T1 Mounting & Temp Sensor
The search for the perfect Smart Light switch has led me to the Sonoff T1. There are a lot of things to like about the T1, but the one big knock against it is the style. Let me show you what I’ve done to make the T1 more Wife-Approvable. And as a bonus, I’ll show you how to add a temperature and humidity sensor so you can easily get temperature readings from all over your house.
The Sonoff T1 is a great smart switch. I really like the 3-button version. It gets called 3-gang a lot but I don’t think that’s the proper term. At least according to the wise wizards of electricalness that taught me, a “gang” refers to the width of one switch or receptacle. So this is a single gang, this is a 2 gang, and this is a 3-gang. So technically, this T1 is a single gang switch, but it has 3 buttons and 3 relays. If I worked for Sonoff I’d probably call it the T3. (terminator) but since I don’t work for Sonoff, I can call it whatever I want. I hereby declare it the TriZzwitch!
What’s so great about the Tri-switch? Well, for one it can replace 3 switches. For $20 that’s a great price. Since it fits all 3 switches in a single gang, which is the size of a single switch it frees up a lot of space in the switch box. I’m also a fan of the capacitive touch buttons. But, like most of you, I’m not a fan of this blocky glass cover, or of the weird kinda snap-in box adapter that’s supposed to connect it to your switchbox. Well, here’s my solution. In a 2 or 3 gang switch box you can turn the T1 sideways, and glue it to a blank face plate. The faceplate is thin enough that it still allows activation of the switches. So, it works, it looks good, and it’s cheap. Win, Win, Win.
I expect there will be some folks who are skeptical of using Hot Glue to secure a light switch. Hot glue, if you use enough of it, forms a pretty strong bond. Your switch shouldn’t be getting hot, but even if it does hot glue won’t melt until it gets over 100c. If you want something stronger you could use Liquid Nails, or epoxy glue. It isn’t like we don’t trust different kinds of glue in some pretty important place. So don’t be too quick to dismiss the idea of using glue. At the end of the day, there are no moving parts in this switch box. So once you have it sealed in there, it shouldn’t ever move or come loose. Additionally, to keep the mains voltage separated from everything else in the switch box, I’ve left the plastic housing on the switch. To get it to fit best I had to chop the ends off. But that’s it. Get a blank faceplate, cut the ends off the Tri-switch housing, and glue it to the faceplate.
Getting the circuits connected to the Tri-switch is easy. One Line-in, one Neutral-in and 3 switch legs out. Each of the 3 relays in the Tri-switch is rated for 2 amps. That might seem low, but it’s enough to run a ceiling fan, most of which never exceed 1 amp. And as long as you’re using LED bulbs, most of which are only 6w, you can put up to 20 on one relay and still only be drawing 1 amp. Here’s a little wiring diagram showing how mine is connected now. If you have solid wires, try to bend them before you secure the Tri-switch so they don’t keep applying pressure on your glue joint after you stuff it all in the switch box. I’m reasonably satisfied with the screw terminals on the T1. Better than the Sonoff basic for sure. And that’s it. Looks pretty good. I know it doesn’t solve the problem of putting a T1 in a single gang box. I haven’t cracked that nut yet. But I will!
It’s time for the bonus feature. As you probably know I’ve been replacing my thermostats with my own Smart-o-stats. Well, to get the best and most accurate temperature readings I want to add a few temperature sensors around the house. To my delight, when I tried connecting an AM2302 temp sensor to the Tri-switch it worked! The process is pretty simple. After flashing the T1 with Tasmota. I soldered a header to the Serial PIns. Then I could connect the Temp sensor to 3v, ground, and GPIO3, which is the Rx pin. I had a hard time finding a 3 gang blank faceplate, (at least my local Lowe’s didn’t have them) so I just cut a single gang to add next to the double. Not ideal but serviceable. Either way, you have to cut a hole in the faceplate big enough for the Temp sensor to pop it’s little head through. I sealed it with a little white caulking and Done!
The main point of this video is the install. If you’re comfortable with the software side, including flashing the T1 with Tasmota, and setting up the switches in Home Assistant then you can stop here. If you’ve got a few more minutes and what to see me do the software stuff then stay tuned, here it comes.
The T1’s I have are the newest version, the R2. I really wish they would stop changing the process for getting them into flash mode. At least it is still possible to flash them. I’ll do one the manual way and one over-the-air. My preference is definitely manual. Once it is flashed, you can use the backlog command to load all the settings into Tasmota. If you used the USB/Serial manual flash method then you can use Termite. Or, once the Tri-switch is flashed and connected to your network, you can open the Console and copy and paste the backlog command in there.
You should modify this one and save it somewhere for future flashing:
Backlog SSID1 YourWifiSSID; Password1 YourWifiPW; MqttHost your.mqtt.pi.ip; MqttUser yourMQTTuser; MqttPassword yourMQTTpw
TriZzwitch w/ Temp:
Backlog module 30; PowerRetain 1; SwitchRetain 1; ButtonTopic 1; SetOption8 1; TelePeriod 10; gpio3 02
I’m using Tasmota v6.2.1. You should totally expect that future versions may change some or all of these steps and settings. You’re best resource for all things Tasmota is the Wiki on their github page. If you’re having problems, make sure you read the available information before you post a new issue or ask for help. I don’t want to discourage anyone from asking for help. There are a lot of good people willing to volunteer their time to help you when you’re stuck. Just make sure you’ve done your homework in the documents first. It’ll save everyone a lot of time and trouble.
I’m going to assume everyone watching this is supremely intelligent and is already using Home Assistant. If you are supremely intelligent, but not using Home Assistant yet. Here’s a link to a getting started video. To get the Tri-switch working in Home Assistant you need 3 switch entries in the Switch section in your configuration.yaml file. And the Temp and Humidity sensor entry goes in the Sensors section. Remember, this middle section of all your topics has to match whatever you put in the “Topic” box in Tasmota.
One more thing to show you before we’re done. I want these switches and the temperature to show up in my HA UI aka Lovelace. First I’ll go to the Customize menu and change the icons for a couple of these switches. I can change the name here too if I want, and I do want. Now in the ui-lovelace.yaml I’ll add entries for each light switch, a state-image entry for the fan, so I can make it move when it’s on, and then a state-label for the temperature.
Now we’re done. Even if you don’t use these T1 switches the way I have I hope there was something useful here that’ll help you in your quest for the perfectly smartest light switch.
T1 – https://www.permatrack.us/TriZzwitch
FTDI – https://www.permatrack.us/FTDI
AM2302 – https://www.permatrack.us/Am2302
T1 – https://amzn.to/2yysmcE
FTDI – https://amzn.to/2CD6AHM
AM2302 – https://amzn.to/2EIr5p2