This is the first experiences I had with the RFXtrx433E USB 433.92MHz Transceiver. I upgraded a few days ago from Tellstick Duo, and I don't regret it.
After a few days with the 433MHz RFXCOM transceiver I must say this little box is quite outstanding. At first I tried to connect it trough at USB hub. I also connected it to a long USB extension cable to place it, where I thought, was a good spot. Time for a range test.
I have 3 DIY PIR sensors I made from Arduino Pro Minis (3V) running in the kitchen, livingroom and bedroom. I also have a Nexa door magnet (LMST-606) on the front door. One of the PIR sensors is behind the fireplace brick wall +one wood wall to reach the RFXCOM transceiver. The magnet sensor on the door had almost free sight to the RFXCOM unit about 8 meters away.
The reception was non existent... This was NOT the way to do it. What to bear in mind is that the RFXCOM transceiver is less sensitive if you have a lot of receiver protocols enabled. I disabled every receiver protocol, except X10, AC and ARC.
I then connected the RFXCOM directly in one of the Raspberry Pi's USB ports, without an extension cable. After that, everything worked as it should. I then prototyped a X10 security transmitter with an Arduino Pro Mini and a cheap 433MHz transmitter. This runs on 3V. The prototype transmitted an "Alert" every 2 minutes. I wanted to test the range. In DomotiGa I could see the signal level in the log as things happen. In the same room (office) as the RFXCOM transceiver, the signal level was 7. I assume that this is the highest level.
I then moved the prototype down to the basement. That's one floor down and a couple of wood walls away from the RFXCOM transceiver. The signal level was 6. I saw I still had a lot to go on. The next step was to move the transmitter out to the shed, about 20 meters (65 ft) away from the house wall. The transmitter had to reach trough 4 wood walls in addition to the 20 meters over the front yard. I got an amazing signal level 4 and 5 from that distance!
Now I plan to build the prototype in a box and place it around the neighborhood to see how far I can stretch it. The RFXCOM transceiver far exceeded my expectations, and it is already capable of covering the whole area I need it for.
The transmitter don't have the sensitivity issue, obviously. I have 4 Nexa socket receivers in the room next door to the RFXCOM transceiver, and they work just fine. I have not tested any range on these yet. I'll come back with more as soon as I have tested the transmitter range.
Here is a "rule list" to get the most out of the RFXCOM transceiver:
- Disable all receiver protocols you don't need
- Do NOT connect it to a USB hub
- Do NOT use an USB extension cable
- Place it fairly high up from the floor
You may want to read how I finally increased the range of the RFXCOM transceiver.
And feel free to give some feedback in the comments below and tell me about your own experiences.