He also added a low-pass filter and a comparator to clean up the signal into a nice square wave, ... [Turi] built a 5×5 button matrix for inputs and paired each to one of the diodes, ...

For example, a programmable second-order, low-pass Butterworth filter with a corner frequency ranging from 200 Hz to 20 kHz can be designed by setting C1 = 0.022 µF and C2 = 0.1 µF.

Microcontrollers are digital devices at heart. They can do fancy things like convert analog signals into a digital value but going the other direction is a bit tougher. Pulse-Width Modulation is us… ...

Santa Clara, Calif. OnChip has introduced a family of EMI low-pass RC Pi filter arrays with on-board diodes for ESD protection. Additionally, they have built-in Zener diodes that protect the LCD ...