I am planning to make a wlan remote control (not infrared, bluetooth or otherwise ISM technology). Most of the work is actually done (the software part) and it does already work, as long as it's connected to a power line. And that's the issue, for it to be really usefull, it will need to run on batteries.
I am lucky I have the space for one or two penlight batteries, no need to go for coin cells. But even then, 1.2 Volts or 2.4 Volts (1 or 2 rechargable batteries) is too low or very quickly too low for the ESP8266 to run on.
So I tried one of my always "in stock" boost converters (containing an XL6009). That won't work though, because officially it needs 5 V to run on (although I could see it starting to work from 2.6 V). I now have ordered for a few other boost converters, that are supposed to start working from 0.9 V, I'm very curious if they really work well, we'll have to see.
Now the interesting part, the power management. I had the following in mind. There are six inputs for user control (two encoders each with an A, B and toggle outputs). All of them need to be able to wake the ESP. As far as I know both A and B signals are low when idle, will check. Toggle is also low on idle. So what I need to do is make a logical or for all those signals, make it start a timer and while the timer is running, it should pull the chip enable pin.
Now the, I think, most interesting decision is how to keep the ESP active long enough for it to be able to process the input, send it and keep around for long enough to give the user a smooth experience. I could configure the timer to keep active for about one minute, but there is also another approach, where the timer is only active long enough for the ESP to boot, then the ESP would keep itself powered on for a configured amount of time. I would prefer that last option. It would allow for a proper deassociation from the access point instead of simply turning of the power. I think it will need another "or" between an output pin and the timer.
For the "OR" ports I actually was thinking of an 2 times 4-in-package 7400 type OR, CMOS compatible and low power, something like the AC type or newer. I don't like "wired" OR (which would be very simple of course). And for the timer the old 555. I am not sure both can do what I want, I am still investigating.
Any thoughts on this?