The Design Idea in Circuit and software provide accurate recalibration for baseline PIC microcontroller's internal oscillator uses three I/O lines to recover the internal calibration value by recalibrating against a reference clock, the 4-MHz crystal.

The method in Microcontroller moving-dot display interface uses three I/O lines needs three output lines—data, clock, and latch—and requires some firmware and hardware. The moving-dot display has some benefits over the bargraph display: It better indicates a location of detected object in sonar and radar applications; it needs only one LED's current-limiting resistor instead of several; and it provides the same current for all LEDs, thus providing even brightness.

Using the scheme in Microcontroller displays multiple chart or oscilloscope timing ticks you can add time ticks, representing seconds or minutes, to a chart graphic by using a simple and inexpensive crystal based microcontroller to generate a sequence of tags on a dedicated chart channel.

The circuit in Fast-settling synchronous-PWM-DAC filter has almost no ripple avoids most of the problems of lowpass filtering of the output of a high-resolution DAC by combining a differential integrator in a DAC-output span with common voltage references.