Instead putting negative mark (-) at front of measured temperature, it just continues to measeure down to zero, and up, like is measuring positive temp. Here is the code, tell me where i'm wrong.
it measures for instance 5.00,4.00,3.00,2.00,1.00,0.00,1.00,2.00,3.00,4.00,5.00....
dim LCD_RS as sbit at RD2_bit
LCD_EN as sbit at RD3_bit
LCD_D4 as sbit at RD4_bit
LCD_D5 as sbit at RD5_bit
LCD_D6 as sbit at RD6_bit
LCD_D7 as sbit at RD7_bit
LCD_RS_Direction as sbit at TRISD2_bit
LCD_EN_Direction as sbit at TRISD3_bit
LCD_D4_Direction as sbit at TRISD4_bit
LCD_D5_Direction as sbit at TRISD5_bit
LCD_D6_Direction as sbit at TRISD6_bit
LCD_D7_Direction as sbit at TRISD7_bit
' End Lcd module connections
' Set TEMP_RESOLUTION to the corresponding resolution of used DS18x20 sensor:
' 18S20: 9 (default setting can be 9,10,11,or 12)
' 18B20: 12
const TEMP_RESOLUTION as byte = 12
dim text as char[9]
temp as word
sub procedure Display_Temperature( dim temp2write as word )
const RES_SHIFT = TEMP_RESOLUTION - 8
dim temp_whole as byte
temp_fraction as word
text = "000.0000"
' Check if temperature is negative
if (temp2write and 0x8000) then
text[0] = "-"
temp2write = not temp2write + 1
end if
' Extract temp_whole
temp_whole = word(temp2write >> RES_SHIFT)
' Convert temp_whole to characters
if ( temp_whole div 100 ) then
text[0] = temp_whole div 100 + 48
else
text[0] = " "
end if
text[1] = (temp_whole div 10)mod 10 + 48 ' Extract tens digit
text[2] = temp_whole mod 10 + 48 ' Extract ones digit
' Extract temp_fraction and convert it to unsigned int
temp_fraction = word(temp2write << (4-RES_SHIFT))
temp_fraction = temp_fraction and 0x000F
temp_fraction = temp_fraction * 625
' Convert temp_fraction to characters
text[4] = word(temp_fraction div 1000) + 48 ' Extract thousands digit
text[5] = word((temp_fraction div 100)mod 10 + 48) ' Extract hundreds digit
text[6] = word((temp_fraction div 10)mod 10 + 48) ' Extract tens digit
text[7] = word(temp_fraction mod 10) + 48 ' Extract ones digit
Lcd_Out(2, 2, text)
end sub
main:
ANSEL = 0 ' Configure AN pins as digital I/O
ANSELH = 0
text = "000.0000"
Lcd_Init() ' Initialize Lcd
Lcd_Cmd(_LCD_CLEAR) ' Clear Lcd
Lcd_Cmd(_LCD_CURSOR_OFF) ' Turn cursor off
Lcd_Out(1, 1, " Outside temp: ")
Lcd_Chr(2,13,223) ' u drugom redu na 13. mestu ' Print degree character, "C" for Centigrades
' Different Lcd displays have different char code for degree
Lcd_Chr(2,14,"C") ' u drugom redu na 14. mestu ' If you see greek alpha letter try typing 178 instead of 223
'--- Main loop
while (TRUE)
'--- Perform temperature reading DQ linija
Ow_Reset(PORTC, 2) ' Onewire reset signal
Ow_Write(PORTC, 2, 0xCC) ' Issue command SKIP_ROM
Ow_Write(PORTC, 2, 0x44) ' Issue command CONVERT_T
Delay_us(170)
Ow_Reset(PORTC, 2)
Ow_Write(PORTC, 2, 0xCC) ' Issue command SKIP_ROM
Ow_Write(PORTC, 2, 0xBE) ' Issue command READ_SCRATCHPAD
temp = Ow_Read(PORTC, 2)
temp = (Ow_Read(PORTC, 2) <<
+ temp'--- Format and display result on Lcd
Display_Temperature(temp)
Delay_ms(300)
wend
end.
