Review on 🏠 HiLetgo ESP8266 5V WIFI Relay Module - Smart Home Automation System with TOI APP Control by Abdirahman Elmer

As other reviews point out, the Chinese documentation is pretty terrible. My use case for this device was on an ESP8266-01 control relay using my own code. I liked the given form factor and didn't really need much documentation; The price was ok so I took a chance. Please note that when you go to the site listed on the device, you not only get an insecure Chinese-only site (slow when accessing from the US), but all the information/letters are in images (probably copied from other sites? ) i used my camera to translate and it sounds more or less exactly like the text that is hard to understand on Revain (and the link someone kindly provided on create.arduino.io). In other words, there appears to be very little information about this device on purpose. The contact information on the website does not match the website domain - many red flags of trust and reliability. Program. I'll probably just pull the relay and maybe the regulator off this board and smash everything else. Please note that I really appreciate that the device comes pre-programmed with ESP8266-01, but this code is as insecure as it gets. It is forbidden. There's no way to just turn it on and set it up with your phone, and you have simple commands, no state, no nothing, so it's really just a toy. Everything is fine for that. But not suitable for my use case. The first big problem is that there is no way to ground D0 so you can program! My device has 3 "extra" pins, one of which claims RST status (does not reset when low). In fact, it would be better with a button for that. And if you want it to be FTDI compatible (you can't do it without pulling D0 to GND), RST needs to be connected to RTS so it can properly reset the device after programming. So the bottom line is that you have to program your device "elsewhere”. And if so, I can test the device "elsewhere" and don't need the FTDI pins at all. Or even better, add a USB interface to the blank bottom and avoid voltage problems. As other reviewers note, the board has a second microprocessor (N76E003), which doesn't make much sense given the application. We're talking about a single on/off output, and the ESP8266 has two pins that work great in a standard configuration. Hell, they have to use one of them to communicate with another microprocessor! The reason for a second processor can only be related to undocumented features that disqualify the device. I really like the 3.3V ESP8266, so the 5V requirement here pushes me in the wrong direction. I need to provide 5V just to match it and at the same time it's not clear if the FTDI lines should follow the ESP8266 3.3V or 5V? I don't see the MOSFET voltage conversion, which probably explains why mine is running relatively hot on this device. The board says 5V on VCC, so you can assume that TX/RX will also be 5V (and if you set FTDI to 3.3V, the VCC line will also be 3.3V!). It would really be a lot easier if they just used a 3.3V actuation relay instead. less energy and full control over programming, OTA setup and secure SSL implementation to communicate with the device. This means I can write the state to NVRAM so that when the device is powered off it can go back to the same state it was in before it was powered off (or use a latching relay). Perhaps using this board as inspiration for the compact layout would be the greatest value of this block. Not sure yet. So if you just want to write serial commands and see how the relay is driven, this is a good little board for that. But you can do it very easily with a breadboard and a relay (just use a 3.3V relay). Add a protection diode to avoid coil feedback and you're done. D0 or D2 is then connected directly to the coil, or if you are careful via a simple NPN transistor/MOSFET. And now you are responsible for what turns the signal on/off.