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Forum Index : Microcontroller and PC projects : LCD Backlight Control
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OA47 Guru ![]() Joined: 11/04/2012 Location: AustraliaPosts: 915 |
Reading the Pi Pico manual and the section on LCD backlight: Do I need to use a transistor to intertface from the Pico to the LCD or can I connect directly from the GP to the LED pin? 0A47 |
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palcal![]() Guru ![]() Joined: 12/10/2011 Location: AustraliaPosts: 1809 |
I use the circuit from the Micromite Backpack, look on Geoff's site. "It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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disco4now![]() Guru ![]() Joined: 18/12/2014 Location: AustraliaPosts: 854 |
It will depend on the LCD Panel. The earlier ILI9341 only exposed the backlight LED Anode (LED-A) so you need to supply enough current hence a transistor. Most now expose the BL pin as a logic level and can be driven directly. On the ILI9341 inspect the LCD and see if the BL pin heads towards a resistor and transistor. I think the ILI9488 have BL going to R6 and Q1 so only a logic level is required. Latest F4 Latest H7 |
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OA47 Guru ![]() Joined: 11/04/2012 Location: AustraliaPosts: 915 |
Thankyou Disco4now, the LCD panel I am using is indeed an ILI9488 and I traced the PIN labelled BL to a transistor circuit so I connected it to a PWM pin and all works fine. 0A47 |
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