I have a 8x1 LCD, 18F2520 microcontroller, Crystal 12 MHz, buttons and pressure sensor. Normally it is working good. But When I bring the WALKIE TALKIE, the display values keeps changing. Is it because of the frequency from the WALKIE TALKIE affects the microcontroller?
Is it EMI/EMF interference? How to solve this issue.
The wiring in your device is working like an antenna. The voltages it picks up from the transmission are enough to upset the digital signals around the MCU. We would have to see your construction to advise but basically it comes down to screening it and if necessary adding low-pass filters to external input wiring.