Yunshan ESP8266 250V 10A AC/DC WIFI Network Relay Module

Original item. Approx NZ$6 with free shipping at the time (end 2019)
https://www.aliexpress.com/item/32967365594.html

This board was a bit fickle to get flashed and up and running with Tasmota, here are some notes.

The board I got already had the serial and 'boot' header pins in place, but some apparently don't have these soldered in place.

Original AP connection

I could not get the original http based controls working. I didn't want it, but I understood there was some basic control to begin with and it would have been interesting to see what they had in place. From a quick search, it was supposed to set up a wifi AP at

yunshan_wifi_xx_xx_xx (where xx part is suffix of MAC address)
or possibly
SSID: yunshan_wifi

password：yunshan123456789

I rarely got it to bring up an AP, but eventually managed to get it to broadcast an SSID of ESP8266. The above password didn't work however, and neither did a few other guesses (or blank)

Power

Mentioned on another link, but I too could not get anything working with a 5V supply. I eventually used a 12V plugpack (was ~1.5A). Remember to connect the gnd of the 12V to the GND of the FTDI adaptor. See my photos below for final connections that worked for me to flash.

Flashing Tasmota

I used NodeMCU PyFlasher to eventually get a Tasmota binary installed. Setting of baud rate 57600 and Dial I/O (it may have worked on a higher baud rate, but I wasn't going to try again...). The unit has 4MB of flash, so no mucking around with smaller binaries of Tasmota.

Putting into flash mode

- The timing to set it into boot mode was pretty critical when I was attempting it. There is a jumper for IO0 and ground (marked boot) . Put the link in place, power it up and remove in a couple of seconds. Other timing didn't seem to work. Some places say to leave the jumper connected until the flashing is complete, but again this didn't work for me.
- I also attempted to use some longer leads in place of the jumper so I could just hold them together on powerup, but this didn't work for me. Might have just been timing again, but the leads could be acting as antenna to the micro.

Links

Useful page with setup info:
https://ucexperiment.wordpress.com/2016/12/18/yunshan-esp8266-250v-15a-acdc-network-wifi-relay-module/
Relay (only) datasheet:
https://www.robotshop.com/media/files/PDF/datasheet-v1.0-dfr0017.pdf

Other:
https://arduinoplusplus.wordpress.com/2018/08/28/home-automation-and-the-internet-of-things-the-start/
https://www.reddit.com/r/esp8266/comments/58nnb0/any_documentation_or_instructions_for_this_board/
https://www.instructables.com/id/ESP-12F-Flashing-AT-Firmware/

Was supposed to be the product datasheet, but it has moved
https://www.uctronics.com/download/U4648-datasheet.zip

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