It’s no secret that the era of landline phones is slowly coming to an end. As of 2020, it is estimated that less than half of households in the United States are still subscribing to Plain Old Telephone Service (POTS).But of course, this is still millions of subscribers, and they may get from his Caller ID developed by Arduino [Dilshan Jayakody].
To be honest, so far, we have not really considered the working principle of the call-in display system.But as [Dilshan] Explain that you can actually pick up a dedicated IC that can decode incoming call data sent over the phone line. In this case, he used Holtek HT9032D, which was packaged in a through-hole DIP-8 package and sold for approximately US$2. The chip needs some passive components and a 3.58 MHz crystal to help it complete its task, but other than that, it is actually just a matter of reading decoded data from its output pins.
To display the caller’s information, [Dilshan] I am using Arduino Uno and ordinary 16×2 HD44780 LCD. As a good touch, the code will even flash the Arduino’s onboard LED when you miss a call. As a proof of concept, no attempt was made to compress the hardware or abandon the breadboard, but it is not difficult to imagine that if you want something more durable, all the components can be packaged in a beautiful 3D printed enclosure.
We have seen caller ID data collected in previous projects, but they used a combination of USB modem and software methods. We really like the idea of using cheap dedicated ICs to do this, although we admit that this demo might have been more exciting ten years ago.