I'm trying to wake up an ESP-12F from deep sleep mode by pulling the RST pin low for a brief moment (~10ms or less). I thought I needed a monostable (one shot) circuit so I bought an LMC555 timer to take a low pulse and output that as a fixed 10ms low pulse to the RST pin.
Reading and understanding more about the LMC555 timer I realized it may not work for my situation. My wake up signal source could last anywhere from 100ms to several hours (moisture sensor), but I need to generate just a single 10ms pulse and can't have it repeating. I need the ESP-12F to wake up just once, do some work and then go back to sleep. I don't think the LMC555 will work for me because the trigger pulse needs to last for a shorter period of time than the output pulse. So, if I'm looking to generate a 10ms high pulse out the output pin of the LMC555 my trigger pulse needs to be less than 10ms. Unless I'm reading this section of text from the TI datasheet incorrectly "During the timing cycle when the output is high, the further application of a trigger pulse will not effect the circuit so long as the trigger input is returned high at least 10 µs before the end of the timing interval.". In my case the trigger input will NOT be returned to high before the end of the timing interval.
Hopefully, I've explained this properly. To simplify it I'm trying to figure out how to take a low (ground) pulse that could last anywhere from 100ms to several hours and have it generate a single 10ms low pulse. My power source is an 18650 battery which could be anywhere from around 4V to 3.3V. If I can still use the LMC555, great, otherwise I'm back to square one.
How do I generate a regular 10ms pulse with a 555 timer from a Vbat voltage that varies?
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