All PSoC Application Notes

AN2034: Keypad Scan, PSoC Style

X–Y matrix keypads are an inexpensive interface allowing interaction with microcontroller-based products. The ideal keypad-scan routine should be fast and use minimal RAM resources. It should also be able to operate in a polled or interrupt mode. This Application Note shows how, by exploiting the PSoC microcontroller’s unique I/O structure, a keypad-scan routine can be built that meets these requirements. A function callable by either ‘C’ or assembly language is also presented