We have 2 of these and 2 different engineers trying to get them to work. They work as serial converters, but both the Reset and the GPIO signal happen at exactly the same time, for this product to work the reset should go low, then the GPIO 0 control go low, then reset should go high , and after a delay the GPIO control should go high. But both are occurring at exactly the same time. I am using a 200MHz storage scope to test. (Rigol DS2202). Has the device been shipped without the convertor being programmed perhaps?
I'm using this to flash the esp-wroom-32 module on my pcb, and it's working great. I was previously using the adafruit CP-2104 module, but the automatic bootmode wasn't working for me. This board solved that problem. I did run into two small issues with the ESProg, but those were quickly fixed. My board was expecting 5v, not the default 3.3v. There's a jumper on the bottom to be able to change the switch to support 5v. I also had to swap the TX and RX from what I had previously with the adafruit converter. It's a great little tool.
Works flawlessly, has a great assembly and high-quality components. I particularly like the power switch as you can do the programming without an external power source.
I plan to use it together with a clip with pogo pins for programming my boards without the need for soldering. And it'll also save some space on the boards itself as it eliminates the need for a flash button.
The instructions that came with this kit made it really easy to flash with an FTDI connector. The only issue I have had so far, is that the instructions did not include the details to put in the Arduino software. This may have caused me some issues, although it's possible I set some parameters incorrectly. I contacted the supplier, and he got back to me quickly with the correct parameters and some hints on debugging (and where my issue may have been). I set it up for a new network, used the correct parameters, and everything worked fine. The included Blynk code is well written and a useful basis for whatever you want to do.
The hardware is very energy efficient, can come with everything pre-soldered and ready to go, and has a wide range of sensors on board. Fantastic work! I will be ordering more to replace some old temperature/humidity sensors that I have at work.
In case you are unsure about the Arduino software settings, I used these ones: Board: Generic ESP8266 Module, Flash Mode: QIO, Flash Size: 1M (NO SPIFFS), Debug Port: Disabled, Debug level: None, IwIP: Low Memory V2, Reset Method: None, Crystal Frequency: 26Mhz, Flash Frequency: 40Mhz, CPU Frequency: 80Mhz, Builtin LED: 2, Upload Speed: 115200, Erase Flash: Only Sketch.