Sonoff 4CH PRO R2

It is always exciting to get something new in the post from Itead and the current postbag includes a Sonoff 4CH PRO R2 unit. This enclosed 4-relay switching unit operates from  5-24v or mains (90-264vac) as required and has four uncommitted outputs with normally-closed and normally open options rated at 30 amps low voltage or 10 amps AC (personally I’d treat that as absolute max for non-inductive loads). The unit is controlled remotely and also has four LED indicators and buttons for local control.


You can use the built-in software which includes support for Itead’s own app (WIFI and 433Mhz remote – remote control not included in the package)  and also featuring various modes and timers as well as working with Amazon Alexa, Google Assistant and Nest. Alternatively you can use open source software, I gave up on writing for Sonoffs as the developer of Tasmota has done such a good job, I could not see the point in re-inventing the wheel).


Construction looks solid and the unit is well-presented.

For those who care about such things, the units have FC, CE and ROHS. No doubt soon after Brexit there will be a British standard to  add to that.

If you need more than one control in any given spot then these units look like a good plan. See also, later article in here on the R3 versions of the 4CH and 4CH Pro


15 thoughts on “Sonoff 4CH PRO R2

  1. new kid on the block i just noticed on YT, the Shelly
    ( )

    solid review find that mains ground is connected to header pins… shame that, seemed like an improvement from the sonoff though not as cheap.

    thinking of how hard it would be to build a solid,safe,small ff prototype, i’m wandering off to why not wired switches in the sockets, with central smart switchboard. signaling possibly through owns mains? would mess up powerline setups but wold there be such tech small enough for wallsockets…

    1. those are supposed to be mounted inside wall mounts, so even so are “safe” as you don’t connect sensors or the like inside a wall mount… look full video, it’s explained

  2. Is there a way to use this unit to switch a 24vac sprinkler solenoid valve? If not with this unit, what other sonoff unit can achieve this, preferably be able to extend to 2 solenoids?

    If you power this unit with 5v, then supply 24vac power to the relays, can the latter accept that power and switch a 24vac solenoid?

    1. Input control power and relay contacts are isolated. Relay contacts are ‘dry contacts’

    2. Not exactly a Sonoff but I’m using the Linksprite board available from Amazon. This has an ESP8266 on board along with 4 or 8 relays. I use the 4 relay version to control solenoids via MQTT and Node Red. Pricing is good.

  3. Theo, author of Tasmota has recently released a raft of updates to his Tasmota firmware. They may be worth a look to anyone who uses sonoff modules.
    Thanks to John of the PUCEBABOON blog for his blog about the updates.

  4. Yes the new R2 is far better than the previous, Mine is due any day. I’m really keen to start messing with it. I saw a wonderful Arduino project where it was as a main 4 channel light fade up fade down unit. Very good looking project. You might like it. The only issue is it uses Triacs so it wasn’t trailing edge dimming thus does not work with many LED lights. Later I found this trailing edge dimmer you might find more interesting to mod your 4 ch R2 sonoff for a very cool fade up or fade down alternative to a light switch. I know you love to mod things so I thought I should share this stuff with you.

  5. Looking at Itead website it appears the only significant difference between this unit and the original version is the change to the range of time delay options in inching mode which seems odd given the nearly 25% uplift in price. The Itead site also implies that the new model is no longer DIN rail mountable. Can you confirm?

      1. Maclej – As does the R1 version – maybe you are mistaking it with the non Pro version

        1. I never did figure out their naming scheme.. Non-pro I guess is equivalent to “amateur”… don’t know why they didn’t just call it version 2.. anyway, a nice boxed unit at a reasonable price.

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