math not working out right

[Ryan]

here is the section of code in question:

dim ch1loop as long
dim rvalue as long
start:
ch1loop=readad10(an0)
ch1loop = ch1loop * 4883
rvalue = (ch1loop*1000)/(5000000-ch1loop)

when i use an a/d value of 95 I should get result of 102.xxxx but it is not coming out right, it works on paper, but not on the pic, what am i missing? this is for a resistance calculation usng a 12f683

[William Roth]

It works ok for me.

How are you determining that is it not working ?

[Ryan]

using a terminal on m y laptop:

chip 12f683, 8 'mhz

config INTRC_OSC_NOCLKOUT, MCLRE=off, WDT=off

Ser_Init

dir gpio.5 out 'tx
dir gpio.4 in '
dir gpio.3 in '
dir gpio.2 in '
dir gpio.1 in '
dir gpio.0 in 'resistance ch1
dim lcdvalue as word
dim ch1loop as long
dim rvalue as long

start:
ch1loop=readad10(an0)
bin2ascii ch1loop
Xmit_rs232 (32) 'space
ch1loop = ch1loop * 4883
rvalue = (ch1loop*1000)/(5000000-ch1loop)
bin2ascii rvalue

'Xmit_rs232 (h'8A') 'send data
'Xmit_rs232 (h'A8')
'Xmit_rs232 (h'00') 'row
'Xmit_rs232 (h'01') 'col
'Xmit_rs232 (h'01') 'number of bytes
'data
'wait 3 s
'Xmit_rs232 (h'8A') 'clear display
'Xmit_rs232 (h'A8')
'Xmit_rs232 (h'FF')
'Xmit_rs232 (h'FF')
wait 2 s
'Xmit_RS232 10
Xmit_RS232 13 'line feed, carriage return
goto start

Sub Ser_Init
;slight adjustment was required for 9600bps delay value

define baud 104 ;expressed as frequency in us

define halfbaud 52 ;place Read of SerRx in middle of bit

define SerTxHigh Set GPIO.5 On

define SerTxLow Set GPIO.5 Off

dir GPIO.5 out ;Tx
SerTxHigh ;Initial RS232 idle state
end sub

sub XMIT_PRINT (PrintData$)
PrintLen = PrintData(0)
if PrintLen = 0 then exit sub
'Write Data
for SysPrintTemp = 1 to PrintLen
XMIT_RS232(PrintData(SysPrintTemp))
next
end sub

Sub XMIT_RS232(Xmit_Byte)#NR
SerTxLow ;Start bit
wait baud us
For cntr = 1 to 8
Rotate Xmit_Byte Right
If Status.C ON Then SerTxHigh
If Status.C Off Then SerTxLow
wait baud us
Next
SerTxHigh ;Stop bit
wait baud us
end sub

sub Bin2ascii (LCDValue)#NR
serttho = 0
sertho = 0
SERCEN = 0
SERDEC = 0
SERUN = 0
LCDValueTemp = 0

lcdvaluetemp = lcdvalue / 10000
SERttho = LCDValueTemp + 48
if serttho<>48 then
Xmit_rs232 (Serttho)
end if
LCDValue = lcdvalue - LCDValueTemp * 10000

lcdvaluetemp = lcdvalue / 1000
SERtho = LCDValueTemp + 48
'if sertho<>48 then
Xmit_rs232 (Sertho)
'end if
LCDValue = lcdvalue - LCDValueTemp * 1000

lcdvaluetemp = lcdvalue / 100
SERCEN = LCDValueTemp + 48
Xmit_rs232 (SerCen)
LCDValue = LCDValue - LCDValueTemp * 100

LCDValueTemp = LCDValue / 10
SERDEC = LCDValueTemp + 48
Xmit_rs232 (Serdec)
LCDValue = LCDValue - LCDValueTemp * 10

SERUN = LCDValue + 48
'if serun<>48 then
Xmit_rs232 (46) '"."
Xmit_rs232 (Serun)
'end if
end sub

[William Roth]

Ryan,

If you upgrade to the latest GCB, I will be glad to help. But I cannot support this
old bit-banged serial code.

Possibly someone else will have the time to sort through the code and find the problem(s)

Also please describe the problem in less vague terms. " .. is not coming out right" does not tell us very much.

Does anything come out? If so what?

Are you referring to what is shown on the LCD display or on a Terminal Application ?

Willliam

[Ryan]

I'm downloading the new version, so can you help me get this up and runnig with the new version, im sure there will be new wording and what not to learn

[Ryan]

okay, i hvae this now:

chip 12f683, 8 'mhz

config INTRC_OSC_NOCLKOUT, MCLRE=off, WDT=off

InitSer 1, r9600, 1, 8, 1, none, normal

define SendAHigh Set gpio.5 ON

define SendALow Set gpio.5 OFF

dir gpio.5 out 'tx
dir gpio.4 in '
dir gpio.3 in '
dir gpio.2 in '
dir gpio.1 in '
dir gpio.0 in 'resistance ch1
dim ch1loop as long
dim rvalue as long

start:
'SerPrint 1, ReadAD10(an0)
'SerSend 1, 32
wait 2 s
ch1loop=readad10(an0)
ch1loop = ch1loop * 4883
rvalue = (ch1loop*1000)/(5000000-ch1loop)
resist =rvalue
SerPrint 1, resist
wait 3 s
SerSend 1, 13
SerSend 1, 10
goto Start

How do i make it so i can put send each character seperate, i need to put a decimal between the last two digits and also need to make it so it sends the same number of characters each time and fills the empty spots with either spaces or zeros?
Thanks

[Ryan]

I got it!

[William Roth]

Good,

On another note. You do realize that your math will overflow to zero if the AD input value is greater than about 880.

880 * 4883 * 1000 = 4297040000