Nuts & Volts - January 2005

Stamp

The purpose of this code is to display a three-digit counter in the display, as well as run a little animated “bug” on the left. The main loop handles the counter. At the top of the main loop is a smaller inner loop that uses the Write command to send the counter digits to the display.

Notice how convenient the DIG operator is for us in this application. The next section animates the outside segments of the leftmost display. It’s a very simple attention getter.

Now that we have data in the SS8 buffer, we need to configure the display so that digits are shown on the right and the animated “bug” on the left.

With LOOKDOWN, we can determine how many columns the current count value occupies and, with that value, LOOKUP will give us the proper column mode and enable bytes. This lets us blank leading zeros and create a more professional looking display.

One of the things that you probably noticed is that the column mode and column enable bytes can — in some cases — be used to accomplish the same thing.

If I’m being honest, the column enable feature was a late addition to the project and this came after a lot of display experimenting. One technique that I experimented with while I was developing the code was prewriting to the display, and then revealing the display column by column by updating the column enable byte.

Well, it’s up to you now. I will admit that programming the SX — even with SX/B — can be challenging, however the rewards are really worthwhile.

If you use this display project as a guide, you can build any number of serial accessories that require buffered input. But be sure to download the SX documentation for the Ubicom, and please do check out the books I told you about; they will really make your journey into SX mastery far easier.