My company is developing and producing measurement devices. To quality check and adjust the full devices automatically, we need to be able to read the display indication and trigger functions like high resolution, zeroing, etc.
We are using usually the built-in communication interface (RS-232, WiFi, Ethernet). However, cheaper variants do not have a communication interface except the buttons and LCD display for the customer.
Reading would be possible with OCR, but pressing the various buttons with a robot hand (morse code or similar) is even more "complicated".
To keep product cost low, we are thinking of having a more or less hidden connector with a MCU UART connected to it directly.
Personally, I'm wondering if it would be even cheaper and more convenient to connect a processor pin to a medium sized tiny PCB antenna. Then try to use an UART or bit-banging to "radio" out signals, basically to intentionally cause low-frequency EMI. Outside of the device under test, there is a very close and big antenna for receiving the signal. I assume trigger functions in the device is the harder part.
Is this a viable idea? Can you point me to a term or solution I can further research? Thank you very much!