Save energy while system is not working

moreet

Hi everyone,

I realized a meteo station that sends meteo data when a valid DMTF from VHF reachs it.
The MT8870 brings high a pin when a valid tone is detected.

How could you use the NAP command to save energy?
Thanks again.

m.

Mike Green

There is a good description of the NAP statement in the BASIC Syntax and Reference Manual along with an example of its use. Also look at the chapter on the SLEEP statement in the same Manual. You can download the Manual from Parallax's Download webpages. I believe it is included with the Stamp Editor's help files.

Tracy Allen

How long is the pulse from the MT8870? If it is very short, you may have to make a way to stretch it using a latch or a capacitor. The pulse has to last long enough to be detected after the NAP. The NAP interval can be set from 18 milliseconds (NAP 0) to 2 seconds (NAP 7). The Stamp wakes up after that interval and would check the input and would either goe back to NAP or wake up to handle the data transmission when called for. The best power savings comes with a longer NAP, and thus the question about how length of the pulse from the MT8870.

The task is easier and the power savings much better if you use the BS2pe. The BS2pe has the POLLWAIT command, which is like a NAP command but the testing of the input pin is automatic. The power savings is greater because the BS2pe wastes very little power when it wakes up temporarily to check status.

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Tracy Allen
www.emesystems.com

moreet

Thanks Mike, thanks Tracy.

I figure to buy a BS2pe and use the poolwait command.