Commandments for using PIC Microcontrollers
Based on his working experience with PIC microcontrollers, John Chandler has summarized some basic rules that could minimize the project development time and increase the reliability of PIC operation. Some of these rules (he said commandments) are related to power supply, clock and reset operation and hence they are applicable to all PIC circuits. Some PIC microcontrollers have multiple pins for Vcc and ground. He suggests to connect all of them not just one pair. A 0.1 uF bypass capacitor must be connected closest to the microcontroller. Similarly, the MCLR pin must not be floating, if it is enabled. Read more at digital DIY.