Example: Keypad library with buffer and fn key support
We present here a complete keypad library for the 8051 family. The library has support for function keys (two) and has a buffer facility. The library is intended to work with key- pads as shown in Figure 20.3, but is easily adapted to different keypad layouts and sizes.
The demonstration program runs on an Infineon c515c microcontroller. However, none of the keypad code is 515 specific: using appropriate versions of the scheduler and the PC link libraries (included on the CD) it can be used with any 8051 family member.
Figure 20.4 shows a typical program output.
The key library files are given in Listings 20.2 to 20.5. Refer to the CD for the com- plete set of files for this example.