433 MHz technology in smart home and domotics

433 MHz is a term that you might have encountered within smart home and home automation. So what is it, and what does it do? 433 MHz is a wireless radio band. It’s a frequency on which household devices are allowed to send signals. A lot of companies use 433 MHz to make products that have a remote control. Examples are motorized blinds from Somfy, or socket switches from LightwaveRF, Cleverio, Nexa and Telldus.

TVs often use infrared for remote control. 433 MHz on the other hand is used by companies to control socket switches, motorized roller blinds, wireless sensors and all other sort of equipment. 433 MHz technology has been around for a long time, and is embedded in lots of wireless devices. That’s why it’s one of the six wireless technologies in Homey.

Pros and Cons of 433 MHz technology

433 MHz has been around for a long time. It’s fairly simple to include in products. It’s also very cheap to do so. That is why devices using 433MHz as wireless technology are often attractively priced, like 433MHz-based socket switches.

Compared to infrared, it has one big advantage as a remote-control technology: it can go through walls, as it’s a radio technology, and not a flickering light. For a TV this is not really needed, but you can imagine that for remote control of that wall plug behind the sofa, your motorized roller blinds or for home automation purposes, this is a big advantage.

Overall range is the biggest advantage of 433 MHz technology. The frequency is quite low compared to other technologies like Z-Wave (868-928 MHz), Zigbee (2.4 GHz) or Wi-Fi (2.4 or 5.8 GHz). This means it can hold less information, but is better able to move through walls. Hence, the point-to-point range 433 MHz devices can reach can be quite impressive. This is especially the case when a 433 MHz hub like Homey sends a command to a device like a motorized blind, in which case the signal can travel over 100 meter (300 feet).

Power consumption of devices on this technology is also fairly low, and comparable to other dedicated home automation technologies like Z-Wave or Zigbee. This makes 433MHz also suited for battery-operated devices like wireless sensors or buttons.

Disadvantages

The history of 433 MHz brings good things like ease of implementation and price, but it also has its downsides. The technology itself is very rudimentary. Signals are typically only one-way. This means a device only sends, or receives. It also means that commands that are being given are not confirmed by the receiver. We just have to assume the command has been picked up and is being executed. This makes 433 MHz devices, and especially sensors, less reliable than their counterparts on Zigbee or Z-Wave.

Next to that, 433MHz devices don’t build a ‘mesh network’. Mesh networking is a great technology that allows devices to relay signals meant for others in the network. It essentially extends the range of your devices as long as there are others on the same technology in between. The range and reliability of your devices actually improves when more devices are added. 433 MHz devices do not have this capability, while Zigbee and Z-Wave devices do, making the latter two more reliable again.

The information sent is also quite limited. 433MHz usually have limited bandwidth. As such, they only support a couple of commands. For instance, your roller blind might not even be able to move to a set percentage, but only has up, down and stop. Battery information is also barely given, nor is energy consumption information. Despite the fact that 433MHz devices can be battery-powered, there is often no low-battery warning, so you’ll have to keep an eye on that yourself.

Lastly, you cannot connect 433MHz devices directly to your phone. Your phone does not feature a 433 MHz antenna. So you always need a smart home hub to connect with these devices, and to automate them. This is however the same with more premium technologies like Zigbee and Z-Wave. Luckily, Homey includes 433MHz, so if you have Homey you have nothing to worry about.

Conclusion

To sum up, 433MHz devices are often quite basic devices. They are priced attractively and have a good point-to-point range. On the other hand, their command set is limited, they do not give battery warnings and the one-way communication makes devices (mostly sensors) on this technology less reliable than these on Zigbee or Z-Wave wireless technologies.

A lot of popular brands use 433 MHz as it has been around for a long time and can be added to products fairly easily. Brands like Somfy, Sunway, LightwaveRF, Nexa, Telldus and Trust Smart Home all use the technology for their attractively-priced products.

Home automation on 433 MHz is very cost-effective. However, don’t expect the best of the best. For simple socket switches without power measurement or motorized shades and roller blinds, 433Mhz is a good choice. For lighting, sensors and security there are definitely better options. That is why we recommend to combine 433MHz automation with another technologies like Z-Wave or Zigbee if you want to fully automate your home.

Getting started with 433 MHz home automation

Building a 433MHz setup is quite easy. As it is a wireless technology, there’s obviously no wires to install. And because most devices are quite cheap and easy to get, you might even have a set of plugs lying around already. To get started, you just need Homey and a supported device on 433MHz. Pair your device to Homey and you’re good to go.

Now, 433MHz is a fine and affordable technology, but not the whole world runs on it. There are several other wireless technologies out there powering Smart Home. That is why we recommend to stay versatile with Homey. Homey is not only a 433MHz gateway, but can also control devices on your Wi-Fi, and via Bluetooth, Infrared, Z-Wave and Zigbee signals. All these technologies may not mean much to you, but together they are all the ways to wirelessly control devices. And with Homey, you can connect them all.