timer2 explanation

mtheriault2000 · Joined: 12 Oct 2005 Posts: 9

Hello

I want to use the Timer2 and Int0 at the same time. I want to measure a minimum time that an event occured on the Int0. I just can't have both working together

I'm using a 82S8252 with a 10mhz crystal. I want to use the Timer2 as a time base for my programm. This part of prg is used to detect the presence of a thoot over a metal gear, validate it and increase or decrease a Position counter depending of the value of the Sens bit P0.4(sens of rotation).

To resolve bad reading cause by vibration, i want to use a Counter to validate the presence of the sensor over the gear .

The problem is that the timer2 stop working when an Int0 occured.
Any help whill be appreciated

Martin Theriault

Here is a copy of this part of my prog.

$regfile = 89s8252.dat
$crystal = 10000000
$large
Config Lcd = 20 * 4
Sens Alias P0.3
Gear Alias P0.4
Dim Stop_timer As Bit
Dim Mili_sec As Integer
Dim Seconde As Byte
Dim Counteur As Integer
Dim Position As Integer ' Position par rapport au début
Dim Int0_bit As Bit
Const Numberofthoots= 48
'Set Clkreg
Set Sens
Set Gear
Set Tcon.0 ' Trigger Int0 By Falling Edge.

Config Timer2 = Timer , Gate = Internal , Mode = 0 , Direction = Down
On Timer2 Timer2_int
Load Timer2 , 50000 ' 15 mili secondes

'Priority Set Int0
Enable Int0
Enable Interrupts
Reset Int0_bit
'enable the interrupt
On Int0 Count_gear
Cls
Reset Int0_bit
Position = 1
Mili_sec = 0
Seconde = 0
Enable Timer2
Start Timer2

Do
Home
Lowerline
Lcd Position ; " " ; "g: " ; Gear ; " sens:" ; Sens ; "i: " ; Int0_bit
Locate 3 , 1
Lcd Counter; " " ; Seconde ; " " ; Mili_sec

Loop
End

Count_gear:
Disable Int0
Mili_sec = 0
Compteur = 0
Seconde = 0
Start Timer2
While Mili_sec <= 10
Home
Lcd Mili_sec
If Gear = 0 Then
Incr Compteur
Else
Compteur = 0
End If
If Compteur > 5000 Then
If Compteur > 500 Then
If Sens = 1 Then
Incr Position
If Position > Numberofthoots Then
Position = 1
End If
Else
Decr Position
If Position < 1 Then
Position = Numberofthoots
End If
End If
End If
End If
Wend
'Set Int0_bit
Enable Int0
Set Tcon.0
Return

Timer2_int:
Incr Mili_sec
If Mili_sec = 100 Then
Incr Seconde ' 100*10 miliseconde = 1 seconde
Mili_sec = 0
End If
Reset T2con.7
Return