Getting back into electronics as a hobby, and I'm giving myself some breadboard tasks and drills to do to refamiliarize myself with both simple analog and digital circuitry.
Here's what I want to do: 5VDC source, with a pot (say, 100k). I want to take that analog signal and drive 8 leds which light up between 1 and 8 of them at a time depending on the relative output of the analog signal.
My first thought is 8 bit analog to digital. Got ahold of the ADC0804 chip (https://circuits-diy.com/adc0804lcn-8-bit-a-d-converter-datasheet/)
Simple hookup with a pot driving the V+ relative input, and my output was hooked to 8 leds through some current limiting resistors. I turn the POT and the output is 8 bit binary value displayed on the 8 leds.
Success!
But now my thought is, rather than displaying an 8 bit binary value, let's drive 8 leds which turn on successively more lights as the 8 bit output goes up. At first glance it might SEEMS like the same thing, but it's not.
For example, let's say the 8 bit output is 0b10000000. When displaying binary, of course, bit 7 is on, and bits 0-6 are off.
But I don't want to do that. That value is 128, which is half of 255, so the lowest 4 lights out of 8 should be on instead.
I'm racking my brain as to how to convert this without a simple microprocessor, which I can easily do. Probably could do it with TON of logic gates, but is there a 1 or 2 chip solution for this? I'm going through a bunch of data sheets, but since I don't know what this might be called it's difficult to find a prepackaged solution. Maybe I didn't need to convert to 8 bit digital in the first place, and there's a simple driver to accomplish this already?
This truth table might help (I've added some logic tables below the truth table). The logic table is how I could accomplish this with AND and OR gates. Would still love to know if there's a chip designed for something like this.
