TFT driver example

Hello,

Does anyone have sample code for using the direct drive feature to drive a TFT LCD display in the H8SX series?  Also, does anyone know of a decent graphics library that would support color VGA displays?

Thanks,

JeffH

A full CD should be available from your Renesas supplier...

However, you might want to give this a try (I can't try it myself...)

http://america.renesas.com/fmwk.jsp?cnt=s2_config_drivers.jsp&fp=/products/mpumcu/h8_family/h8_lcd/easy_steps/

Post back with your results.

We have implemented a product using this technology.  Like everything else in the world, there are some pluses and some minuses.  Examples:

1) (-) The system requires external RAM as a display buffer.  But the display is using so much bandwidth that you can't really store anything else out there, in either RAM or FLASH.  So then, where are you going to store your graphics ie bitmaps?  Internal memory quickly becomes limited.

2) (+) You aren't tied to someones single sourced controller that costs $14...

3) (+) You get the source so you're in control.

4) (-) It only uses about 5% of the CPU to keep an image on the screen, but to change the entire image it pretty much kills the system.   This is mostly due to the fact that the H8 isn't really moving very fast and would be true even if using an external controller.  Plan on using an RTOS because a call to a library API may take several hundred mS, shutting down everything else.

5) (+) It's really very straight forward to get running and put a dot on the screen.  Pretty much a short init routine, then a short interrupt routine.  

As for a graphics library, we have ported both EasyGUI ($1500?) and Seggar ($20,000?) and both have excellent qualities.  Obviously Seggar has more "stuff", but support from both has been great. 

Good luck!

Bill

Just a note, the manufacturer of the second graphic library is Segger (www.segger.com)

Thanks for posting your experience. That's exactly what we want users to do on RenesasRulz.

As for the memory issues: It is possible to set up a buffer for memory dumps to the LCD that would require a small CPLD. This would allow 32 bit memory writes to be buffered and delivered to the LCD in 16 bit chuncks (24 bit when dropping some of the LSBs). This adds to the hardware design, but makes for a more efficient 32 bit memory bus for data delivery.

External RAM can be paged, if you are willing to write images to two screen buffers instead of one. This is usually the solution if users want to store lots of images in internal FLASH (up to 1M on some chips) or external SPI Data Flash devices.