Multi Digit Display

How can I get a multi-digit display from RSR Electronics to work with an Arduino?

It appears to be a normal seven segment display: Or check out the playground for more examples.


how many are you trying to use? and what Arduino platform are you using as well?

You may need 'more pins'.. so using a shift register chip might be an option for you as well.

Up to 4 digits I would multiplex them, using one transistor per digit to drive the common anode or common cathode, and driving the segments directly from Arduino pins through common series resistors. This uses 7 pins for the segments (or 8 if you are using the decimal point), plus 1 pin per digit (you can reduce this if necessary by using an external demultiplexer chip, e.g. 2 pins for 4 digits). For more digits than that, or if I need to use fewer pins, I would use shift registers or specialist 7-segment display driver chips.

The digit pins can be used to multiplex other devices at the same time, for example I use them to multiplex rotary encoders and push buttons to reduce the number of input pins I need.

I've updated this library for Arduino 1.0 and added support for Hex (actually any arbitrary base up to 16). David Kaplan's site has been down so I am hosting this on my site so it does not vanish altogether.