Button text is limited to 19 characters for button numbers less than 118 and 49 characters for button numbers 118 and up (SLCD+ is always limited to 19 characters).

The macros in the “macros_radio_button_ex.txt” file define a set of six buttons that act like radio buttons. Each button press calls an associated macro that sets the proper state for the button that was pressed and clears the state of the other buttons. The user would add application-specific commands to these macros.

When drawing a full-screen bitmap (.BMP) and using hotspots within it for control, the hotspots invoke macros. The macros redraw the screen. The colors being wrong is a side effect of how typical hotspots work. A standard hotspot defined by the “x” command specifies a touch-active area. When the area is touched, the screen is reverse imaged (foreground becomes background and vice versa) to provide visual feedback of the touch. When the button invokes a macro that redraws the screen, the screen is drawn while the button is pushed and the foreground/background colors are reversed. Then when the button is released, the hotspot is reversed even though the underlying image has changed. The solution is to use the “xs” command that does not change the screen when the defined hotspot is touched. The new screen will provide visual feedback, or the macro can do its reverse imaging.

See the “xset” command in the Software Manual (find the manual for your module from the Touchscreen Display Modules menu, in the Documents tab) for information on adding touch characteristics to a button or hotspot.

We recommend using the approach described in our In-System-Programming Application Note.

There are no provisions for storing application files on the SD card, except for saving screenshots and using the screenshot command for customer product documentation. The SD card is used for system updates since this is much faster than using the RS-232 port. Otherwise, our modules are intended to be human interface devices only.

You can use the Measure Tool in GIMP to get this information. Open your meter image with GIMP. Select the Measure Tool (it looks like a drawing compass) or select Tools->Measure. Click-and-hold the left mouse button on the pivot point and make a measurement straight down by the length of the needle. Release the click and get the needle’s zero point (angle). Now go back to the pivot point, hold the Shift key, click the left mouse button again, and move the pointer to the desired needle location. The Measure Tool will display the measured angle. Note: It will tend to keep the angle measurements less than 180 degrees, so you will need to do the math for larger angles. GIMP documentation for the Measure Tool See our video tutorial called “Design a Needle for the Meter Define Command.”

The “SET TEXT ALIGNMENT” command can control how the “TEXT DISPLAY” command places text on the screen. The following commands draw a rectangle, set the text alignment to centered horizontally and vertically, and draw a string centered in the box: r 100 100 300 150 ta CC t “Centered!” 200 125 Note: The horizontal alignment setting reverts to “L” after the text is written.

Connector J7 pin 10 may need a pull-up resistor to your host 3.3V supply and avoid a problem of the SLCD5’s 3.3V supply and your host 3.3V supply being different.

We recommend using a free program, Tera Term. To configure Tera Term for use with any SLCD development kit: Start the program, then choose: Setup -> Serial Port…, then set “Baud rate” 115200 (all other defaults are OK). Setup -> Terminal… -> Newline, the set “Receive” to CR+LF, and then check “Local echo”. In the main window, hit Enter, and you should see the “>” prompt.