In SX Microcontrollers, SX/B Compiler and SX-Key Tool, Thurston_Howell wrote:

Hi, T&E Engineer.

I, too, ran out of program space.  I was using a 16F628A which has 2K of space, and switched to an 18F4550 which has around 40K I think.  Yes, it was the data that took up a lot of the room.

I was thinking about the displays and have a thought for you on how to use more of your 10 displays.  I did try running more than one panel with the same CS number and they both displayed the same information.  You could make a double-sided sign by having four panels on each side and running the ribbon cable from panel 4 on one side to panel 1 on the other.  The second side would simply show what's on the first side.  Also, you could do a two-line, 8-panel display with a bit of fancy programming.  Just set up 3 more pins to work the second display separately.  You would have outputs to two signs, and could display different text/graphics on each one.  The top sign (with four panels) could have a scrolling message while the bottom sign has a display of date/time, for example.  Since the data takes up most of the code, it wouldn't be too taxing on memory to do this.  I also thought about doing this and running it as one large sign.  If you made up a new font, you could split it from top to bottom.  The top sign would display the upper 9 bits of the font and the bottom sign would display the lower 9 bits of the sign.

I have created a slightly wider, thicker font as well.  I have to fix up some of the lower case characters, but when I get it finished I'll post the data for you if you wish to look at it.

Holtek sent an email back about my question regarding PWM and ghosting.  While one technician said PWM worked on a pixel-by-pixel basis, the second one said it's only per panel, which is what I seemed to discover.  Regarding the ghosting, they just said it was a problem with the "application circuit".  I think I'll try doing an LED_OFF, then updating memory, then an LED_ON and see what happens with that.

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