Review: Sonoff 433 RF WiFi bridge
By @edent
· gadget IoT review Smart Home sonoff sponsored tech · 29 comments · 450 words · read ~11,309 times.
The good folk at Sonoff have sent me yet another gadget to review. This is a slightly curious device - an IP to 433MHz remote. This allows a smartphone to control smarthome gadgets which usually require an RF remote control.
It costs £8 plus postage direct from Itead.
This is similar to an Infrared device I reviewed a few years ago.
It's a cute little box, small and light enough to hide away anywhere. Even under use, it doesn't get hot.
Note - it only connects to 2.4GHz WiFi. That's standard for these cheap gadgets.
Powered by the ubiquitous micro-USB, it comes with a short cable, but no plug socket. I assume you have plenty at home.
Blinken lights! Little status LEDs so you know what's going on.
Software
You need to use the eWeLink app. Like lots of smarthome apps from China, it isn't the prettiest - but it works. The translations on the app and the user guide would benefit from a more professional approach, but it is adequate.
The app is quick to respond - but I found that it would occasionally log me out, and I'd have to re-enter my password to continue.
It also supports Amazon Alexa! Incredible for a device this cheap. As I mentioned in my previous review, setting up the eWeLink Alexa skill is a bit cumbersome - but it works!
Buttons!
You also get a keyfob with four buttons on it. 
It is an RF remote which you can pair with the box. Kinda neat if you don't want to unlock your phone to activate something.
Usage
It works - but there's a catch - how many 433MHz devices do you have? I had to dig out some old demo kit in order to play with this gadget. If you've got compatible devices, this is a useful gizmo - but most modern devices have WiFi built in, so it may be worth upgrading older devices if you can.
If you have devices which need 433MHz controls, this is a ridiculously cheap way to add them to your home network. The Alexa control is the icing on the cake.
Teardown
It isn't a review if you don't get to see the guts :-)
The retail model I've got has populated debug headers and an internal on/off switch.
Nice and neat design. I'm told that it should be fairly easy to flash and dump the firmware. For those who care about such things, the main chip is the ESP8285.
Get It
- You can find out more information on Sonoff's website
- Full specification - including schematic - is on the Itead Wiki
- Finally, you can buy it for £8 (US$10) from Itead directly
Alex says:
LightwaveRF switches use 433MHz so this might work as a cheap replacement for their £60 bridge (which I'm not very impressed with). Did you find out how many devices it can control?
Terence Eden says:
The manufacturer days "16 at most". If you have more than that, you should be able to use multiple bridges.
MI says:
It can only add four RF Remotes, so if we add four 4-button RF Remotes(each button learn with one RF device), we can control maximum 16 RF devices. But for others, like RF Alarm, RF Curtain Switch, they are counted as one RF Remote.
Thanks for the review of this. I was very curious when I saw it!
Any idea why there's a limit to the number of items it can control? Does the device "learn" from other RF transmitters, and only have 16 memory slots? I was hoping it would be like a wi-fi version of the RFXtrx433, which will send any message you program it to, at any time.
On that subject, if it does learn, is there an option for repeat signals (i.e. keeping your finger on the remote)?
Thirdly, what's the additional keyfob for? Given this device is a transmitter, I don't get the point of this!
I use LightwaveRF devices with the RFXtrx433. And I use the openHAB binding to tie it all together. It's a really nice, cheap, and flexible way of retro-fitting dimmer switches to the home. Well, LWRF used to be cheap (20 quid for a double dimmer), not sure if it's still rock-bottom low price like that. Wouldn't choose this method if wiring a building from scratch, but it's a good low-investment way of getting smart dimming into the home.
Justin says:
It Tx and Rx. You can essentially map buttons to functions (rx this, tx that). But it's very much stuck in the RF world, at least with the built-in-software.
Off-topic: what did you have to cover up with a white circle in the last image?
Terence Eden says:
That's a secret ?
I was just curious about what to keep in mind when uploading photos. Internet security, etc. 🙂
Andrei Panferov says:
Tell me, is it planned to increase the ranges of operating frequencies. 433.92 is no longer programmed.
@edent says:
You need to contact the manufacturer directly.
Robin says:
Hi could you mention how you remove the plastic casing? Cheers
@edent says:
Brute force and a spludger.
david says:
What do you mean by the “RF Curtain switch” ? This would seem to indicate that the device can “transmit” 433 Mhz signal codes and not just receive ( sense ) them.
How else would you control a curtain if you didn`t transmit a signal ?
Great device, I have 4 and am getting 2 more, but I want to now transmit signals to control other devices which accept ( receive ) 433 Mhz RF signals.
Thanks
Kevin says:
If I have RF on/off switches that use different codes for on and off, would I be able to control 16 different switches or just 8 (8 X On + 8 X Off)? Does that make sense?
@edent says:
I don't know. I suggest trying and reporting back.
rondoc says:
I need a reverse bridge. One that takes rf from a remote push button and connects to my wifi and via the cloud connects to a wifi only switch. I bought a load of the wifi switches but in some places I don’t have a smart phone so would like to use a 4 button remote. I thought the bridge you mention fid that but it is backwards from what I need or did I miss something?
Graham Horn says:
You didn't miss anything. It doesn't work the other way round unfortunately. I too wish it did. Some aspects of Sonoff are good, but it's by no means the most versatile product around.
Justin says:
I don’t get why these bridges are sold/seen as a way to (primarily) control RF devices from the IP network, rather than the other way around,
i.e. Given that RF transmitting switches/fobs etc are so incredibly cheap, and the batteries last forever, a way to bridge RF switch/button pushes (from any 433MHz tx) into Google Home or proper HA commands would allow wall switches and portable remotes anywhere and everywhere they might be useful.
I thought that’s what I was going to get with my Sonoff bridge, but unfortunately it wants to receive instructions from Google Home, not provide them to Google. Alexa, Philips, or anything else as far as I can make out.
Mike says:
I got my Sonoff RF connected to my phone and also got my autogate remote link to the Sonoff RF. The problem is that when I want to open/close the gate using my phone it sends the signal to the Sonoff RF box (red light on) but the automate does not open or close.
Juan Carlos Martinez says:
Any idea of maximum distance the controlled rf device can be separated from this bridge?
It worked across my house - but it isn't that big. Sorry I can't be more specific.
Juan Carlos Martinez says:
@edent that would have been how many meters? Thanks,
JC
About 6 - but with walls in the way. Again, you'll need to test it yourself.
Juan Carlos Martinez says:
Many thks
Graham Horn says:
The RF range is very poor. I have tested two of these and they don't work 100% reliably even 2 meters away in line of sight.
Greg says:
I was looking at the sonoff T1 light switches until I found that it requires a negative line going to the switch so have looked at the Sonoff T433 86 RF switch instead. Am I right in thinking, I can use the T433 with a sonoff RF or sonoff Slampher without a bridge, but if I want to use it with the App on my phone, to set scenes etc I would then need an rf bridge?
Jojo Ferrer says:
I installed two sonoff slamphers and are controlled by RF remotes as well as thru the eWelink app. I have a 3 gang RF controlled touch switch. in which I also control it with an RF remote fob, these switches have two wiring connections: live and neutral or ground. I'm planning to buy an RF bridge and am going to try if my touch switch will work with this. If it does and hopefully I will be able to control my living room light thru the RF Bridge. My devices are mostly sonoff except the smart power strip (Smartlife) and a single gang smart plug Broadlink). What I like abut their product is that most of their devices can be controlled thru LAN if your connection goes offline and most of their plugs operate this way as well as their slamphers. I also like their 4CH and smart switches (in which I own both) especially their RF version in which you can control it by RF remote fob.
Rick says:
I’m confused about this device.
I have a bunch of wifi “SmartLife” devices. Some are switches, some are bulbs, some are outlets. I have a bunch of automations in SmartLife and Alexa integration.
I’d like to add some 433 remote controls.
Will this allow SmartLife to see the “bridge”? Will it somehow make a 433 remote appear as a wifi SmartLife remote?
Does it work in “reverse” and allow SmartLife to control 433 devices?
@edent says:
I think it does both. You can send 433 commands from it, and you can listen for a 433 remote.
This blog post is 4 years old, and I don't have any 433 devices to test it with. But it is a cheap bit of kit, so perhaps worth you buying & blogging about it?