Am I missing something? Neither schematics nor my limited understanding of physics explains why you need to, nor how it is possible to, bend one of the pins to disconnect GPIO0 (chip-row, 3rd from the left) from the reset pin (edge-row, 2nd from the left)... Is it me? Have I been misusing my 8266s all this time? Otherwise, good article, nice idea, great conclusion!
“This relay module board for the ESP-01(S), It comes pre-soldered, and the ESP will just slide on top of it.”
So, bending that pin breaks a connection between the CPU board and the relais board, so that pressing the doorbell wouldn’t be able to send a reset signal to the CPU, or, as the article says:
FTA: “Without this modification, a doorbell button push would result in a reset/restart of the chip, which of course, isn’t what we want”
That made me wonder why the hardware is hooked up that way by default in a device that gets sold for this specific purpose.
A few searches learnt me that the device has a deep sleep state where it uses very little power. The only way to wake it up externally from that state is through a reset.
https://johnmu.com/quick-boot-button/ taught me that it can boot in about 100ms, and get WiFi on in a few seconds.
=> I think that keeping that pin in place is the intended way to use this hardware combo.
The device would boot when the bell is rung, first close the relais switch to ring the bell, and then do any home automation stuff a few seconds later. Latencies look acceptable to me.
I ideally would want to power it completely from the button push or, at least, from the same adapter as the doorbell, but both will be challenging. The first doesn’t deliver enough power for long enough, the second likely doesn’t run on 3.3V.
