Mam pytanie, opracowywal ktos kompletna procedure odczytu SHT? Skopiowalem ten kod z sampla do AVR , troszke poprawilem (na 89S52) i sie odczytuje..ale wyswietla wiekszosc czasu 18,9stopnia i 42,6 % wilgotnosci Troche malo prawdopodobne wyniki ale reaguje na chuchniecie (chyba tak sie to pisze) Wilgotnosc podskakuje do 82% pozniej gwaltownie spada do 35% i znowu stabilne do znudzenia 42,6%!! Moze cos jest nie tak w obliczeniach Jak uniknac stosowania zmiennych single i zrobic to tylko na wordach. Jak ktos ma jakies doswiadczenie w programowaniu tego czujnika prosze o pomoc
Dim Ctr As Byte
Dim Dataword As Word
Dim Command As Byte
Dim Dis As String * 20
Dim Calc As Single
Dim Calc2 As Single
Dim Rhlinear As Single
Dim Rhlintemp As Single
Dim Tempc As Single
Dim Tempf As Single
Const C1 = -4
Const C2 = 0.0405
Const C3 = -0.0000028
Const T1c = .01
Const T2 = .00008
Const T1f = .018
Dim Datavalue As Word
Dim Databyte As Byte
************w petli co sekunde
Command = &B00000011
Call Getit 'Get the temperature, puts result in "dataword" for us
'
' Tempf = T1f * Dataword
' Tempf = Tempf - 40
Tempc = T1c * Dataword 'get celcius for later calculations and for "the rest of the world"
Tempc = Tempc - 40
Dis = Fusing(tempc , ###.#)
Lcd " T " ; Dis ; " " ; Chr(0) ; "C "
Command = &B00000101
Call Getit 'get the humidity
Calc = C2 * Dataword
Calc2 = Dataword * Dataword 'that "2" in the datasheet sure looked like a footnote for a couple days, nope it means "squared"!
Calc2 = C3 * Calc2
Calc = Calc + C1
Rhlinear = Calc + Calc2
'Dis = Fusing(rhlinear , "##.##")
'Print "Humidity adjusted for linear = " ; Dis
Calc = T2 * Dataword
Calc = Calc + T1c
Calc2 = Tempc - 25
Calc = Calc2 * Calc
Rhlintemp = Calc + Rhlinear
Dis = Fusing(rhlintemp , ##.#)
Lowerline
Lcd "RH " ; Dis ; " % "
Sub Getit
'start with "transmission start"
Set Sck
Reset Dataout
Reset Sck
Set Sck
Set Dataout
Reset Sck
'now send the command
Shiftout Dataout , Sck , Command , 1
' Ddrb = &B11111101 'datain is now input
' Config Pinb.1 = Input 'datain
Set Sck 'click one more off
Reset Sck
' Waitus 10 'no idea why, but it doesn't work without it!
' Delay
$asm
nop
nop
$end Asm
Bitwait Dataout , Reset 'wait for the chip to have data ready
Shiftin Dataout , Sck , Databyte , 1 'get the MSB
Datavalue = Databyte
' Ddrb = &B11111111
' Config Pinb.1 = Output
Reset Dataout 'this is the tricky part- Lot's of hair pulling- have to tick the ack!
Set Sck
Reset Sck
' Ddrb = &B11111101 'datain is now input
' Config Pinb.1 = Input
Shiftin Dataout , Sck , Databyte , 1 'get the LSB
Shift Datavalue , Left , 8
Datavalue = Datavalue Or Databyte
'don't tick the clock or ack since we don't need the CRC value, leave it hanging!
Dataword = Datavalue
' Ddrb = &B11111111
' Config Pinb.1 = Output
Reset Dataout
Set Sck
Reset Sck
' Ddrb = &B11111101 'datain is now input
' Config Pinb.1 = Input
Shiftin Dataout , Sck , Databyte , 1 'not using the CRC value for now- can't figure it out! Anybody know how to impliment?
'Print "CRC value was - " ; Databyte
' Ddrb = &B11111111
' Config Pinb.1 = Output
Set Dataout
Set Sck
Reset Sck
End Sub
[tex]
te linijki z apostrofem sa nieaktywne [/tex]