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Topic: Stopwatch with Pause/Lap  6 digit 7 seg LED. HELP! (Read 127811 times) previous topic - next topic

CrossRoads

#30
Dec 29, 2010, 04:58 pm Last Edit: Dec 29, 2010, 07:08 pm by CrossRoads Reason: 1
Hmm, doesn't seem to matter how long I set the interval, with the code as written there is 1mS jitter as to when latchpin goes from High to Low.
The whole time update section & incrementing, rolling over, etc, takes .02mS
The whole shift out sequence only takes 0.8mS.

On to the previousMillis update ...
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

CrossRoads

#31
Dec 29, 2010, 07:00 pm Last Edit: Dec 29, 2010, 07:12 pm by CrossRoads Reason: 1
Okay, I updated the code as follows:
Code: [Select]

unsigned long currentmillis = 0;
unsigned long previousmillis = 0;
unsigned long interval = 10;
unsigned long elapsedmillis = 0;

byte latchpin = 2; // connect to pin 12 on the 74HC595
byte clockpin = 3; // connect to pin 11 on the 74HC595
byte datapin = 4; // connect to pin 14 on the 74HC595
byte testpin5 = 5;

byte ones_seconds = 0;
byte tens_seconds = 0;
byte ones_minutes = 0;
byte tens_minutes = 0;
byte tenths = 0;
byte hundredths= 0;


int segdisp[10] = {
 63,6,91,79,102,109,125,7,127,111 }; //segment references using 74HC595 Shift Registers
//The above numbers light up different segments of a digit

byte time_update = 0;// added new flag
void setup()
{
 pinMode(latchpin, OUTPUT);
 pinMode(clockpin, OUTPUT);
 pinMode(datapin, OUTPUT);
 pinMode(testpin5, OUTPUT);
 Serial.begin(57600);
}

void loop()
{
 currentmillis = millis();  // read the time.
 elapsedmillis = currentmillis - previousmillis;

 if (elapsedmillis >= interval) // 10 milliseconds have gone by
 {
   previousmillis  = previousmillis + elapsedmillis;  // save the time for the next comparison
   time_update = 1;
//    if (elapsedmillis>10){                       // commented this out to display time below
//      Serial.println (ones_seconds,DEC);
//      Serial.println (elapsedmillis,DEC);
//    }
   // digitalWrite (testpin5, LOW); // used to see how long the nex section took
 }
 // else {digitalWrite (testpin5, HIGH);}  // set flag to upate & shift out

 if (time_update == 1){  // no updating if not at 10ms interval, skip this whole section
   // increment the counters, roll as needed, shift the digits out

   time_update = 0; // reset for next pass thru

   hundredths = hundredths +1;

   if (hundredths == 10){
     hundredths = 0;
     tenths = tenths +1;
   }

   if (tenths == 10){
     tenths = 0;
     ones_seconds = ones_seconds +1;
     Serial.print ( tens_minutes,DEC);  // sending minutes/seconds to the screen
     Serial.print (ones_minutes,DEC);
     Serial.print (tens_seconds,DEC);
     Serial.println(ones_seconds,DEC);
   }

   if (ones_seconds == 10){
     ones_seconds = 0;
     tens_seconds = tens_seconds +1;
   }

   if (tens_seconds == 6){
     tens_seconds = 0;
     ones_minutes = ones_minutes +1;
   }

   if (ones_minutes == 10){
     ones_minutes = 0;
     tens_minutes = tens_minutes +1;
   }
   if (tens_minutes == 6){
     tens_minutes = 0;
   }
   // digitalWrite (testpin5, HIGH); // used to see how long the if's were taking
   // counters are all updated now, just do the shiftout one time here:
   digitalWrite(latchpin, LOW); // send the digits down to the shift registers!
   shiftOut(datapin, clockpin, MSBFIRST, segdisp[hundredths]); // print the % first "hundredths" digit
   shiftOut(datapin, clockpin, MSBFIRST, segdisp[tenths]); // print the tens of hundredths digit
   shiftOut(datapin, clockpin, MSBFIRST, segdisp[ones_seconds]); // print the % first "seconds" digit
   shiftOut(datapin, clockpin, MSBFIRST, segdisp[tens_seconds]); // print the tens of seconds digit
   shiftOut(datapin, clockpin, MSBFIRST, segdisp[ones_minutes]); // print the % first "minute" digit
   shiftOut(datapin, clockpin, MSBFIRST, segdisp[tens_minutes]); // print the tens of minutes digit
   digitalWrite(latchpin, HIGH);

 } // end if time to be updated

} // end void loop




am seeing that elapsedmillis = 11 four times a second consistently.
Have it running now, comparing time to my laptop clock, see if they stay in sync together.

Hmm, PC clock not good enough - I get the impression that it drifts a little also, as the two of them don't seem to update once a second together, the display lag between them drifts.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Warren Reeve

I'm running your code above Robert and it seems to be running almost 2 secs slow after 3 minutes..  :-[

I'm running more tests now.

Coding Badly


@Warren Reeve:  Give this a try...

Code: [Select]
unsigned long currentmillis = 0;
unsigned long previousmillis = 0;
unsigned long interval = 10;
unsigned long elapsedmillis = 0;

byte latchpin = 2; // connect to pin 12 on the 74HC595
byte clockpin = 3; // connect to pin 11 on the 74HC595
byte datapin = 4; // connect to pin 14 on the 74HC595
byte testpin5 = 5;

byte ones_seconds = 0;
byte tens_seconds = 0;
byte ones_minutes = 0;
byte tens_minutes = 0;
byte tenths = 0;
byte hundredths= 0;


int segdisp[10] = {
 63,6,91,79,102,109,125,7,127,111 }; //segment references using 74HC595 Shift Registers
//The above numbers light up different segments of a digit

void setup()
{
 pinMode(latchpin, OUTPUT);
 pinMode(clockpin, OUTPUT);
 pinMode(datapin, OUTPUT);
 pinMode(testpin5, OUTPUT);
 Serial.begin(57600);
}

void loop()
{
 currentmillis = millis();  // read the time.
 elapsedmillis = currentmillis - previousmillis;

 while (elapsedmillis >= interval) // 10 milliseconds have gone by
 {
   hundredths = hundredths +1;

   if (hundredths == 10){
     hundredths = 0;
     tenths = tenths +1;
   }

   if (tenths == 10){
     tenths = 0;
     ones_seconds = ones_seconds +1;
     Serial.print ( tens_minutes,DEC);  // sending minutes/seconds to the screen
     Serial.print (ones_minutes,DEC);
     Serial.print (tens_seconds,DEC);
     Serial.println(ones_seconds,DEC);
   }

   if (ones_seconds == 10){
     ones_seconds = 0;
     tens_seconds = tens_seconds +1;
   }

   if (tens_seconds == 6){
     tens_seconds = 0;
     ones_minutes = ones_minutes +1;
   }

   if (ones_minutes == 10){
     ones_minutes = 0;
     tens_minutes = tens_minutes +1;
   }
   if (tens_minutes == 6){
     tens_minutes = 0;
   }
   previousmillis  = previousmillis + interval;  // save the time for the next comparison
 }

 // digitalWrite (testpin5, HIGH); // used to see how long the if's were taking
 // counters are all updated now, just do the shiftout one time here:
 digitalWrite(latchpin, LOW); // send the digits down to the shift registers!
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[hundredths]); // print the % first "hundredths" digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[tenths]); // print the tens of hundredths digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[ones_seconds]); // print the % first "seconds" digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[tens_seconds]); // print the tens of seconds digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[ones_minutes]); // print the % first "minute" digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[tens_minutes]); // print the tens of minutes digit
 digitalWrite(latchpin, HIGH);

} // end void loop

Warren Reeve

Will try it now Codey (thank you).

After more test Robert that was loosing 5 secs after 12 mins..

Warren Reeve

Hi Codey, it wont start?? I changed all my latch pin numbers etc to match mine but it is just showing 00:00:00??  :-/

Code I am using;
Code: [Select]
unsigned long currentmillis = 0;
unsigned long previousmillis = 0;
unsigned long interval = 10;
unsigned long elapsedmillis = 0;

byte latchpin = 8; // connect to pin 12 on the 74HC595
byte clockpin = 12; // connect to pin 11 on the 74HC595
byte datapin = 11; // connect to pin 14 on the 74HC595


byte ones_seconds = 0;
byte tens_seconds = 0;
byte ones_minutes = 0;
byte tens_minutes = 0;
byte tenths = 0;
byte hundredths= 0;


int segdisp[10] = {
 63,6,91,79,102,109,125,7,127,111 }; //segment references using 74HC595 Shift Registers
//The above numbers light up different segments of a digit

void setup()
{
 pinMode(latchpin, OUTPUT);
 pinMode(clockpin, OUTPUT);
 pinMode(datapin, OUTPUT);


}

void loop()
{
 currentmillis = millis();  // read the time.
 elapsedmillis = currentmillis - previousmillis;

 while (elapsedmillis >= interval) // 10 milliseconds have gone by
 {
   hundredths = hundredths +1;

   if (hundredths == 10){
     hundredths = 0;
     tenths = tenths +1;
   }

   if (tenths == 10){
     tenths = 0;
     ones_seconds = ones_seconds +1;
     
   }

   if (ones_seconds == 10){
     ones_seconds = 0;
     tens_seconds = tens_seconds +1;
   }

   if (tens_seconds == 6){
     tens_seconds = 0;
     ones_minutes = ones_minutes +1;
   }

   if (ones_minutes == 10){
     ones_minutes = 0;
     tens_minutes = tens_minutes +1;
   }
   if (tens_minutes == 6){
     tens_minutes = 0;
   }
   previousmillis  = previousmillis + interval;  // save the time for the next comparison
 }

 // counters are all updated now, just do the shiftout one time here:
 digitalWrite(latchpin, LOW); // send the digits down to the shift registers!
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[hundredths]); // print the % first "hundredths" digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[tenths]); // print the tens of hundredths digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[ones_seconds]); // print the % first "seconds" digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[tens_seconds]); // print the tens of seconds digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[ones_minutes]); // print the % first "minute" digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[tens_minutes]); // print the tens of minutes digit
 digitalWrite(latchpin, HIGH);

} // end void loop


Coding Badly


Sorry about that.  Give this one a try...

Code: [Select]
unsigned long currentmillis = 0;
unsigned long previousmillis = 0;
unsigned long interval = 10;

byte latchpin = 8; // connect to pin 12 on the 74HC595
byte clockpin = 12; // connect to pin 11 on the 74HC595
byte datapin = 11; // connect to pin 14 on the 74HC595


byte ones_seconds = 0;
byte tens_seconds = 0;
byte ones_minutes = 0;
byte tens_minutes = 0;
byte tenths = 0;
byte hundredths= 0;


int segdisp[10] = {
 63,6,91,79,102,109,125,7,127,111 }; //segment references using 74HC595 Shift Registers
//The above numbers light up different segments of a digit

void setup()
{
 pinMode(latchpin, OUTPUT);
 pinMode(clockpin, OUTPUT);
 pinMode(datapin, OUTPUT);


}

void loop()
{
 currentmillis = millis();  // read the time.

 while (currentmillis - previousmillis >= interval) // 10 milliseconds have gone by
 {
   hundredths = hundredths +1;

   if (hundredths == 10){
     hundredths = 0;
     tenths = tenths +1;
   }

   if (tenths == 10){
     tenths = 0;
     ones_seconds = ones_seconds +1;

   }

   if (ones_seconds == 10){
     ones_seconds = 0;
     tens_seconds = tens_seconds +1;
   }

   if (tens_seconds == 6){
     tens_seconds = 0;
     ones_minutes = ones_minutes +1;
   }

   if (ones_minutes == 10){
     ones_minutes = 0;
     tens_minutes = tens_minutes +1;
   }
   if (tens_minutes == 6){
     tens_minutes = 0;
   }
   previousmillis  = previousmillis + interval;  // save the time for the next comparison
 }

 // counters are all updated now, just do the shiftout one time here:
 digitalWrite(latchpin, LOW); // send the digits down to the shift registers!
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[hundredths]); // print the % first "hundredths" digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[tenths]); // print the tens of hundredths digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[ones_seconds]); // print the % first "seconds" digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[tens_seconds]); // print the tens of seconds digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[ones_minutes]); // print the % first "minute" digit
 shiftOut(datapin, clockpin, MSBFIRST, segdisp[tens_minutes]); // print the tens of minutes digit
 digitalWrite(latchpin, HIGH);

} // end void loop

Warren Reeve

Quote

Sorry about that.  Give this one a try...

Lol.. no worries. Ok, that 1 is running.. I will report back in 10 mins or so and see what it's like..  :)

Warren Reeve

#38
Dec 30, 2010, 12:29 am Last Edit: Dec 30, 2010, 12:36 am by warrenreeve Reason: 1
Hi Codey,
After 17 minutes it is just over 3 seconds slow..??

After 25mins it reads = 4.66 secs slow?? Approx

Coding Badly


There are two possibilities left...

1. Whatever you are using for comparison is not accurate.  What are you using?  Have you tried something else?

2. The board you are using has a resonator or oscillator instead of a crystal.  What board are you using?

Warren Reeve

Hi Codey, yes I have tried that.. I was originally timing it from my mobile phone but after all the controversy I though it would be a good idea to double/treble check how accurate it was.
I checked my mobile phone against my PC and it was accurate to it and then I checked the both of them against a hand held stopwatch/lap timer.. all 3 ran the same speed. My arduino is approx 4 weeks old and is an Arduino Uno.

Hope that helps.  :-/

Coding Badly

#41
Dec 30, 2010, 12:59 am Last Edit: Dec 30, 2010, 01:00 am by bcook Reason: 1

I believe that the Uno has a resonator and... (4.66 / (25 * 60)) * 100 = 0.31 % ...is about the typical accuracy for a resonator.

But, you should have someone else confirm what I'm saying.

I also suggest you try to get a few other Uno users to confirm what you're seeing.  The shiftOut calls can be replaced with Serial.print calls.

Warren Reeve

Code: [Select]
if (ones_seconds == 10){
     ones_seconds = 0;
     [glow]hundredths = hundredths +7;[/glow]   // Speed up the clock!
       tens_seconds = tens_seconds +1;
   }


Would this be acceptable as a fix? (shown previously)
Basically, if the Uno is out a little would it not be ok to give it a little back each loop? I don't want to bad code or anything like that but if the internal time is not accurate I don't see much choice in this situation.
Also please keep in mind that I am a complete novice with all this.  :P

PS. Time difference after 1 hour = 11 seconds.  :-[

Coding Badly

Quote
Would this be acceptable as a fix? (shown previously)

Only you can decide.  If what you are trying to build is "for entertainment purposes" then I can't imagine a little tweak being a problem.  If money or pride is involved, you may end up involved in some heated arguments (or fights).

Quote
Basically, if the Uno is out a little would it not be ok to give it a little back each loop?

Certainly.  But you should first confirm that your Arduino really does have a resonator instead of a crystal.

Warren Reeve

Yes, I agree.. lap times can become a very heated conversation at times.. I would certainly not like to be the guy who made the racer go slower...!!! >:(  haha.. then you would see some fast laps as I left the building!! Lol.
Quote
But you should first confirm that your Arduino really does have a resonator instead of a crystal.

If anyone reading this can shed any light on this.. please do otherwise I will try and get an answer from Arduino or someone else as soon as I can.
Thanx again to Robert and Codey for all your time and help. Really appreciated.  :)

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