Auto Switch off

PhilHornby

Senior Member
HC-12 Standby current

The battery is a PP3, the regulator output drives a HC-12, drawing 75-80 mA.
I missed this at the time, but better late than never...

See this part of the HC-12 thread, wrt putting the HC-12 into low current mode. In a nutshell, it is not sufficient to fire off an "AT+SLEEP" command and assume it worked. It may be ignored completely, or result in a 1.6mA sleep current instead of 22uA.

See Post #82 -> #90 (Page 9) and #96->#97 (Page 10).
 

erco

Senior Member
I did some experiments with SCRs & mosfets, but didn't come up with a bulletproof auto-off solution. I ended up using a low-current reed relay in a 20M2 project, which works great to provide full isolation. I did have some mysterious interference from a too-close dynamic speaker, which caused me a few hours of grief as my deadline approached until I put a ferrous shield in place. Details & pics at http://forums.parallax.com/discussion/167337/canned-ravioli-saves-the-day
 

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