Recently I wanted to expand the functionality of an automated test harness for an embedded device. The device has a 16 character display made of 4 Avago HDLx-2416 Series parts (datasheet). I gutted the device and tapped the display’s pins to my AVR. The AVR reads the LED display’s signal pins and sends the displayed string to the test harness via serial connection. Now the test harness can verify that the device under test’s display is lighting as expected. /* * ScreenScan.cpp * * Created: 6/8/2012 * Author: BK Turley */ /* port wiring: PB0 – ascii 0 PB1 – […]
I. Introduction / Summary The most practical way for a microcontroller to retrieve input is via interrupt. The vast majority of modern processors have interrupt functionality. This functionality allows a processor to work on background tasks while no input has happened. Once input is detected, the processor diverts its attention to react, then returns to where it left off after the interrupt has been serviced. II. Description and Circuit Diagrams An optical encoder is connected to VCC and ground to provide power to its internal emitters, detectors, and squaring circuitry. The encoders outputs are connected to P1 and P1 on […]
The clock signal is essential when designing sequential circuits, the following two code examples demonstrate how to produce a clock signal for your FPGA projects. These modules could also be used to produce square wave oscillations for other purposes such as audio tones.