Problem with LCD 16x4 I2C and ESP32

[COMTEC_80]

Hi,
i suspect that there is a problem using display 16x4 (also 16x2) I2C and ESP32 in real hardware (simulation ok).
When start circuit display backlight go off and writing is ok but very slow; i have test all configuration of I2C but only partially working is software mode other not....

[BenR]

Hello,

Please can you attach your program and maybe take a video of the problems your seeing on the hardware.

[COMTEC_80]

Hi BenR,
in attachments You can see display before start program and after launch program with string "Start" composing slow and backlight down...
Display is 2004 I2C SUNFOUNDER.

[APSALTER]

This problem also occurs in V9 on I2C LCD 2004 display from AZ delivery and pic 16F18877. Backlight is turned off after execution of any I2C LCD command with the exception of any of type "print" which has to be followed by a "back light on" for each statement to display the result as demonstrated in the test extract below.
.
.
.
LCDI2C!::Backlight(1)

LCDI2C1::Cursor(10.1)

LCDI2C1::PrintNumber(5678)
(Backlight is off for delay period)
Delay 5s

LCDI2C::PrintAscii(88)

LCDI2C::BackLight(1)
(Backlight is now on)
.
.
.
Inserting an additional "LCDI2C::BackLight(1)" immediately before the delay gives the correct display.

[BenR]

Hello,

Many thanks for letting us know. I have hopefully now found and fixed the problem and the backlight should now be on by default when starting the display and should remain on unless switched off.

[APSALTER]

Many thanks Ben for the prompt fix.
All LCDI2C commands now work with backlight on, also backlight on and off commands work ok.
Regards.
Andy.