Just like a PC’s USB port, the serial port on a PC can also in some cases serve as a power supply. A USB port can provide as much as 500 mA at 5V, but a serial port provides less power. Even with the ...

Seven-segment displays are needed in many instrument designs. In conventional microcontroller-based designs, four output port lines are allocated for one seven-segment display. Figure 1 shows the ...

Although 8051-compatible microcontrollers with SPI ports are available, a lower-cost device with an SPI port bit-banged through GPIO pins often suffices. The code shown here takes advantage of ...