Usually I try to post only fully-completed projects in this blog, but this time I decided to violate this rule and post a link to a software library. Follow the link to a handy universal keypad library providing the following features (I’m copying verbatim from the site):

• keypad up to 8×8 or buttons up to 8
• fully configurable I/O : user defined ports, in keypad mode row port and column port may be different; user defined bits in port, user defined rows and columns number
• user defined character lookup table
• user defined erase and enter keys
• works on interrupt : no polling necesary, no key lost
• auto debounce, delay is user defined
• switchable typematic (auto-repeat) mode at run time, rate is user defined
• switchable linear/circular buffer mode at run time
• input is available at any time in a string buffer
• maximum input size is user defined
• other functions : last key entered / keypad status…

[ Project ]