So I have this need to stick some sort of LED next to my external doors that shows alarm state, red if armed, green if not armed. I want it to be very small but also battery powered so I can easily put this ‘status light’ somewhere. I was curious if anyone had any suggestions to do this using ESPHome? I’ve only ever used NodeMCU ESP8266’s and Sonoff S31’s with ESP home but I know there are much smaller boards and I know that LED’s dont take much power so i’m hoping it could be wired up with just a triple A battery or even CR2032’s that last a long time.
The issue with WiFi is that it’s very power hungry. There are lots of fourm posts talking about getting an esp8266 to run for long times, but they normally involve deep sleep with striped components to save power.
I left a esp8266 on a Amazon 5000ma power pack and it lasted a day or so, tho I didn’t do any power tuning.
Hi ideal2545. Sorry, I’m late to this conversation!
Did you have any joy with this using ESP8266?
I’m trying to do something similar. The 8266 sleeps, then wakes every couple of minutes to check if it should have switched on/off the LED.
However, this never even got off the ground for me as the GPIO pins don’t retain their state when it returns to sleep mode, and as cooljimy84 has already shown, the device pulls way too much power to be awake on battery’s permanently.
This is a shame as the 8266 I’ve been playing with only draws 4uA when sleeping, but 60mA when awake.
BTW, GPIO4 & 5 are supposed to remember their state when sleeping, but its not enough current to power an LED.
I’ve read that the ESP32 solves this, but I’ve got a feeling Home Assistant isn’t going to play well trying to switch a lamp on/off whilst this is in sleep mode with any ESP device.
I’ll keep looking for a solution and post back here if I find one.
Adding additional electronics isn’t a solution that I want to do though. Ideally the ESP will handle everything.
Ok, I’ve had an extensive look for an exact solution for ideal2545. The short answer is that I didn’t find one.
There is a solution, but its not an off the shelf solution.
Its possible for an ESP device to send infrared. This could be used to trigger a receiver circuit that could set the state of the LED, either red or green.
nickrout raises a good point that a 20mA draw on (lets say) a couple of AA batteries isn’t going to run for an acceptable amount of time.
The red/green LED would need to pulse, lets say every 2-3 seconds. This would massively extend the batteries.
Christmas LED lights already exist that can be switched off/on etc via an infra-red remote control, so this idea does exist already, example here
Just in case you don’t know, its possible to hook up an infra red receiver and transmitter to ESP devices.
With this, the ESP can learn infra red remote commands, and re-send them.
The whole solution is definitely possible using a PIC microcontroller alongside an ESP, and one I have considered creating as we have various battery operated lights around our home that I would like to be able to switch via Home Assistant.
As always, life gets in the way of our personal/creative time, so I wouldn’t like to promise that I will make this (but I haven’t ruled it out either) !!