 corresponds to 10mv "1.3E-1", // Index 2 corresponds to 20mv : : }
{ unsigned int voltage; unsigned char *pressure_string[] ={ "11E-1", "12E-2", "13E-3" }; printf( "Voltage %u mV = Pressuse %s", voltage*10, pressure_string[voltage] ); }
printf( "Voltage %u mV = Pressuse %s\r\n", voltage*10, pressure_string[voltage] );
Hi sir I assign a value to 'voltage' now iam geting correct values. up to 24 string elements [array elements]it showing correct. Above the 24 elements it is compiling but it is showing linking error the error is: "Build target 'Target 1' linking... *** ERROR L107: ADDRESS SPACE OVERFLOW SPACE: DATA SEGMENT: _DATA_GROUP_ LENGTH: 0071H Program Size: data=123.1 xdata=0 code=1559 Target not created*/" above the 50 elements it is not compiling and showing this error . the error is: " compiling forum.c... MAIN\FORUM.C(19): error C241: 'main': auto segment too large main\forum.c - 1 Error(s), 0 Warning(s). " regards chandu
*** ERROR L107: ADDRESS SPACE OVERFLOW SPACE: DATA This means that there is not enough memory available in DATA memory space to hold all the variables you have declared. Which is not surprising, as the 8052 only has 128 bytes of DATA memory. Since your programm will most likely not change the contents of the string array at run-time, you could simply store the array in CODE space instead. If the program does need to change the contents, and your device has enough XDATA memory, store the array there instead. Refer to the Cx51 manual for more information on memory types and areas: http://www.keil.com/support/man/docs/c51/c51_extensions.htm
Chandra, Is it just that English is not your first language, or do you really not understand the word "OVERFLOW" ? See: http://www.keil.com/forum/docs/thread7364.asp As Christoph says, the data in the lookup table is constant - it will not change at run-time - so you should put it into CODE space. You might find that you exceed the code space limit of the evaluation version, though...
MAIN\FORUM.C(19): error C241: 'main': auto segment too large main\forum.c - 1 Error(s), 0 Warning(s).
thank you sir thank you for your valueble answers Hear in my project iam using 4 seven segment display for to display the pressure. up to now iam displaying the pressure on the serial window. pleace tell how to display the data on 7 segment display with out using printf statement. Because printf is taking lot of memory . regards chandu
"in my project iam using 4 seven segment display for to display the pressure." Do you mean a four-digit 7-segment display? If so, how do you plan to display, for example, "4.1E-4" on four 7-segment digits:
4. = 1st digit 1 = 2nd digit E = 3rd digit - = 4th digit 4 = Oops! no more digits!!
Textbook time, again! Andy, do not come to the US, we have laws against cruel and unusual punishment :) Erik
we have laws against cruel and unusual punishment Textbook time may be cruel, but it is certainly not unusual, and therefore perfectly fine. :)
"Textbook time ... is certainly not unusual" It seems to be becoming increasingly unusual amongst today's students... :-(
hi sir this is my code { unsigned int voltage; unsigned char *pressure_string[] ={"3.07E-12","1.22E-10","6.56E-10"); v=0x02; voltage=voltage*50; P1=string[voltage]; } For voltage=0x02 carresponding pressure is 6.56E-10 from table. that is P1=6.56E-10; sir my doubt is PORT 1 well takes only 1 byte (8bits) then how it takes 6.56E-10; and how to devide the pressure 6.56E-10 into "6",".=constant","5","6","E=constant", "-=constant","1","0" . sir here iam using seven numbers 7segment Led display for displaying the pressure. thank you sir Regards chandu
Hi sir how to divide the "string" into singal elements example: string={"3.56E-12") in to "3", "." ,"5","6","E","-","1","2". Thank you Regards chandu
Stop! Now!! You are struggling with absolutely basic concepts of both 'C' programming and, apparently, the hardware itself. You seriously need to set this project aside, go back to basics, and get a proper understanding in the 'C' Language Get yourself a good book, and study it: http://www.keil.com/books/8051books.asp http://www.8052.com/books.phtml "my doubt is PORT 1 well takes only 1 byte (8bits) ... i am using seven numbers 7segment LED display" Sure, all the 8051's ports are 8 bits (1 byte) wide. So how have you connected seven 7-Segment digits to your 8051? Obviously, the way you write stuff to the display will depend entirely on how it is connected to the 8051!!