ESP8266 Community Forum

- Sun Aug 16, 2015 11:05 am #26177 Howdy Danny,
My electronics knowledge is NOT great ... so it is easily possible that I have an error ... so let's take a look at that part of the circuit. What we see is that with the Reset switch open, REST should be pulled high by R6. When the switch S1 is closed, C1 starts conducting until it is saturated. That brings REST low for a short period of time. Even if the switch maintains closed, once C1 charges, it will stop conducting and REST will go high again. When S1 is opened, R7 discharges the capacitor so that when next S1 is closed, the reset will happen again.

Now ... this is what I built for my environment and it worked ... however, that doesn't mean it is "correct" ... I may have gotten "lucky". Again, I'm not skilled in electronics and discrete components like capacitors and resistors even less (I'm ok with digital as I can just about think of it like a program in hardware).

I have been testing with ESP01 and ESP12s.

What happens if you take a wire and short directly to REST ... does it restart then?

Neil

Free ESP8266 book available for download here.

- Sun Aug 16, 2015 12:03 pm #26185

My electronics knowledge is NOT great ... so it is easily possible that I have an error ... so let's take a look at that part of the circuit.

I'm not that great either.. probably even less

What we see is that with the Reset switch open, REST should be pulled high by R6. When the switch S1 is closed, C1 starts conducting until it is saturated. That brings REST low for a short period of time. Even if the switch maintains closed, once C1 charges, it will stop conducting and REST will go high again. When S1 is opened, R7 discharges the capacitor so that when next S1 is closed, the reset will happen again.

Now ... this is what I built for my environment and it worked ... however, that doesn't mean it is "correct" ... I may have gotten "lucky". Again, I'm not skilled in electronics and discrete components like capacitors and resistors even less (I'm ok with digital as I can just about think of it like a program in hardware).

I have been testing with ESP01 and ESP12s.

What happens if you take a wire and short directly to REST ... does it restart then?

Neil

When I directly connect REST to GND the effect is the same. Weird. For me it's not really a problem (can always disconnect the device) but I was keen to get it to work and add the reset button to my schema.

- Mon Aug 24, 2015 2:36 am #26934 Congratulation for the nice job that you make writing this book!
Thanks for sharing your work.

One suggestion : it could make sense to write about power saving (for the projects running on battery). I mean about deep-sleep, wake up by interrupt, ...

Perhaps also some words about mqtt.

- Wed Aug 26, 2015 4:25 pm #27114 Thanks Michel,
That is exactly the input I need. Will start studying on power modes and MQTT. These have been added into my wish list and will direct what I cover next.

Neil

Free ESP8266 book available for download here.