40x4 LCD not working

[JuanGg]

I have purchased a character LCD from here: https://www.buydisplay.com/40x4-lcd-module-datasheet-commands-arduino-pinout-hd44780-black-on-yg



Following the datasheet, I tried to initialize it manually using dip switches, but I could not get it to work.
The LCD uses the standard Hitachi interface, with two enable pins.
On power up, the usual black squares do appear, and contrast adjustment works fine.


I tied the second enable low, and connected the first one (E1) to a de-bounced switch.
With E1 high, I tied RS and R/W low, wired the data bus to 00111000, and changed E1 to low. That should initialize the display, but I see no changes on the screen, I suppose it should go blank. (I've moved the contrast pot around).
I've checked the connections a dozen times, soldered some decoupling capacitors right to the connector, but no luck.
I don't know how to proceed. It could have been damaged by ESD, but in such case, would it even show the initial squares?
Any ideas are welcome.


    Juan

[rhodges]

Okay, 0x38 chooses 8 bit mode and display lines. That is what I use, except mine uses 4 bit mode (0x28).
Here is my init code: (RS pin is low)
    lcd_comd(0x28);             /* 4-bit mode, 2 lines */
    lcd_comd(0x0e);             /* turn on diplay and cursor */
    lcd_comd(0x06);             /* auto increment and move cursor */
Then send characters with RS pin high.

My code for STM8 might be of some help:
https://github.com/unfrozen/stm8_libs/blob/master/lib_lcd.c

[JuanGg]

Thanks. Found the issue in the end. I copied the pinout on a piece of paper and missed the order of the data bus...It's working now.
    Juan

[JonInPalawan]

How did you get contrast adjust to work? My display is Surenoo, and I tried to follow their conflicting instructions. Can't make the faint 5x8 dot pattern to adjust out. 
Initializing was easy. Just set the required data, then pull both enables low then high again. Repeat for next data. The two controllers work independently, though they share the common data bus.