Don't use "bitmap" property of TileGrid objects
In 8.0, the TIleGrid adds its own "bitmap" property. This interfered, causing the exception reported in guide feedback:
```
Traceback (most recent call last):
File "code.py", line 59, in
File "code.py", line 40, in __init__
NotImplementedError: Call super().__init__() before accessing native object.
```
@@ -36,15 +36,15 @@ for i, pi in enumerate((0xff0000, 0xff0a00, 0xff1400, 0xff1e00,
class RollingGraph(displayio.TileGrid):
def __init__(self, scale=2):
# Create a bitmap with heatmap colors
- self.bitmap = displayio.Bitmap(display.width//scale,
+ self._bitmap = displayio.Bitmap(display.width//scale,
display.height//scale, len(palette))
- super().__init__(self.bitmap, pixel_shader=palette)
+ super().__init__(self._bitmap, pixel_shader=palette)
self.scroll_offset = 0
def show(self, data):
y = self.scroll_offset
- bitmap = self.bitmap
+ bitmap = self._bitmap
board.DISPLAY.auto_refresh = False
offset = max(0, (bitmap.width-len(data))//2)
