esp -- mqtt -- esp

[wojtulab]

Hello,
i was wondering if it possible to communicate two esp (wemos d1 mini 5v and nodemcu amica 3v) via mqtt broker on RBPI?

My idea:
[esp1] with deep sleep (boots up evry 5min) | relay to FAN awaiting for cmd from [esp2]
[esp2] with deep sleep (boots up evry 1min) | reads temp and humidity then rule: if hum > 60; send $cmd to [RBPI] via MQTT to turn on FAN on [esp1]

my command:
$cmd = /control?cmd=GPIO,2,1


when hum > 60 then:
ESP1 ------> MQTT (running on RBPI)
when ESP2 boots up and read MQTT then will set GPIO on relay to turn on FAN.

Is it possible? How can I setup it with MQTT broker?

For now (bad idea) I have to use:
[esp1] always online
[esp2] with deep sleep (boots up evry 5min) | reads temp and humidity then rule: if hum > 60; send $cmd to [esp1] via HTTP to turn on FAN