serial communication problem

[kindaichi]

hi guys.. i still hv a problem..i just change my code..here's below

INCLUDE "modedefs.bas"
define FOSC 4
define LCD_DREG PORTD
define LCD_DBIT 4
define LCD_RSREG PORTD
DEFINE LCD_RSBIT 2
define LCD_EREG PORTD
define LCD_EBIT 3
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
'HIGH PORTD.1
C VAR WORD


TRISC = %10111111 ' Set TX (PortC.6) to out, rest in
RCSTA = $90 ' Enable serial port & continuous receive
TXSTA = $20 ' Enable transmit, BRGH = 0
SPBRG = 25 ' 9600 Baud @ 0.16%
SPBRGH = 0
BAUDCON.3 = 1 ' Enable 16 bit baudrate generator


define ADC_BITS 10
define ADC_CLOCK 3
define ADC_SAMPLEUS 50

lmtemp var word
temp var byte
quanta con 1250
TRISE = %111
ADCON1 = 0


MAIN:
ADCIN 6, lmtemp
temp = ((lmtemp/100)/2)+8-50
'PORTD.1=1
'C=PORTD.1
'LOW PORTD.1
LCDOUT $FE,1
LCDOUT " Programmed by"
LCDOUT $FE,$C0
lcdout "YAN^S TEMP="
LCDOUT #temp
LCDOUT " C"
'HIGH PORTD.1


HSEROUT [dec temp,10]
HSerout ["The Temp Are Now ",#temp,"C",13]


pause 100
GOTO MAIN
end

it will display something like this... xøxøxxxxø€øøøxxx€x€€ø€€øxøxxxxø€øøøxxx€

is it correct my temperature equation??i think it is not..when i measured voltage, i get 0.81V and it's display 36 C..it suppose display 30 C..how analog voltage convert to digital and what exactly temperature equation to be write into my code??

mcp9700 sensors is an analog signal that is directly proportional (linear) to the temperature and the output voltage is a direct indication of the temperature in 10mV/°C.

plz help me..it's urgent..the due date is next week 15 march..
thanx..

[aratti]

You should first scale lmtemp to volts

Volts = Imtemp/205 [ 205 = 1/(5/1023))]

Than since your sensor Vout = (Tci * Ta) + V0°C

where: Tci = 10 milliVolts and V0°C = 0.5 Volts

Ta= (Vout-0.5)/0.01

Ta = (Vout - 0.5) * 100

Ta = (Vout*100)-50

Al.

[mackrackit]

Sounds like you need to invert the signal.
You can use a MAX232 or a transistor with a couple resistors.