HEDS5540 optical encoder

[richard]

frac= ((posn1+posn2)//100 +10)/10 ;round it up

is incorrect , it will round the number up always

frac= ((posn1+posn2)//100 +5)/10 ;round it up

is the way to round the number up if the last digit is 5 or more

[richard]

using n-bit math

result

ready v3
turns 23 f 489
33609 3664.3145
turns 23 f 486
33606 3663.9875
turns 23 f 484
33604 3663.7694

 Include "N-Bit_MATH.pbp" 
 
enc_new VAR BYTE   bank0
enc_old VAR BYTE   bank0
enc_counter VAR WORD   bank0
Flag var BYTE        bank0
tmp         var  byte[4]
res         var  byte[4]
tmp1        var  byte[4]
posn        var WORD
turns       var word
frac        var WORD
 
 
 
; Set variable value @ startup
Flag = 1                   ;preset a value    for testing
enc_new = 0
enc_old= 0
enc_counter = 33609      ;preset a value    for testing

 
Main_Loop:     
if Flag = 1 then
turns=  enc_counter /1440
frac=   enc_counter //1440
serout2 PORTa.0,84, [13,10,"turns ",#turns,9,"f ",#frac ] 
if frac then
@  MOVE?CP 157000, _tmp  
@  MOVE?WP _frac, _tmp1  
@  MATH_MUL  _tmp1, _tmp, _res 
@  MOVE?CP 1440000, _tmp
@  MATH_DIV  _res, _tmp, _tmp1
@  MOVE?PW _tmp1, _posn
@  MOVE?CP 144, _tmp
@  MATH_DIV  REG_Z, _tmp, _tmp1
@  MOVE?PW _tmp1, _frac
endif
posn=posn+turns*157
serout2 PORTa.0,84, [13,10,#enc_counter,9,dec4 posn,".",dec4 frac       ] 
 
 
 
Flag = 0
endif
goto Main_Loop
end

[louislouis]

I try to compile your code. I downloaded the N-Bit_MATH.pbp include, but the compiler stops with this error message:
"Bad data type"

If I try to compile only the N-Bit_MATH.pbp (only for test) and its do not compile. Stops on first line:
REG_X VAR BYTE[PRECISION] BANK0 SYSTEM
with the same error message MCU is the same 16F628A, For test I try also 16F688 with the same result. Something I'am doing wrong, I think.

[HenrikOlsson]

You need to define the constant PRECISION and assign it a value equal to the number of bytes to use for the values in the math routine. And you need to do this before including N-Bit. In this case it looks like Richard opted for 32bit values (4 bytes)

PRECISION CON 4 SYSTEM    '32bit values
Include "N-Bit_Math.pbp"

If you open the N-Bit file you'll find a link to the thread on this forum: http://www.picbasic.co.uk/forum/showthread.php?t=12433

/Henrik.

[louislouis]

Yes, right. I forgot this line. After putting this line as you say the code compiles OK. Now I do some testing and trying to understand the code.