Sonoff 4CH Pro Review

I received a Sonoff 4CH Pro the other day and have had a fun time playing with it. It is similar to the original Sonoff 4CH in the number of outputs that it supports, but differs in the fact that the relays are dry contact relays. This of course means that varying types of devices can be connected to the relay as each channel essentially has an input and output power terminal.

There are limitations on what the device supports. Itead advertises the voltage range as 90-250v AC(50/60Hz) / 5-24v DC and the max power as 10A/channel. This should be able to cover a wide range of projects and uses out there.


The device has three modes configurable by jumper switches underneath the Sonoff 4CH’s case. The first is “Self Locking”. I would consider this mode to be “standard” even though mine did not come shipped this way. In this configuration, the device will turn a channel on when one of its buttons is pressed and turn off the same channel when the button is pressed again. All channels can be turned on or off without affecting any of the other channels.

The next mode is “Interlock”. In this mode, only one channel will be on at a time. Pressing the button for channel one turns it on and then pressing the button for channel two will turn off channel one while channel two is at the same time activated.

The last mode is “Inching”. Similar to a “momentary” mode this essentially puts each channel activation on a timer. The timer is configurable with the jumper switches and can be as large as 4 seconds. The idea is that once you release the button for the channel, it will stay on until the timer for that channel expires. So, if the timer is set very low, it works as a traditional momentary button. It will stay on until you release the button. Set it a little longer (for the full four seconds for example) and it behaves a little differently.


Along with the features mentioned above, the Pro also has some added functionality. It supports DIN mounting, an RF remote, as well as Alexa. Unfortunately, I have not had a chance to test these three things, but Alexa has worked well with Itead’s other products.

I was able to test some of the features of the EWeLink app. This app is the default way that users can control Itead’s line of devices from their Smartphones. Now, I love the Sonoff devices because they allow you to flash them with custom firmware, but at the time of writing I have not yet been able to flash the Pro with alternate software.

Having said that, the EWeLink app works great for controlling this device. You can control the Sonoff 4CH Pro as well as set timers and schedules for each channel. I didn’t have any problems with it and found it to be quite reliable.

A standout feature of the device is its ability to save the timers and schedules locally. This is great for those that have a “not so reliable” internet connection or just don’t want to rely on the cloud for their device to trigger when it is supposed to.


Overall, this is another great Sonoff device provided by Itead. There are a lot of possibilities for the Sonoff 4CH Pro and I am excited to see what kind of projects become of it. Although the custom firmware support for it isn’t there yet, it can stand on it’s own with what the EWeLink app provides. Having said that, I will definitely revisit the device once the esp8266 community (including myself) discover the intricacies of how it works.

Where to Buy

It just so happens that Itead is having a promotional sale on their products. Click through to this link to get some great smart home gear at up to 20 – 30 % off!

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