ADC and TRIAC code

naseerak · Joined: 08 Nov 2008 Posts: 138

Hi
I am using AN125 code here but not getting any pulses on PB.2 as mentioned in the application note what could be the problem.
CODE:
'*************************************************
'*************************************************
'** **
'** Simple Triac Dimmer DEMO **
'** **
'** Using Zero Crossing Detection **
'** **
'** by Mike Crean C/O autlec@optusnet.com.au **
'** Perth Western Australia **
'** **
'** 8515, 8535 & other AVR Micros. **
'** **
'** This Demo is set up for a 50Hz mains **
'** supply. There are comments in the **
'** program for changes to 60Hz. **
'** The micro was set for an 8meg. clock. **
'** May need some mod's if lower speeds **
'** are used. **
'** **
'** For stable operation use the 2nd zero **
'** crossing circuit (4069) in AN125 **
'** (mcselec.com). **
'** **
'** WITH MAINS DISCONNECTED FROM TRIAC or LOAD **
'** **
'** Connect a Dual Trace CRO to PortB.2 Triac **
'** drive & PortD.2 Zero Crossing input. **
'** **
'** The relation between zero crossing & the **
'** Triac drive will be seen. Can be used to **
'** set program values for other mains **
'** frequencies (Hz). The values must be set & **
'** checked so Triac trigger is after zero **
'** crossing & before next zero crossing. If **
'** incorrect the Triac & or load may draw **
'** high current & cause other serious faults. **
'** **
'** NOTE|- Uses a NON zero crossing MOC Triac **
'** driver connected from PortB.2 via a 330R **
'** resistor to neg. DC micro supply **
'** **
'** The following program defaults to auto **
'** repeat dimming. If an RS232 interface is **
'** connected it can be changed to one shot **
'** auto dimming or variable dimming if a POT. **
'** is connected to AD0 (5k, wiper to AD0 & **
'** one end to neg. (-) and other to 5V+ **
'** **
'** For hardware refer to Triac/MOC **
'** manufacturers application notes. **
'** Uses a sensitive gate Triac. **
'** **
'** DANGER - WARNING **
'** ---------------- **
'** High voltages are present when equipment **
'** is connected to a mains supply. **
'** **
'** Some Authorities may only allow suitably **
'** qualified & licensed persons to connect **
'** any such equipment to a high voltage **
'** supply. **
'** **
'** Take CAUTION. Avoid electric SHOCK **
'** **
'** E&OE **
'** **
'*************************************************
'*************************************************

'$sim
$regfile = "8535def.dat"
$crystal = 8000000
$baud = 9600
Config Adc = Single , Prescaler = Auto , Reference = Avcc
Config Timer0 = Timer , Prescale = 1 '** Sets T0 / rate
'** Values (1,8,64,256 &
Config Int0 = Falling '** Interrupt 0 (Int0)
Config Portd = Input '** Set Portd to Inputs
Config Portb = Output '** Set Portb to Outputs

'** Config variables

Dim Rx As Byte , Channel As Byte , Afdm As Byte , Onesh As Byte
Dim Reprate As Byte , Afdmchk As Byte , Afchk As Byte
Dim Count As Integer , Td As Integer
Dim Dstuff As Single
Dim W As Word , Stuff As Word

Afdm = 1 '** Set to auto dim (default)
Afchk = 0
Afdmchk = 0
Onesh = 0
Reprate = 5 '** Will repeat every 5 Secs.

On Urxc Rec_isr '** Call Recv. Interrupt service routine
Enable Urxc '** Enable ISR calls
On Timer0 Tim0_isr '** Call Timer0 ISR
Enable Timer0 '** Enable Timer0 ISR calls
Enable Int0 '** Enable Int0 ISR calls
On Int0 Int0_isr '** Call Int0 ISR
Enable Interrupts '** Enable all interrupts
Stop Timer0 '** Stop the Timer
Start Adc '** Start the Adc

'** Have used PortB.2 as MOC - Triac driver as you may use PortA as ADCs

Portb.2 = 0 '** Pull PortB.2 Low (Triac OFF)

'***** MAIN PROGRAM LOOP *****

Do

nop

Loop

'** Get the Zero Crossing Point from Hardware on PortD.2 **
'** This signal is normaly HIGH and goes low on falling + half cycle **
'** Zero Crossing is detected on the falling edge of Int0 **
'** For Hardware see AN125 at mcselec.com **

Int0_isr: '** Interrupt0 Interrupt Service Routine

Start Timer0 '** Start Timer 0
Gosub Getadc '** Get the ADC values
'** The ADC conversion & other
'** calculations are in this section
'** because they take the most time.

Return '** Return to MAIN Program Loop

'** If a Pot. is used as a dimmer then use PortA.0 for input as 0 - 5V **

Getadc:

'** Read the ADC channels (10 bit ADC) = (0 to 1023 count)
'** ADC vref has to be 5V+ (use a fillter - 330R & 100nf) **

For Channel = 0 To 7
W = Getadc(channel) '** Loop to read 8 ADCs
If Channel = 0 Then Stuff = W '** Put ADC0 into Stuff (from Pot.)
Next Channel

If Afdm = 0 Then '** Set to Auto Dim Mode
If Afdmchk = 0 Then
Td = 1 : Afdmchk = 1
End If

If Td < 231 Then '** Change 231 value for 60Hz
Td = Td + 1
End If

If Td > 230 Then '** Change 230 value for 60Hz
If Afchk = 0 Then
Portb.2 = 0
Afchk = 1
Count = 0
End If
End If

If Onesh = 0 Then '** Set Auto Repeat mode ON
If Afchk = 1 Then
Count = 0 : Afchk = 0 : Afdmchk = 0
Wait 4 '** Wait 4 Sec. before Auto Repeat
End If
End If

End If

If Afdm = 1 Then '** Set in Dimmer Mode
Dstuff = Stuff / 4.55 '** Put Stuff (word) into Td (Integer)
Td = Dstuff '** Change 4.55 value for 60Hz
End If

If Td < 1 Then '** If Td < 0 crossing point
Td = 1 '** set Td > 0 crossing point
End If

If Td > 235 Then '** If Td is > next 0 crossing point
Td = 235 '** set Td < next 0 crossing point
End If '** Change 235 values for 60Hz

Return

Tim0_isr: 'Timer0 ISR, called if T0 overflows

If Afchk = 1 Then '** Jump this lot if in Auto Dim Mode
nop
Goto Skiptriac
End If

Count = Count + 1 '** Start counter (No. of interrupts)
'** counts each time T0 overflows
If Count > Td Then '** If the count > AD0 / 3 then send
Count = 0 '** pulses & set count to 0
Stop Timer0 '** Stop Timer 0
'** Send 3 pulses to the Triac
Set Portb.2 '** Turn Portb.2 on (high), PIN 3
Waitus 100 '** Wait 100 u/s
Reset Portb.2 '** Turn Portb.2 off (low), PIN 3
Waitus 100 '** Wait 100 u/s
Set Portb.2 '** Repeat for 3 pulses
Waitus 100
Reset Portb.2
Waitus 100
Set Portb.2
Waitus 100
Reset Portb.2
Waitus 100
End If

Skiptriac:

Return '** Return to MAIN Program Loop

Rec_isr: '** Recv. buffer ISR

Rx = Inkey() '** Get Char (ASCII) from Recv. buffer

If Rx = 63 Then '** 63 = chr ?
Print : Print " Dimmer Test" '** Send to Tx buffer
Print " -----------------------------"
Print : Print " ? - Help"
Print " | - Send Ad0 to buffer"
Print " ! - Set to auto fade (default)"
Print " @ - Set to dimmer mode (Pot.)"
Print " # - Set auto fade to repeat (default)"
Print " $ - Set auto fade to one shot"
End If

If Rx = 124 Then '** 124 = chr |
Print : Print " Ad0 = " ; Stuff '** Send Ad0 to Tx buffer
Print " Td = " ; Td
Print " Afdm = " ; Afdm
Print " Afdmchk = " ; Afdmchk
End If

If Rx = 33 Then '** 33 = chr !
Afdm = 0 : Afchk = 0 '** Set to Auto Fade (default)
End If

If Rx = 64 Then '** 64 = chr @
Afdm = 1 : Afchk = 0 '** Set to Dimmer mode
End If

If Rx = 35 Then '** 35 chr #
Onesh = 0 : Afdm = 0 '** Auto Fade Repeats every 5Secs.
End If

If Rx = 36 Then '** 36 chr $
Onesh = 1 : Afdm = 0 '** Auto fade is one shot
End If

Rx = 0

Return '** Return to MAIN Program Loop

End '** End of program and code space

'***** E&OE *****
Here is my proteus file.