Syntax:
word_variable = sqrt ( word )Explanation:
A square root routine for GCBASIC. The function only involves bit shifting, addition and subtraction, which makes it fast and efficient.
This method required a word variable as the input and a word variable as the output. The method will handle arguments of up to 4294.
Command Availability:
Available on all microcontrollers, required MATHS.H include file.
Example:
;Demo: Show the first 100 square roots to 2 decimal places.
;This uses the maths.h include file.
;----- Configuration
#chip 16F88, 8 ;PIC16F88 running at 8 MHz
#config mclr=off ;reset handled internally
#include <maths.h> ;required maths.h
;----- Constants
#define LCD_IO 4 ;4-bit mode
#define LCD_WIDTH 20 ;specified lcd width for clarity only. 20 is the default width
#define LCD_RS PortB.2 ;pin 8 is LCD Register Select
#define LCD_Enable PortB.3 ;pin 9 is LCD Enable
#define LCD_DB4 PortB.4 ;DB4 on pin 10
#define LCD_DB5 PortB.5 ;DB5 on pin 11
#define LCD_DB6 PortB.6 ;DB6 on pin 12
#define LCD_DB7 PortB.7 ;DB7 on pin 13
#define LCD_NO_RW 1 ;ground the RW line on LCD
;----- Variables
dim length as byte
dim i as word
dim valStr, outStr as string
;----- Program
dir PortB out ;all outputs to the LCD
for i = 0 to 100 ;print first 100 square roots
cls
print "sqrt("
print i
print ")="
valStr = str(sqrt(i)) ;format decimal nicely
length = len(valStr)
select case length
case 1:
outStr = "0.00" ;zero case
case 3:
outStr = left(valStr,1)+ "."+right(valStr,2)
case 4:
outStr = left(valStr,2)+ "."+right(valStr,2)
case 5:
outStr = left(valStr,3)+ "."+right(valStr,2)
end select
print outStr ;display results
wait 2 S
next iSupported in <MATHS.H>
