Code

Code

This folder contains the library code for driving the BUS terminal Signs.

For example code see ./Examples.

For documentation see the code file or online documentation.

Using code

The code should be placed in a folder inside the Arduino library folder. On my Windows machine that's C:\Users\brian.000\Documents\arduino\libraries\ConnectedHumber.

Alternatively, a symbolic link can be used. This way, code changes in the cloned repository are reflected in the Arduino library area. On Windows, you can do this using

mklink /D %USERPROFILE%\Documents\Arduino\libraries\ConnectedHumber %USERPROFILE%\Documents\GitHub\Bus-Terminal-Signs\Code

Protocols

At this point in time the code uses bit-banging to send the signals to the panel. I intend to include SPI at some point.

Notes

Note that the panels can be programmed when the display is off (see displayOn())

Commands that alter pixels do not change the display. You must call Panel.display() to update the panel, after setting the pixels.

Includes

Your code needs these includes:

#include <arduino.h>      # may not be needed in the Arduino IDE
#include <CH_AS1100.h>

Pixel array

uint8_t *pixels[8]; 

Each AS1100 chip controls 8 digit lines (rows) and 6 segment lines (columns). The six segment lines are stored in the pixel array hence it is an array of uint8_t. In order to accommodate variable length panels the array is organised as 8 rows of arrays of uint8_t of which only the 6 bottom bits are used - corresponding to the 6 segment outputs of the AS1100.

This arrangement has the advantage that the pixel array can be sent to the chips without alteration to speed up the sendPixels() method.

Adafruit_GFX

The library subclasses the Adafruit_GFX library and, as a result, it is possible to use the GFX drawing and text routines in addition to hardware specific routines.

NOTE: Adafruit routines often expect uint16_t not int data types, so you may need to cast ints to uint16_t like this:-

Panel p(...);
p.drawLine((uint16_t) x0,(uint16_t) y0,(uint16_t) x1,uint(16_t) y1,(uint16_t) color);

...or use uint16_t in your code.

Note the Adafruit_GFX routines expect a color argument. Since the panel LEDs can only be on or off this library sets the LED on if color > 0 and off if 0.