This is idea I’ve been kicking around for a few days now, using a Ti calc to control a LCD module. To make things easier, I’ll abbreviate the name for “Calculator Controlled LCD screen” to the “LLC”. I was inspired by one of my other projects, the unfinished LCD tester.
The calculator has a serial port which would hook up nicely to a shift register, enabling all of the lines to be controlled. There’s one problem however, the calc only has 2 data lines. Every shift register employing LCD circuit I’ve seen requires 3 lines. The first is the data, the second is the clock, and the third is for the enable line.
However, a convenient solution appeared in an All Electronics catalog. They sell an LCD IC that takes a serial input and drives the pins of the module. The best part is, it only requires 1 input line. The only remaining challenges are writting code to modulate the linkport at 2400 baud, and figuring out the input format to the IC. This is merely identifying how the IC wants the incoming data to represented.
the ti83?,85,86 will connect to a pcf8574 i2c pI/O expander. using the two lines and give you 8 i/o lines. you will need the schematic by pier fiander to do it should be able to find with a simple search.
Comment by Glenn Clabough — September 16, 2011 @ 8:30 am |