Enable/Disable keypad and lcd backlight separately? (635)


New member
I was wondering if anyone knows a way to set the LCD backlight on and the keypad backlight off on a 635.

It doesn't appear that the CFA-635 command set has a way to do this, is there a way to interact directly with the LCD via Command 22 to get this to work?

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New member
Switching them separately isn't possible, the LCD & Keypad back lights are driven off the same circuit.

Robert Heffernan
USB LCD Displays - Graphic and Character LCDs with a Keypad

CF Tech

There are some traces on the PCB to support this as a custom option, but it is not something a typical user could implement. I think there is a transistor and resistor that have to be added as well as some jumper changes. The option was intended for one of our OEM customers that orders in larger quantities (100+) and needed separate control.