Mastering rotary encoders - Part 2

摘要

IN the past few months there have been a couple of threads on the EPE Chat Zone relating to rotary encoders. Last month, Lincoln asked about a budget (65p from Alps) three-terminal rotary encoder to advance or retard counters in a PIC circuit. In his circuit, one of the encoder outputs interrupts the program and the interrupt then reads the other pin to see if the encoder has been turned forwards or backwards, which in turn raises an appropriate flag. He found that the counting was not always working the way he wanted; he tried software debouncing and adding capacitors, but felt that these solutions were not ideal. Lincoln also asked about the advantages of more expensive rotary encoders and if he needed to raise the clock speed of his PIC.