glcd displays

[Wp100]

The HD44780 16x2 displays have been around for many years and seem likey to continue for many more, so choosng and using one in a project is no problem.

However with the few glcd based projects I have done, within 5 years the displays have become obselete, usually meaning you have to start searching for another and rewriting the driver or having to find new mounting and connectors etc etc

Are there one or two displays of modest size, say 128 x64 or greater that seem to be standing the test of time, availabilty wise, and are sensible prices ?

Only looking for text and simple mono graphics.

The EADOG units seems good, but not cheap and not served well in the UK, and athough always around the KS0108 with their dual controllers are a pain to program

thanks

 

[Ian Rogers]

How much???? Rapid do a T6963C 128x64.... But I use the KS0108 quite a bit and programming is easier than the Toshiba!!

What micro do you use.. The reason I ask is writing to an LCD is far simpler if you use a backbuffer... That means 1024 bytes...

 

[Wp100]

Was using the Pic18F4520/4620 chips with Assembly, the code for the ks0108 was a pain, though the EA Dog SPI was a bit easier.
Yes,did use a back buffer as you call it on the later efforts; originally just printing stored strings and images.

Now on a project with the Adruino Mega so at least there are pleny of ready to use libraries.

Seems the ST7920 is the modern equiv of the KS0108 but has the benefit of SPI. Think that might be the type that will be around for a while ..?

The EA Dog displays are very handy to use with the 0.1" pins, seems RS are now stocks some, but the full range is still only available from the UK main importer MMS, but you alway have to put in a price request. Think EA also have a ban on their dealers selling to other counties, or at least used to.

 

[Ian Rogers]

MMS-e is expensive on all his products... That is why I use Rapid.... I have been buying the mikroE 128x64 with touch panel from RS.. It cost me £16 and it has a touch panel.... It is ideal for my new range of monitors...

 

[Wp100]

Have been giving RS a closer look, seems they have a lot more hobbyist type of stock these days.
( been an account holder with Farnells since RS would not give me an account when I first started up my business long ago, thought the RS salesman , who had come round to see me was going to cry at the thought of having to turn down another potential customer due to, the then, RSs new minimum yearly spend rule)

Not a lot cash wise between the EA Dog and those MikroE displays...

Did get a simpler 4x3 cell type of touch screen overlay for the EA dog 128x64 some years ago, it seemed to work ok on the bench though never used it in an actual project; again hard to buy, only from MMS.

Your MikroE one working ok by the sound of the above, though your recent post on in that glcd sticky it still seemed a bit temperamental ..?
Like the keyswitches I use, think having a screen or switch stuck on watchdog type routine is essential.

 

[Ian Rogers]

The original touch driver I wrote was a bit temperamental.. Since then I have rediscovered a proper way to read the touch panel using a Z parameter.... This makes it much more stable..

But!! As I use MikroC for pic 32, I tend to use their library!!! It works beautifully.. I am ( as we speak ) just finishing the larger 240x128..... A few bugs to iron out, but its looking good...

 

[atferrari]

The reason I ask is writing to an LCD is far simpler if you use a backbuffer...

What is a backbuffer Ian?

 

[Ian Rogers]

If you draw a text string onto the screen ie.. 12:12PM Right in the middle of the screen, then at 12:13 you write the new number the number 2 at the end will corrupt.... The 2 and 3 will use different pixels.... So!! You need to clear that part of the screen to redraw the next number or draw the old number with the back colour, to rub it out... Lots of flicker and a pain in the harris!!

If you create a "Backbuffer" you draw the entire screen out of view then blit the new screen in one go.. all changes are a lot smoother... Writing to a backbuffer is to direct memory so incredibly fast.. Writing the screen in one go is also fast..

With the toshiba they provide an autowrite...so imagine this..

clearscreen()
{

autowrite on;
while(every screen byte)

write empty byte;​

autowrite off;​

}
Really fast clear routine.

blit()
{

autowrite on;
while(every screen byte)

write byte from backbuffer;​

autowrite off;​

}
Really fast blit routine.. on a pic18 and a 20Mhz crystal it will take about 56mS to blit the screen so no flicker whatsoever...

I hope I haven't gone over the top!!!