There isn’t a jumper cap when the LCD module comes in. I put on a female-female dupont wire and the backlight turns on, but the LCD only displays one line of black squares instead of HELLO WORLD.
The library is installed by git clone https://github.com/marcoschwartz/LiquidCrystal_I2C.git into My Documents\Arduino\libraries. Frank’s library is not installed.
I2cScanner says No I2C devices found. I guess this means a faulty connection?
Since LCD is displaying text correctly on the other ESP8266, the problem might be in the NodeMCU.
I’ll test other pins and test D1/D2 with LEDs to see what’s going wrong.