Daikin remote control

I have a couple of Daikin units I would like to automate. I could buy Daikin WiFi extensions, but they are quite expensive and my units lack the S20 socket, so I would also need an adapter, so I opted for DIY devices using the ESPHome IR remote climate component. Looking around the web it seems that everybody have devices externally powered, instead I would like to keep them inside the Daikin units. My idea is to buy a couple of Sonoff Mini R2, flash them with ESPHome custom firmware and use the extra GPIOs, like GPIO0 and GPIO2, +5V and GND soldering some wires on the PCB:

Connecting at least an IR transmitter (and optionally a receiver too) placing the led between the IR window and the IR receiver inside the Daikin unit.

I would really like power the Sonoff Mini R2 from the Daikin unit itself (which in turn is powered from the external unit) from pins 1, 2 and ground.

Do you think it is a good idea? Why everybody is powering IR transmitter from outside power sources?
Thank you!

Assuming that you know how to work safely with mains power , I think it’s an elegant solution to use a Sonoff device that has a built-in power supply. One thing you need to worry about is that the IR transmitter board may be referenced to mains voltage, so you have to make sure it’s properly isolated so no one can even touch it (yourself, family members or perhaps an HVAC technician). That antenna also looks like a prime candidate of not being mains-safe.

I haven’t look extensively, but other solutions use 5V/3.3V boards like a Wemos D1 Mini, for which you would need a separate power supply anyway, and building one (instead of using a simple USB charger) may be a bridge too far for many people.

Thanks for your advices. I’m not an expert but I think I will be able to switch off in the main electric panel the HVAC system before doing the work. The external antenna is not present anymore in R2 version, replaced by an internal one printed on PCB. I can also remove my device if a tecnichan need to access the unit, otherwise, being everything inside the unit should be safe enough. I have to dig some more to check the +5v line safety. It is from the top-left side of the PCB which seems the low voltage part of the circuit, w.r.t. the bottom-right with high voltage components. Thank you for your help!

The PCB doesn’t seem to have an isolating transformer, which means that it’s likely that even the low-voltage part of the PCB may be referenced to mains (that’s also probably the reason they removed the external antenna).

In other words, it will not be safe to touch any parts of either the device or the IR transmitter, even if they are only connected to the low-voltage part of the PCB.

@robertklep, perfectly clear. Everything will be closed inside the unit, so nobody will be able to touch it. I can also add a piece of heat shrink tubing over the IR small PCB. I will put warning labels also on the sonoff and IR unit too. Thanks.

Instead of going through the hassle of DIY I am using those inexpensive Broadlink/Bestcon RM4 mini for exactly the same purpose with our Daikin AC’s. Together with Broadlink’s HTS2 Humidity Temperature Sensor-cables I control the AC units through SmartIR which comes with preset codes for many different Daikin AC’s.

The Broadlink gear is hidden behind the cover of the indoor units connected to the AC power. Thus the whole thing is completely invisible from the outside.

As for the HA Dashboard I have installed Simple Thermostat and it looks like i.e.

Cost per AC unit per set: ~USD 20 compared to ~USD 300 (here) for the original Daikin WiFi extensions.

All is working very reliable with quite a few automations in place since ~2 years now without any hiccups.

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Not sure my unit can hide both the broadlink RM4 mini and the power adapter, but I will check. Using a commercial product would be the safest option.

I am using a USB adapter plug connected to a Euro coupling for it. Fits well between the pipings to/from the evaporator.


(Sorry, I forgot to put the above into the price tag with my first post)

I am new to smart home and HA and want go down this route but am slightly confused as to why you need the HTS2, you mention that you place it inside the AC unit in which case how do you get a good room temperature reading from it? also how do you place the the RM4 inside the unit and make sure it triggers the unit’s IR receiver? can you share a picture?
Many thanks