Is there a simple way to clear text before writing new string

[PaulM47]

Hi, I'm really impressed with this software, it works well. I'm using it for a clock/calendar display spread over 2 x 64 x 32 panels.

I hopefully have a simple question. If I write a text string to the panel using 'dma_display->print(text[color])' it simply overwrites any text that was already displayed, e.g. updating hours, minutes, seconds etc.. I tried simply writing a space character, but the software appears to only change illuminated pixels, it doesn't extinguish those not needed. Is there a simple way to clear previous text before writing new, or do I need to do something like drawing a black filled rectangle first to blank out the old text ?

PM

[board707]

do I need to do something like drawing a black filled rectangle

I think this is easiest way to clear the text.

[davemaster]

print a "background" (color) text before the new, or check if the second is the same of the "second" before; if diffferent, print new value

[PaulM47]

Solved this one, character code 218 is a full block, write in black and it removes any previous characters.

Code snippet that works with the colorwheel example -

`// write character array 'text' to dislay at xpos, ypos
// clears characters before writing

dma_display->setCursor(xpos, ypos); // set cursor position
dma_display->setTextColor(myBLACK); // change colour to black
for (uint8_t x = 0; x < strlen(text); x++)
{
dma_display->print((char)218); // write black block to display
}
dma_display->setCursor(xpos, ypos); // set cursor position again
for (uint8_t x = 0; x < strlen(text); x++)
{ // draw characters using colorWheel
dma_display->setTextColor(colorWheel((color*32)+offset));
dma_display->print(text[x]);
}
`