I have had an idea but not sure if it would really work so i would like your opoinions
if i connected another 2x16 lcd up to the same data pins as i have on the first one and connect the enable line of the second one up to another data line on the port and set lcd smartie to use a 4x16 LCD would it use the first LCD as lines 1 and 2 and the second one as lines 3 and 4 ?
if so can someone please advise the pins to connect the two enable lines to make it work with smartie.
would be cool if that worked
what do you guys think ?
i have just done a quick search and fount a few diffrent ways of it being connected. one of them uses pin 9 as an E2 (in use as D2) and the other one uses pin 17 (witch i already have in use as a software backlight control IIRC. been a long time since i made it)
so if you could post a 4x40 schematic that has been tested with lcd smartie i'm sure i could adapt it acordingly
There's a (rather crummy) schematic for 4x40 LCDs on the Smartie circuits page - second one down.
You'll need to set Smartie to use a 4x40 display, but make sure that all your screens only have up to 16 characters on each line. If any of them go over 16 characters, some strange scrolling will happen on your 16-character wide displays...
This is what i plan to do. i don't understand why i need to set smartie to use a 4x20 display ??. does a 4x16 only have one controller or am i missing somthing else.
i will try this as soon as i get my hands on another 2x16
also, will this affect the framerates at all ? (i dont think it should and if it does prob not enough to worry about)
Also pin 17 is now connected to register select. i was using this as a software controlled backlight via a transistor. Is there a alternate setting that will allow me to use another pin. or does the software controlled backlight have to go ?
EDIT : just checked port pinouts and it dosent look good for my software backlight :-< oh well
You need to set smartie to use 4x40. Otherwise it will think there is only one controller. But you cannot go over 16 characters per line because that is the actual size of your display. If you do (like mattcro said) it will do very strange things.
ok, thanks for clarifing. i will try this as soon as i get another display.
that just leaves one thing , the software backlight.
am i right in thinking that i will not be able to use it anymore ?
that would be a shame because what else am i going to use the display button on my xbox remote for lol.
thanks for all your help guys
hey guys... I have a box of something like 50 of these 2x16 HD44780 displays at work so I thought I would try the 2 displays on one port thing. Did you ever get this working properly?? I have wired mine up as in the modified wiring diagram posted above, but LCDsmartie wont enable the second display!
MPXPLAY will happily talk to either display seperately but won't talk to both at once. (I swapped the enable control bits and each display worked seperately but the other remained blank)
I am using same schematic as posted by fatboy11 with all pins on the second display connected in parallel to the first except for the enable pins. The enable pin on the second display is connected to parallel port pin 17. I have tried setting 4x40 display
I am sure this is a software thing because both displays will enable and display text seperately from each other quite happily when the correct enable pins are specified in mpxplay, but only one works in lcdsmartie...
The weird thing is that in playing around with millions of different software things at once, I pressed some buttons in the right order or something and both displays started working perfectly with lcdsmartie!! I closed all related programs and when I started lcdsmartie again it was back to not working...
Can a developer confirm that smartie outputs the correct enable signal on pin 17 when 4x40 display is connected? (or 4x16 for that matter... that would be even better!)
i will be trying this then 
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