Trying to synchronize some LCD comments, copied below, and replying inline:
> From Grant Richter:
> RE: LCD display
> 4 pins would be Ground, TXD, Reset amd +5 volts, is that correct?
> The voltage regulator is only a TO-92, don't plan on powering the LCD if
> it draws more than 25 ma.
Backlight is 160 mA. Sounds like the 4 pin interface means the LCD
microcontroller is on another board.
From Dave Brown:
> Two comments. First, I'd go with a 4 pin interface. I think there
> should be a ground and it would be nice to tie the resets together.
> You can do them independent but you have timing issues on power-up not
> knowing which processor is active first (although the displays take
> some time to initialize.
Dave's proposal assumes a simple 2 wire serial interface between the BASIC
ATOM PRO, a secondary microcontroller on a secondary board that converts the
serial 2 wire to the common LCD 8 bit data and 3 control signal logic, that
goes to the LCD's onboard LSI controller that drives the LCD segments and
commons.
From John Loffink:
> Doing a little research, I found the following Lumex LCD.
> LCM-S01602DSF/C
> LCD 16x2 STN Y/G LED backlit
> $13.36 available from stock from either Mouser or Digi-Key
> Board size: 3.346 x 1.181 inches
> Width just fits within a MOTM 2U panel. Height is as little as can be
> expected for a 2 line LCD.
I'll dump the LCD data sheets in the files area. The only difference
between this LCD and the dozens of others from Mouser and Digi-Key is the
smaller height.
John Loffink
The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.comThe Wavemakers Synthesizer Web Site
http://www.wavemakers-synth.com > -----Original Message-----
> From: ComputerVoltageSources@yahoogroups.com
> [mailto:ComputerVoltageSources@yahoogroups.com] On Behalf Of harrybissell
>
> Hmmm... The LCD display chosen should probably have its own
> micro and drivers on board. The only downside is that ties you to
> a smaller number of displays.
>
> I'd suggest choosing one that is multiple sourced and has a simple
> interface so that obsolescence does not occur too early
>
> The number of lines to drive the dispay of the LCD would be pretty high
> if all
> the electronics are offboard (ie on the main PCB).
>
> H^) harry
>
The LCD has on onboard LSI controller, but not suitable for direct
interfacing to the BASIC ATOM PRO. It steals too many of the digital IO
pins. The microcontroller I'm talking about sits between the BASIC ATOM PRO
and the LCD's onboard LSI controller.
Dave Brown and I discussed this one the phone extensively. The eight data
and three control signal interface is on everything sourced from Mouser or
Digi-Key. That should be the way to go.
Number of lines is controlled by a two wire interface from the BASIC ATOM
PRO to the secondary microcontroller. LCD commands are MIDI Sysex, then
MIDI is passed on to the MIDI port. Secondary microcontroller then drives
the LCD LSI controller parallel interface.
Dave already has most of the code needed to do this (see previous threads).
I could do the secondary LCD microcontroller board, unless Dave prefers to
do it himself.