I would like to build a driver circuit (controlled by a microprocessor -- Arduino, Raspberry Pi, PIC, etc.) for an LED matrix to support a couple of features:
- Dimmable leds
- Simultaneously addressable (multiple LEDs can be turned on at once)
Application: Symbolic display (letters, numbers, special characters), charts (bar graph), art ("twinkling effect" via dimming)
What are some approaches others have taken? In particular, I'm interested in software solutions and minimizing resources (chips, component parts, etc...). Below are some approaches I think may work:
- Shift Registers to light individual LEDs very quickly at different locations while relying on persistence of vision (to make LEDS appear to be lit simultaneously)
- Decoders to manually address single anode/cathode pairs to light individual LEDS. Not sure how to make it dimmable.
- Encoders to complete circuitry to light multiple LEDs.