MrDEB
Well-Known Member
Working on a simulated candle that flickers as per real candle. Using swordfish I got this code working BUT the results look more like a strobe light (using a 18F2420 for test of code at present) and thinking perhaps a PWM output would be better. Well the 18F2420 only has two PWM outputs but I can't get the second one to work (using the PWM2 module).
In the final design I am using a 18F13K22(cost was deciding factor as I am planning on 15 of these candles) which has 4 PWM outputs. Just need to breadboard a circuit and test but how to implement the PWM2 module for 3 outputs as in my proposed schematic. Didn't realize the 18F13K22 has 4 PWM outputs until I received in the mail yesterday and getting ready to breadboard said pic. ANY suggestions on either slowing down the present code so it doesn't look like a strobe light and/or using the PWM2 module on the 18F13K22. NOTE the data sheet mentions pullup or pull-down on the outputs but using the N mosfets should take care of this?
In the final design I am using a 18F13K22(cost was deciding factor as I am planning on 15 of these candles) which has 4 PWM outputs. Just need to breadboard a circuit and test but how to implement the PWM2 module for 3 outputs as in my proposed schematic. Didn't realize the 18F13K22 has 4 PWM outputs until I received in the mail yesterday and getting ready to breadboard said pic. ANY suggestions on either slowing down the present code so it doesn't look like a strobe light and/or using the PWM2 module on the 18F13K22. NOTE the data sheet mentions pullup or pull-down on the outputs but using the N mosfets should take care of this?
Code:
{
*****************************************************************************
* Name : UNTITLED.BAS *
* Author : [select VIEW...EDITOR OPTIONS] *
* Notice : Copyright (c) 2013 [select VIEW...EDITOR OPTIONS] *
* : All Rights Reserved *
* Date : 11/18/2013 *
* Version : 1.0 *
* Notes : *
* : *
*****************************************************************************
}
{
*****************************************************************************
* Name : candle routine.BAS *
* Author : Doug Bezaire *
* Notice : Copyright (c) 2010 [select VIEW...EDITOR OPTIONS] *
* : All Rights Reserved *
* Date : 4/1/2010 *
* Version : 1.0 *
* Notes : *
* : *
*****************************************************************************
}
{
*****************************************************************************
* Name : UNTITLED.BAS *
* Author : Doug Bezaire *
* Notice : Copyright (c) 2010 [select VIEW...EDITOR OPTIONS] *
* : All Rights Reserved *
* Date : 3/26/2010 *
* Version : 1.0 *
* Notes : *
* : *
*****************************************************************************
}
Device = 18F2420
Clock = 8
Include "InternalOscillator.bas"
Include "RandGen.bas"
Include "Utils.bas"
Dim TMR2IE As PIE1.1, // TMR2 interrupt enable
TMR2IF As PIR1.1, // TMR2 overflow flag
TMR2ON As T2CON.2, // Enables TMR2 to begin incrementing
Signal_Pin As PORTB.0 // Signal output to frequency meter
Dim Red_Pin As PORTA.2, //was b.0
Green_Pin As PORTA.0, //was b1
Blue_Pin As PORTA.1, //was b2
Red_Duty As Byte,
Green_Duty As Byte,
Blue_Duty As Byte,
Red_DutyVal As Byte,
Green_DutyVal As Byte,
Blue_DutyVal As Byte,
RandomVal As Byte
Dim uS As Word,
mS As Word
// ranval(1)as word
Interrupt TMR2_Interrupt()
High(Signal_Pin)
Save(0) // Back up system variables
If TMR2IF = 1 Then // Check if the interrupt was from TMR2
TMR2IF = 0 // Clear the TMR2 interrupt flag
uS = uS + 50
If uS >= 1000 Then
uS = uS - 1000
Inc(mS)
EndIf
Inc(Red_DutyVal)
Inc(Green_DutyVal)
Inc(Blue_DutyVal)
If Red_DutyVal > Red_Duty Or Red_Duty = 0 Then
Red_Pin = 0
Else
Red_Pin = 1
EndIf
If Green_DutyVal > Green_Duty Or Green_Duty = 0 Then
Green_Pin = 0
Else
Green_Pin = 1
EndIf
If Blue_DutyVal > Blue_Duty Or Blue_Duty = 0 Then
Blue_Pin = 0
Else
Blue_Pin = 1
EndIf
EndIf //
Restore // Restore system variables
Low(Signal_Pin)
End Interrupt
Private Sub TMR2_Initialize()
TMR2ON = 0 // Disable TMR2
TMR2IE = 0 // Turn off TMR2 interrupts
PR2 = 149 // TMR2 Period register PR2
T2CON = %00000001 // T2CON 0:1 = Prescale
// 00 = Prescale is 1:1
// 01 = Prescale is 1:4
// 1x = Prescale is 1:16
// 3:6 = Postscale
// 0000 = 1:1 postscale
// 0001 = 1:2 postscale
// 0010 = 1:3 postscale...
// 1111 = 1:16 postscale
TMR2 = 0 // Reset TMR2 Value
TMR2IE = 1 // Enable TMR2 interrupts
TMR2ON = 1 // Enable TMR2 to increment
Enable(TMR2_Interrupt)
End Sub
// Start Of Program...
Low(Red_Pin)
Low(Green_Pin)
Low(Blue_Pin)
Red_Duty = 255
Green_Duty = 0
Blue_Duty = 0
Red_DutyVal = 0
Green_DutyVal = 0
Blue_DutyVal =0
uS = 0
mS = 0
RandGen.Initialize(128) // Initialize the Random Number generator
TMR2_Initialize // Setup and enable TMR2
While True // Create an infinite loop
RandomVal = RandGen.Rand // Grab a random number from 0 to 255
// Select RandomVal // Find out what colour to increase/decrease
//Case 0 To 42
Red_Duty =RandomVal-5
//mS = 0
// (Red_Duty)=Rand(1)
// Repeat
// Until mS = 19
// and Red_Duty>0
// endif
//Case 43 To 84
If Red_Duty > 0
Then mS = 0
Repeat
Until mS = 20
Dec(Red_Duty)
DelayMS(5000)
EndIf
// Case 84 To 127
Green_Duty =RandomVal-20
//Then mS = 0
// Repeat
// Until mS = 19
// Inc(Green_Duty)
// EndIf
// Case 128 To 170
If Green_Duty > 0
Then mS = 0
Repeat
Until mS = 40
Inc(Green_Duty)
DelayMS(5000)
EndIf
// Case 170 To 212
Blue_Duty = RandomVal-30
// Then mS = 0
// Repeat
// Until mS = 19
// Inc(Blue_Duty)
// EndIf
// Case 212 To 255
If Blue_Duty > 0
Then mS = 0
Repeat
Until mS = 20
DelayMS(5000)
Inc(Blue_Duty)
EndIf
Wend
End
the chip you have has 4 timers so software pwm is the way to go with this chip.
