display.drawBitmap How can I use variable?

[makarna35]

Hi;

I have one more image:

`static const unsigned char PROGMEM i03n[] = { 0x00, 0x01, 0x80, 0x00, 0x00, 0x81, 0x83, 0x00, 0x01, 0xC1, 0x83, 0x00, 0x00, 0xC0, 0x07, 0x00, 0x00, 0xC7, 0xC6, 0x00, 0x00, 0x1F, 0xF8, 0x00, 0x00, 0x7F, 0xFC, 0x00, 0x38, 0xFF, 0xFF, 0x1C, 0x3D, 0xFF, 0xFF, 0x3C, 0x1B, 0xFF, 0xFF, 0xB0, 0x03, 0xFF, 0xFF, 0xC0, 0x07, 0xFF, 0xFF, 0xC0, 0x07, 0xFF, 0xFF, 0xC0, 0x07, 0xFF, 0xFF, 0xE0, 0xE7, 0xFF, 0xFF, 0xEF, 0xF7, 0xFF, 0xFF, 0xEF, 0x07, 0xFF, 0xFF, 0xE0, 0x07, 0xFF, 0xFF, 0xC0, 0x07, 0xFF, 0xFF, 0xC0, 0x03, 0xFF, 0xFF, 0xC0, 0x03, 0xFF, 0xFF, 0x80, 0x39, 0xFF, 0xFF, 0x38, 0x78, 0xFF, 0xFF, 0x3C, 0x30, 0x7F, 0xFC, 0x08, 0x00, 0x3F, 0xF8, 0x00, 0x00, 0x8F, 0xE2, 0x00, 0x00, 0xC0, 0x06, 0x00, 0x01, 0xC1, 0x07, 0x00, 0x01, 0x81, 0x83, 0x00, 0x00, 0x01, 0x80, 0x00, 0x00, 0x01, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00 };

static const unsigned char PROGMEM i04n[] = { 0x00, 0x01, 0x80, 0x00, 0x00, 0x81, 0x83, 0x00, 0x01, 0xC1, 0x83, 0x00, 0x00, 0xC0, 0x07, 0x00, 0x00, 0xC7, 0xC6, 0x00, 0x00, 0x1F, 0xF8, 0x00, 0x00, 0x7F, 0xFC, 0x00, 0x38, 0xFF, 0xFF, 0x1C, 0x3D, 0xFF, 0xFF, 0x3C, 0x1B, 0xFF, 0xFF, 0xB0, 0x03, 0xFF, 0xFF, 0xC0, 0x07, 0xFF, 0xFF, 0xC0, 0x07, 0xFF, 0xFF, 0xC0, 0x07, 0xFF, 0xFF, 0xE0, 0xE7, 0xFF, 0xFF, 0xEF, 0xF7, 0xFF, 0xFF, 0xEF, 0x07, 0xFF, 0xFF, 0xE0, 0x07, 0xFF, 0xFF, 0xC0, 0x07, 0xFF, 0xFF, 0xC0, 0x03, 0xFF, 0xFF, 0xC0, 0x03, 0xFF, 0xFF, 0x80, 0x39, 0xFF, 0xFF, 0x38, 0x78, 0xFF, 0xFF, 0x3C, 0x30, 0x7F, 0xFC, 0x08, 0x00, 0x3F, 0xF8, 0x00, 0x00, 0x8F, 0xE2, 0x00, 0x00, 0xC0, 0x06, 0x00, 0x01, 0xC1, 0x07, 0x00, 0x01, 0x81, 0x83, 0x00, 0x00, 0x01, 0x80, 0x00, 0x00, 0x01, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00 }; `

I can draw this image with: display.drawBitmap(0, 30, i03n, 32, 32, 1);

But I need use variable for draw images. Example I have this variable: String image_name = "i03n";

How to use this variable draw correct image simular?: display.drawBitmap(0, 30, image_name, 32, 32, 1);

[caternuson]

You can not pass in a string to drawBitmap: https://adafruit.github.io/Adafruit-GFX-Library/html/class_adafruit___g_f_x.html The bitmap will need to be stored as shown above. If you want the selection of the bitmap to be done using a string, you'll need to do that in your application code.

[makarna35]

If you want the selection of the bitmap to be done using a string, you'll need to do that in your application code.

I need this method.

[mzero]

@makarna35, I think you are going about your task in the wrong way. If you need to choose to draw one bitmap or the other at run time, do so like this:

bool drawAlternate = batLevel < 20;  // or however you decide which to draw
display.drawBitmap(0, 30, drawAlternate ? i04n : i03n, 32, 32, 1);

or if you have more states:

const uint8_t *b = nullptr;
if (charging) {
  b = i99n;
} else if (batLevel > 90) {
  b = i02n;
} else if (batLevel < 20) {
  b = i03n;
} else {
  b = i04n;
}
if (b) display.drawBitmap(0, 30, b, 32, 32, 1);

If you really need to base it on a string value - replace the conditions in those if statements with string comparisons.