TASMOTA 3 Way Smart Switch by Martin Jerry | ESP8266 2.4G WiFi, Smart Light Switch for Home Assistant | Smart Home Devices

I've been doing home automation for about 3 years. I spent a whole saturday wiring up a 3-way switch with a Shelly. I am kicking myself for how much time I wasted on other solutions. If you can install ANY light switch, you can install this switch. This Martin Jerry switch was super easy to install.There is a noticeable lag between pressing the switch and when the light turns on. I mean, it's almost instant, but it's not instant. Likewise I think the fit and finish on these looks a little cheap. They don't look upscale or fancy.Having said all that, if you're an amateur and you're just getting started, the whole Martin Jerry line is the easiest thing I have ever used. Tasmota puts YOU in control, and Martin Jerry is doing the hard part for you: putting Tasmota on the device before you get it.

I have flashed most of my switches for Home Assistant and having one that is pre-loaded, at a price that is similar to generic ones is great. Instructions were clear, and the follow up by the company is over and above.

Easy to install, and config. There's more work to configuring it, because it talks to my Home Assistant server over MQTT, but not hard.They are very reactive. I replaced some Meross with these, because the Meross kept loosing connection. These have never had that problem.My only complaint is that I can't configure it to do night light mode. So the LED in the sitch is on, when the light is on, and off when the light is off. I want it the other way around, so you can see where the switch is, in the dark. If the switch is in the same room as the light, then it doesn't make sense to light it up, letting me know it's on.However for the one for the garage, it's great. The switch is in the house, and I can see from downt he hall if my garage light is on. Make sure to turn it off on my way to bed.

This 3 way switch has feedback to know when the output is on or off. This sounds like an "of course it should" until you start thinking about how to actually implement it electrically. I was expecting just a dumb relay output but no, this is a proper smart device with feedback. It can be wired at either end of the 3 way chain, either at the beginning with the common being the unswitched feed or at the end where the common feeds the load. Yes, it will power off the travelers. It also detects whether the device is on or off in either configuration. This appears to be a voltage based detection, it relies on the load pulling the output low to detect power state. If there is no load it sticks in a "on" state. Which might be a problem, but also means this can indirectly tell when there is a open circuit or a burned out bulb: If the power state is commanded to toggle but the detected state doesn't then there is a fault.This is a TuyaMCU based implementation, so there is a Tyua chip in here doing the actual device IO. This also means the switch is responsive, as the ESP MCU is not in the mix. It has a green LED that lights up when the output is on, driven by the TuyaMCU. Unfortunately that means reprogramming the IO isn't as easy as adding a new Tasmota Template, but if that's the worst downfall I'll take it. If the load is open circuit the green LED in the unit sticks on.I did disassemble this and take a close look at the relay board, as I saw the hints that it did power detection. The build quality is good, on par with in-wall modules I bught at the local big-box store. I was also impressed that the relay is a 16A DPDT relay with the two sets of contacts paralleled. This is likely a value engineering item, as DPDT relays are likely cheaper in the dimensions needed for this use, which is a value engineering item in the good direction which we don't see often these days. I didn't remove the switch board but it looks similar to the Martin Jerry single pole unit, which used a proper microswitch for the main switch and not a cheap PCB switch. This one has the same tactile feel.I said this on the single pole switch and I'll comment again here, the feel of this switch is very different than a normal switch: You're clicking a microswitch not toggling a real power switch. Another reviewer referred to "passing the wife test" and that's a fair concern. It feels more like a computer mouse than a wall switch. This is also a fairly chunky unit, by necessity, so it will need some decent room in the electrical box. HOWEVER, if these are concerns and you have the ability to add another electrical box this unit can give you the best of all worlds. Add a oversized box, like a 4 square (these work fine in 4 square steel boxes with a plastic wallplate, got 2 of them installed this way) somewhere out of the way and install this in it. Upgrade your two way switch to a 3 way switch, or the 3 way switch to a 4 way, and now you still have the normal, tactile feedback, normal switch operation, and the automation benefits. The state feedback and ability to work at either end of the chain allows this. Best of all worlds, if you can add a box and pull some wire.No internet needed for this, just DHCP. NTP isn't required but you'll want it, with NTP it's a self-setting timer as well. Tasmota firmware works out of the box. It does need a neutral wire no matter what. Same complaint I had about the single pole units with the plastic ears, it's the same housing, but so far that hasn't been an actual problem.Full 5/5 stars, I'm genuinely impressed that the output state is known regardless of configuration.

I reset the module and couldn't get it to work right, so I contacted support. They responded in a few hours, and told me what I needed to know. If you find yourself in this situation:1. Configure the module as 'Tuya MCU (54)'2. Set the template to:{"NAME":"MJ 3Way Switch","GPIO":[255,255,255,255,52,53,0,0,21,9,157,255,0],"FLAG":0,"BASE":18}3. In the console, enter:switchmode1 5TuyaMCU 11,1That's it! You're back in service. Now take a backup.

I really like that this product is pre-flashed with Tasmota. I was able to get this working with a typical HomeAssistant/Tasmota/MQTT recipe just fine.In my case, it's bad because I'm trying to make these lights behave as closely to the MJ-S01 switches that are also running Tasmota. I'm configured my MJ-S01 switches to have the RED status indicator ON when the lights are off. I achieve this through some configuring GPIO just fine. However, the same ability does not exist for these devices. I can only control internal behavior through the limited controls offered by TuyaMCU. Consequently, I can't configure the RED LED/status-indicator behavior.My major dislike is that this product is using Tuya underneath, and I'm limited to the TuyaMCU commands. For some, this might not be a big deal. If you're fine with no LED/status-indicator that is on when the lights are off, this product will be fine for you.UPDATE: bumped review to 3 stars. another bonus I accidentally found is that this switch seems to support using them as a pair in the same circuit without a dumb switch. Martin Jerry was very surprised at this because they say the switch was not designed for that setup. However I have 4 circuits all paired that way. While I can't guarantee it'll work in your setup, it seems to work in my house. The SmartLife version of MJ-ST01 definitely does not support wiring configurations that omit a dumb switch in the circuit.