When we see oscilloscopes, we would like it to have a big colored screen – well most oscilloscopes in the past has a green image with moderate screen size. Most modern scopes however come with large colored graphics LCD displays which inherently make wave viewing more coherent. But this doesn’t mean that 4×16 and 2×16 LCDs can’t be used as oscilloscope displays.
Bruno Gavand demonstrates just how to use a PIC18F4620 along with a 2×16 LCD to implement an oscilloscope. Bruno’s design was very simple and straight forward, an analog input pin was used for the probe, and the PIC will take ADC readings and then displays the results and a mini-graph will be displayed in the LCD.
Some drawbacks that we observed is that one the graph is too small it doesn’t give much detail about the waveform, two the input is single ended thus prone to noise and three no signal conditioning at the input. It might have design limitations but it sure showed us that implementing an oscilloscope in a text type LCD is possible.