I have a seeed studio volt meter, 0-30v. I'm trying to get it to dim like the rest of my circuit, but I can't find any information on the multiplexer? that they use in this circuit. It has no markings besides the dot beside what I'm assuming is pin 1. Has anybody figured out what they're using here? I just need to desolder the enable output pin (if it has one) and connect it to my board. Thanks!
You could more usefully have posted this link.
I would guess its an mcu of some sort. Maybe a Chinese knock-off of an AVR or PIC 16-pin mcu.
Three ways to dim it that I can think of:
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By updating the firmware on the mcu. To protect their IP, they will probably have locked the chip so that its program code can't be copied, and it may not be possible to update it in-circuit.
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You might be able to detach the display and introduce some extra circuit between the mcu and the display do dim it using pwm.
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Give up the idea and build your own dimmable voltmeter from scratch! Seriously. Easer than 1 or 2. You could do it with an attiny85 and a max7219, for example.