I'm looking at this serial enabled LCD screen for a project of mine. I noticed the LCDs that are not serial enabled require a lot of pins. But my project will involve multiplexing about 60 LEDs and pulling states from rotary encoders, along with needing to update a digital pot pretty quickly.
Would a serial LCD screen cause a lot of lag? I've already got a lot of timing stuff to deal with, I'm worried about piling more on. If I get one without serial, would it be very difficult to manipulate it with shift registers or something that doesn't eat up a lot of arduino pins? What is a smart choice of action here? I plan on using the screen to have named presets for my project. I really would like to have an LCD screen but I welcome any ideas.
Potentially, yes.
Serial prints are blocking, that is, they don't return until the last character in the string has been written to the transmit buffer.
At 9600bps, each character takes over 1millisecond to transmit.
You should increase the speed to the maximum (38400 in this case), and avoid printing long strings, or at least avoid printing long strings in a single "hit", which will mean checking to see if the transmit register is empty before writing the next one, or writing your own interrupt-driven serial driver.
Well, I2C usually starts at a clock speed of 100kHz, and apart from the need to send device and register address, overheads are not much different, so a bit less than ten times faster, in theory.