Low Power Sleep

[kduck63]

I am trying to get a 18F2553 to sleep using minimal current until an external interrupt wakes it. I can't get the power consumption down below about 10 mA during sleep. The only other thing in the circuit is a DS1337 and i have disconnected itdurring sleep, but see little current change. I am a beginner at this stuff and based on a search of other posts, I think the configuration fuses are the major part of the problem. Any quick suggestions?

[mackrackit]

Do you have the Watch Dog shut off?

But do not be afraid to post your configs and code. Might make the guessing game go faster...

[Gusse]

If you can share your circuit schematics, that could also reveal some of the reason for high current consumption.
What do you have in OSCCON? Idle or Sleep?

<code><font color="#000000">OSCCON.7 = 0 <font color="#000080"><i>'Device enters Sleep mode on SLEEP instruction</i></font></code>
Some Lessons Learnt from near history :)

BR,
-Gusse-

[kduck63]

The only other device in the circuit is a real time clock; I have disconnected it during the sleep cycle with little or no change. I will try truing off the watch dog timer and setting the OSCCON as suggested.

[Melanie]

Doing that will NOT account for 10mA of Current draw.

Pull your PIC out and measure how much current your circuit still takes without the PIC in place. If it's zero, then the answer is that you must be drawing a shed-load of current through one of your I/O's. The question is which? Pins set to INPUT should take very little current, but those set to OUTPUT may well be Sourcing or Sinking something...

Don't forget to turn OFF ADC's, Voltage References etc... they all take current (but not 10mA worth!!!).