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edu001
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Posted: 03:29am 20 Oct 2014

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Hi

I have an odd problem with the PCF8563 RTC on the MicroMite, when I run the test code below which is a simple loop the CPU will only SLEEP on every other cycle ie:

SLEEP miss SLEEP miss SLEEP miss etc

The full code is far more complex but has exactly the same problem, I have tried various pauses FOR NEXT loops DO loops without success

Any ideas ?

'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ''''''''''''''''''''''

Interval = 5 ' sets sleep time (integer value between 1 and 59 inclusive)

Pause 500: ?:? "Entering Loop":?:Pause 500
DO
StartInt

? "SLEEPING"
'
CPU SLEEP
'
? "AWAKE:"

LOOP

' ------------------------ SUBROUTINE -----------------------------------------------
SUB StartInt
I2C OPEN 100,100 ' open an i2c connection with bus speed 100KHz and 100mS timeout
I2C WRITE &H51, 0, 2, &H0F, Interval+1 ' pass Interval time to RTC timer register
I2C WRITE &H51, 0, 2, &H0E, &B10000010 ' Set Minutes OR Seconds: MINUTES=&B10000011 SECONDS=&B10000010
I2C WRITE &H51, 0, 2, &H01, &B00000001 ' reset any triggered flags and start the timer countdown
I2C CLOSE ' close 12c connection
END SUB
'----------------------------------------------------------- -------------------------

atmega8

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Posted: 03:44am 20 Oct 2014

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what stops the sleeping mode?

edu001
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Posted: 03:54am 20 Oct 2014

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atmega8 said what stops the sleeping mode?

Interval is set to 20 secs when time expires INT pin changes state - active LOW (connected to MicroMite WAKEUP pin)

Sorry 5 secs in the test codeEdited by edu001 2014-10-21

WhiteWizzard
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Posted: 06:51am 20 Oct 2014

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I think what you need to do is add a bit of a delay between the RTC waking the MicroMite and before you put it back to sleep.
You may find the Int pin still 'active'. After the line 'Print "AWAKE:" add Pause 500

See how that goes - you may need to 'experiment with the value of the Pause (increase and/or decrease until it works.

Let us know how you get on . . .

edit: The more I think about it, the more I am convinced this is the issue - simple test will prove me wrong (or right

)Edited by WhiteWizzard 2014-10-21

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edu001
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Posted: 07:16am 20 Oct 2014

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WhiteWizzard said I think what you need to do is add a bit of a delay between the RTC waking the MicroMite and before you put it back to sleep.
You may find the Int pin still 'active'. After the line 'Print "AWAKE:" add Pause 500

See how that goes - you may need to 'experiment with the value of the Pause (increase and/or decrease until it works.

Let us know how you get on . . .

edit: The more I think about it, the more I am convinced this is the issue - simple test will prove me wrong (or right

)

I have tried delays everywhere upto 5 secs I get the same thing, I have also tried using I2C Write to stop and start the clock (control/status 1 register)

atmega8

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Posted: 07:25am 20 Oct 2014

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What wakes him up?

He cannot wakeup himself without external help!

edu001
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Posted: 07:28am 20 Oct 2014

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atmega8 said What wakes him up?

He cannot wakeup himself without external help!

Wakes which one up ?

edu001
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Posted: 07:30am 20 Oct 2014

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Ok here s another observation it always ignores the first cycle, I tried to programme a single sleep mode but it cycles twice before it sleeps

edu001
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Posted: 07:31am 20 Oct 2014

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edu001 said

atmega8 said What wakes him up?

He cannot wakeup himself without external help!

Wakes which one up ?

RTC or CPU ?

atmega8

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Posted: 07:40am 20 Oct 2014

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The micromite..

Will the rtc trigger pin 16?

If so, you have external help;-)

edu001
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Posted: 07:48am 20 Oct 2014

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atmega8 said The micromite..

Will the rtc trigger pin 16?

If so, you have external help;-)

The RTC triggers PIN 43 (44 pin micromite) it all works, its a cycling issue, it does not sleep on every cycle

atmega8

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Posted: 08:38am 20 Oct 2014

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Your hardware setup is ok?
Pullups/downs...
Power supply ok?
Test another..

BobD

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Posted: 08:51am 20 Oct 2014

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The Wakeup input on the uMite is edge triggered in either direction.

What is the RTC INT pulse like?
Is it remaining low when triggered or is it a 16 millisecond pulse?
Have you actually measured that pin?

WhiteWizzard
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Posted: 08:55am 20 Oct 2014

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I have recommended that edu001 monitors the RTC Int pin (active low) and waits for it to be at a high level before the SLEEP command is issued.

He is testing this now and carrying out other measurements.

With his findings we can then make our next batch of 'suggestions'

For everything Micromite visit micromite.org

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edu001
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Posted: 09:31am 20 Oct 2014

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atmega8 said Your hardware setup is ok?
Pullups/downs...
Power supply ok?
Test another..

Yes pullups are all ok the power supply is a very clean 3.31v

edu001
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Posted: 09:33am 20 Oct 2014

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Here is the output from the logic analyser

http://imgur.com/iCixP7L

WhiteWizzard
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Posted: 09:39am 20 Oct 2014

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Can you do the test where you pulse a pin immediately before SLEEP and pulse the same pin immediately after SLEEP.
This then allows us to see where the program is at (in relation to the rising edge of the INT pin.

If you can post a zoomed in image so we can see timings and I2C detail then it could help resolve

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edu001
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Posted: 09:59am 20 Oct 2014

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More info 3 images

http://imgur.com/fEaCaPm,zE9DGvA,xns6D4R

edu001
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Posted: 10:08am 20 Oct 2014

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edu001 said More info 3 images

http://imgur.com/fEaCaPm,zE9DGvA,xns6D4R

Missed one http://i.imgur.com/JPZuGMM.png

WhiteWizzard
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Posted: 10:18am 20 Oct 2014

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Brilliant.
Now can you sample 4 cycles (reduce the sleep time to something like 2 seconds) i.e. grab about 10seconds of sample and send the screen shot.

I don't need to see the I2C detail, but as long as I can see the INT pin level and the 'test' pin levels and their relative timings then that would be helpful (Leave I2C connected - will just be 'blips' in the screen grab).

Thanks Jed . . . .

For everything Micromite visit micromite.org

Direct Email: whitewizzard@micromite.o

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