SONOFF S40 Lite 15A WiFi Smart Plug ETL Certified, Smart Socket Outlet Timer Switch, Compatible with Alexa & Google Home Assistant, IFTTT Supporting, No Hub Required -A Certified for Humans Device

Sonoff has a reputation for being very friendly to developers and home-automation enthusiasts. It is a very common practice to flash alternate hardware on these. Of course, doing so voids any sort of warranty and eliminates the possibility of sending them back, so its always done at the purchasers own risk. That being said, Ive had no problem with other Sonoff products. However, these are a disaster. I destroyed one just trying to get the screws out. They are in far tighter than could ever be necessary. Another one I destroyed by trying to solder little wires onto the pads for programming. One of the pads came off. All of these might still work with the original firmware, but they are completely useless to me that way. They require Internet connectivity to work, so what happens when my crappy satellite internet fails? I have to crawl around under tables and behind furniture to find the little buttons that I have to press just to turn things on or off. This has been a major disappointment for me. I thought Sonoff treated their customers better than this.

Enclosure design is excellent for getting access to innards to flash custom firmware (Tasmota in my case). Not glued together but held together with snaps and screws. Build quality is good. Did not use stock software to control with Alexa but flashed firmware for local control (device does not “phone home” to China. WiFi reception is strong with the ESP chip (stronger than many comparable devices). So far, very pleased with design and results. All together, I’ve purchased 8 of the S31 (both Lite and EM versions) and they all work (some other brands were somewhat hit or miss). Good QC.

Use caution when ordering these. I didn’t realize there were two versions of the S40 Lite, Zigbee and Wi-Fi. I bought this version by mistake, and while they’re returnable, I don’t have a UPS store near me and Amazon won’t provide a free return label for a pickup. The Wi-Fi version does not seem to be as well supported in home assistant, the add on provided for it only seems to provide a Lovelace card and not a proper device, so as far as I can tell so far it can’t be used in automations. The s40 version also can’t be flashed with alternate firmware, so it’s usability with home assistant is limited.

I wanted to use this for bedroom light, which I can shut off from cellphone from bed, and start-on by toggling the wall switch the next day (by setting default-power-restore status = on in the setting). Working great!

This is my fourth son off product and I’m very pleased

I will definitely buy this again when I have other things I’d want to time! It’s small enough you can use both plug ins and is just amazing! Just download and app have Bluetooth and then we the time!! Greatest product ever!

These work great for flashing Tasmota, but you need to be familiar with the flashing process. Here are some tips: - Highly recommend those rubberized Mini probe test leads to clip between the board and FTDI flasher to avoid the annoyance of doing a hard solder just to flash the device. - Any basic FTDI-type USB flasher will work, just make sure it can provide 3.3v (make sure to set it to 3.3v before connecting!). Theres a cheap FT232RL $5 one on here--make sure you have any requisite USB connector for it (mine needed the uncommon USB mini adapter). - Opening the Sonoff isnt terrible difficult, use a spudger or mini flathead screwdriver to pop off the grey cap on the side facing the plug. Remove the white sliding things, and be gentle doing the 3 screws since they strip easily. - Grab the latest tasmota.bin from Github. There are multiple tools that can flash it, I used ESPHome Flasher. - Flashing: 1. Connect GND, RX, and TX probes between the Sonoff and your FT device, but dont connect VCC just yet. GND goes to GND, but RX goes to TX and vice versa! 2. Plug in FT device to computer. 3. HOLD DOWN button on the Sonoff device and connect VCC--if your FT device has LEDs they should flash but Sonoff should not. 4. Refresh ESPHome Flasher and it should detect your device on the USB port. Load the firmware .bin and flash it. 5. If successful, put the Sonoff back in its housing and plug it into an outlet to test. Use your phone to connect to the temporary AP so you can give it your wifi details. Thats it! Future updates can be done OTA.

I read somebody else’s review that said it worked with 5 G however, I was not able to make it work with mine. My equipment is supposed to be able to adjust down to 2.4 g. THIS IS NOT THE FAULT OF THE MANUFACTURER because they clearly state that it is for 2.4 g.

Trash product, I literally tried every possible way to get these to work and nothing helped. I literally just threw them away. It was worth the trouble to return them.

Great for high amperage devices. I wanted a smart plug that could handle 15 amps to control an electric heater with Alexa. This fit the bill.