So I have this keyboard / LED driver circuit, and I'd like to replace all this with a nice, compact 4x20 LCD and some kind of PIC (Arduino, Raspberry Pi, whatever).
I've already worked out the basics as to how I want the LCD laid out, and what to write based on the contents of the display buffer.
The display buffer has up to 8 readout digits, two test number digits, and six status LEDs (red / green / yellow / off).
There is also a 4x4 matrix keyboard involved as well.
In case it's not apparent on the schematic, here are the signals on the J1 connector:
Reset - system reset (active low, but the 8279 uses an active high reset)
R/W - read / write line (again, the 8279 prefers the one line be broken out into two)
IRQ - this is an active high line to tell the system that a key has been pressed
_CS - chip select
A00 - this tells the 8279 whether it is to act on data or to accept commands
Clk - system 1MHz clock
D0-D7 - system data bus
As for output? Easy. I2C interface to an LCD.
I don't know that much about how to select an Arduino, Pi, or whatever, so would appreciate some input...
I've already worked out the basics as to how I want the LCD laid out, and what to write based on the contents of the display buffer.
The display buffer has up to 8 readout digits, two test number digits, and six status LEDs (red / green / yellow / off).
There is also a 4x4 matrix keyboard involved as well.
In case it's not apparent on the schematic, here are the signals on the J1 connector:
Reset - system reset (active low, but the 8279 uses an active high reset)
R/W - read / write line (again, the 8279 prefers the one line be broken out into two)
IRQ - this is an active high line to tell the system that a key has been pressed
_CS - chip select
A00 - this tells the 8279 whether it is to act on data or to accept commands
Clk - system 1MHz clock
D0-D7 - system data bus
As for output? Easy. I2C interface to an LCD.
I don't know that much about how to select an Arduino, Pi, or whatever, so would appreciate some input...
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