LCD Sleep Mode Issue

Hi ALL,

Regarding this LCD:

https://www.ebay.co.uk/itm/3-5inch-TFT-Color-Screen-Module-320X480-Ultra-HD-LCD-Shield-for-Arduino-UNO-FT/112790945520?hash=item1a42dd3ef0:m:miQ_f6oi8m3Qb6KK72-o1Mg

I tried to set it to sleep mode according to HX8357B datasheet, but unfortunately it gives me white screen (Back Light of LCD is ON), Does this means that the Back Light is hardwired and can't be controlled from my arduino MEGA ?!

Thanks,

You can send the controller to sleep. The display in your link has no access to the backlight. It also contains an ILI9481. Why do you talk about HX8357-B ?

There is little point in sending the controller to sleep if the backlight is taking a massive current.

David.

The only Library that works well with the LCD is the HX8357-B Library.

Referring to the datasheet, when I send the LCD Controller to sleep it just clears all the data but leaves the Back Light ON (White Screen).

Sorry David i post the wrong LCD, this is the LCD i meant:

HX8457B LCD Link

The same answer applies.

There is no access to the backlight on that Shield either.

You can send a Sleep_In command (0x10). The display will go white. Send Sleep_Out (0x11) and the picture will appear.

David.

So the only solution here is to switch the whole LCD using a MOSFET for example, So instead of sending a Sleep Command I will disable the LCD but in this case I have to know which data I was showing before power off.

Korawy:
So the only solution here is to switch the whole LCD using a MOSFET for example, So instead of sending a Sleep Command I will disable the LCD but in this case I have to know which data I was showing before power off.

Not the whole LCD, the backlight. This is essentially always a separate connection - if the shield does not permit this (it is stupidly designed) and you need to modify it to separate the backlight connection.