Adjusting the light intensity with lcd.backlight () function

[ptillisch]

Hi @viet5d.

@viet5d

Can I use lcd.backlight(50) to reduce the light intensity to 50% ?

The answer to your question depends on which library you are using. There are several different LCD libraries. Some of those might provide the capability to adjust light intensity. For example, if you read the other forum topic you linked:

@bperrybap

The LCD API 1.0 defines 3 functions for backlight control:
backlight() - turn on backlight
noBacklight() - turn off backlight

setBacklight(dimlevel) - to turn on backlight with dimlevel backlight intensity

From looking at the code for the noaiscaLiquidCrystal library lcd_4bit i/o class. it looks like, unfortunately, it doesn't implement this as specified in LCD API 1.0 so there is no way to set a backlight intensity even if you call setBacklight(dimlevel)

So please tell us which library you are using.

If you installed it using the Arduino Library Manager (Sketch > Include Library > Manage Libraries... in Arduino IDE or Libraries > Library Manager in "Arduino Cloud Editor") then say so and state the full name of the library.

If you downloaded it from a website, then please post a link to that website.