The little project below implements a 2D bar graph on a single MAX7219. You can select whether the graph grows from the left side or the right side and you can specify how many rows and columns the graph will occupy - in case other LEDs are needed for unrelated annunciating. The lowest value LED blinks when the input value is zero as an indicator that the sketch is still running. Project is not locked so you can experiment with the settings.
Note: If the graph is less than eight LEDs wide the LEDs in columns not part of the graph are unusable since a whole eight bits are shifted into the display and masking data into the extra columns wasn't included.
