Good day Jiggy-Ninja
Thanks for the advice:
I have modified the code again, and have made a minor advance, (I think).
Please see attached scope shot.
I am using the following code to turn off the square wave at the apex of the triangle wave:
ramplengthpause=(ramplength/3);
if((Dir==-1) && (Dir != +1))
{
digitalWrite(outPin,LOW);
delay(ramplengthpause);
}
The result is seen in the same attached scope shot. The code will commence the square wave exactly where it should. 
And, the code will terminate the square wave at the apex.........
But.... simultaneous to the falling edge of the triangle wave, the code produces a fast pwm cycling (seen as the blue shaded area). Once pwmMin is reached, both waves seem to behave themselves.
If I can eliminate the fast pwm on the falling edge, then maybe I will have it working.
I also tried this code:
do
{
digitalWrite(outPin, LOW);
}
while((Dir==-1) && (Dir != +1));
It does not respond at all........
Here is the complete code as I ran it:
/*
This Sketch will generate a variable volatage ramp signal
simultaneous to a syncronized *boxed* square wave.
//----------------------------------------------------//
Output: PP 7; P2 of ATTiny85 to a 'Low Pass Filter'
Values of cap & resistor to be calculated according to
roll-off frequency appropriate for working PWM freq.
ARDUINO_ATTiny ---/\/\/\--- | ---- INPUT COMPARATOR
|
---
---
|
|
GROUND
This will produce a *nice* voltage ramp/saw tooth waveform.
Can be made *variable* by substituting appropriate potentio-
meter for resistor.
*/
//////////////////////////////////
#include <stdlib.h>
#include <avr/io.h> // Adds useful constants
/// Define Variables ////
int pwmMin=30; // minimum pwm voltage (0-255)
int pwmMax=255; // maximum pwm voltage (0-255)
int ramplength=4; // us
int INTERVAL=30000; // the repeat delay interval; ms.
int delayStartTime;
int rampDown;
int ramplengthpause;
static uint32_t StartUs=micros();
static uint32_t StartMs=millis();
static uint8_t Pwm=0;
//static uint8_t Dir=1;
/// Define pins for ATTiny85 ///
volatile int outPin = 0; // PhysicalPin 5; P0
int ledPin = 1; // PP 6; P1
int pwmMaxPin = 1; // PP 7; P2 Sets Max Ramp hieght.
int ramplengthPin = 2; // PP 3; P4 Sets Ramp length / Mark Time.
int intervalPin = 3; // PP 2; P3 Sets DeadTime inbetween Ramp signals.
///////////////////////////////////////////////////
void setup()
{
/*
Control Register A for Timer/Counter-0 (Timer/Counter-0 is configured using two registers: A and B)
TCCR0A is 8 bits: [COM0A1:COM0A0:COM0B1:COM0B0:unused:unused:WGM01:WGM00]
2<<COM0A0: sets bits COM0A0 and COM0A1, which (in Fast PWM mode) clears OC0A on compare-match, and sets OC0A at BOTTOM
2<<COM0B0: sets bits COM0B0 and COM0B1, which (in Fast PWM mode) clears OC0B on compare-match, and sets OC0B at BOTTOM
3<<WGM00: sets bits WGM00 and WGM01, which (when combined with WGM02 from TCCR0B below) enables Fast PWM mode
*/
TCCR0A = 2<<COM0A0 | 2<<COM0B0 | 3<<WGM00;
/*
Control Register B for Timer/Counter-0 (Timer/Counter-0 is configured using two registers: A and B)
TCCR0B is 8 bits: [FOC0A:FOC0B:unused:unused:WGM02:CS02:CS01:CS00]
0<<WGM02: bit WGM02 remains clear, which (when combined with WGM00 and WGM01 from TCCR0A above) enables Fast PWM mode
1<<CS00: sets bits CS01 (leaving CS01 and CS02 clear), which tells Timer/Counter-0 to not use a prescalar
*/
TCCR0B = 0<<WGM02 | 1<<CS00;
/*
Control Register for Timer/Counter-1 (Timer/Counter-1 is configured with just one register: this one)
TCCR1 is 8 bits: [CTC1:PWM1A:COM1A1:COM1A0:CS13:CS12:CS11:CS10]
0<<PWM1A: bit PWM1A remains clear, which prevents Timer/Counter-1 from using pin OC1A (which is shared with OC0B)
0<<COM1A0: bits COM1A0 and COM1A1 remain clear, which also prevents Timer/Counter-1 from using pin OC1A (see PWM1A above)
1<<CS10: sets bit CS11 which tells Timer/Counter-1 to not use a prescalar
*/
TCCR1 = 0<<PWM1A | 0<<COM1A0 | 1<<CS10;
/*
General Control Register for Timer/Counter-1 (this is for Timer/Counter-1 and is a poorly named register)
GTCCR is 8 bits: [TSM:PWM1B:COM1B1:COM1B0:FOC1B:FOC1A:PSR1:PSR0]
1<<PWM1B: sets bit PWM1B which enables the use of OC1B (since we disabled using OC1A in TCCR1)
2<<COM1B0: sets bit COM1B1 and leaves COM1B0 clear, which (when in PWM mode) clears OC1B on compare-match, and sets at BOTTOM
*/
GTCCR = 1<<PWM1B | 2<<COM1B0;
pinMode(outPin, OUTPUT);
pinMode(ledPin, OUTPUT);
}
//////////////////////////////////////////////////////////
void loop()
{
int static Dir=1;
digitalWrite(outPin,HIGH);
ramplengthpause=(ramplength/3);
if((Dir==-1) && (Dir != +1))
{
digitalWrite(outPin,LOW);
delay(ramplengthpause);
}
/*do
{
digitalWrite(outPin,LOW);
}
while((Dir==-1) && (Dir != +1));
*/
if((micros()-StartUs) >= ramplength)
{
Pwm+=Dir; //increment or decrement PWM depending of sign of Dir
analogWrite(ledPin, Pwm); //Update built-in LED
if(Pwm==pwmMax) Dir=-1; //if PWM reaches the maximum: change direction
if(Pwm==pwmMin)
{
delay(INTERVAL);
Dir=+1; //delay *INTERVAL* & change direction
delayStartTime = micros();
do
{
INTERVAL = map(analogRead(intervalPin),0,1023,800,50000); //800=16ms // adjust all maps according to
pwmMax = map(analogRead(pwmMaxPin),0,1023,100,255); // circuit layout & potentiomenters
ramplength = map(analogRead(ramplengthPin),0,1023,2,11800); // adjust map for packetcount
}
while(micros()-delayStartTime<=INTERVAL);
}
StartUs += ramplength; //loose control of ramplengthPin & pwmMaxPin // only intervalPin works // with int Dir=2; min 4ms
//loose control of ramplengthPin -- pwmMaxPin && intervalPin works // with int static Dir=1;
//StartUs=micros(); //loose control of pwmMaxPin // ramplenghtPin & intervalPin works // with int Dir=2; min 4ms
} // All three work!!!! but....now Triangle wave!!!!! // with int static Dir=1;
}
What am I missing?
What should I try next?
Thanks again for your time.
take care, peace
lost_bro
