On Sun, 1 Apr 2018 18:59:57 -0700 (PDT),
engine...@gmail.com declaimed the
following:
The first step might be with bi-directional level shifters. The IN/OUT
voltages look be following TTL transition levels, and while the minimum
value for H is safe, the maximum value could be too high for the 3.3V
Beagles. You /might/ be able to drive it if you never connect to a
read-back pin, though you'll still need to provide it with a 5V power
supply.
This is a Parallel type display, and even in 4-bit mode, will require 7
GPIO pins (and 3 more if you don't hardwire the backlight color). In 8-bit
mode, you are looking at 11 GPIO (14 with backlight). I haven't checked the
processor documentation enough to know if there is a quick "port I/O"
capability -- having to set the data bits individually could be a bit
tedious (Yay! Subroutines!).
https://www.parallax.com/sites/default/files/downloads/603-00006-2x16-Parallel-LCD-Documentation-V1.4.pdf
is the old Parallax (BASIC Stamp) documentation for a parallel LCD display;
the odds are good that the unit you are looking at has very similar
features.
However, even Parallax have stopped selling a naked parallel LCD --
some years back they incorporated an add-on microprocessor to convert them
into a Serial interface (plain old UART -- but one-way, no ability to read
data from the display)
https://www.parallax.com/sites/default/files/downloads/27979-Parallax-Serial-LCDs-Product-Guide-v3.1.pdf
Still at 5V, however, but only needs a uni-directional level shifter for
one GPIO/UART line.
In contrast, their OLED unit is compatible with both 3.3 and 5V
systems, using a SPI interface...
https://www.parallax.com/product/28087
(Unfortunately, their web site seems to have hidden all the old
documentation links; kept having to use Google to find things)
--
Wulfraed Dennis Lee Bieber AF6VN
wlf...@ix.netcom.com HTTP://wlfraed.home.netcom.com/