I excitedly received a ESP8266 based 5v relay board today (https://www.ebay.co.uk/itm/ESP8266-5V-WIFI-Relay-Module-TOI-APP-Control-For-Smart-Home-Automation-System/202004110898). The ESP8266 daughter board looks like the AI-Thinker ESP 01 (but is not badged as such). It is configured via serial connection. I am using a ch340 usb to serial. I am powering it with a USB phone charger (5v; board has a 5v>3.3v reg). The device appears to power on correctly and creates a WiFi AP with SSID AI-Thinker_xxxxxxx. I can connect to that AP and ping the device. I believe it has
stock Espressif AI-thinker firmware but do not know the exact version.
I have tried all the common baud rates (9600, 57600, and 115200) but only get something unintelligible where I should get the boot welcome. I have tried gtkterm and minicom (on Ubuntu). I also tried PuTTY on a different laptop with windows. Still get the same (i.e. same output for each baud setting). It does not appear to respond to commands.
What is the next step to diagnosing what's wrong?
[Update]- 1) The initial baud should be 74880 according to http://wiki.ai-thinker.com/_media/esp8266/esp8266_series_modules_user_manual_v1.1.pdf . I have tried this (tx and rx) but still get junk.
2) This thread http://www.esp8266.com/viewtopic.php?f=6&t=4459&start=4 suggests some units are dodgy and I should try reflowing solder joints (TX does look a bit dry) and/or flashing firmware.
3) In the mean time I ordered a new nodemcu board with a built in USB TTL.