People’s constant need to communicate with each other has been served since ancient times by various solutions ranging maybe from horse riding messagers to the nowadays omnipresent mobile phones or the internet. One particular field of communication relates to the situations when someone visits another person located into a building, and that visitor needs to signal its presence at the entrance of the building. Our technical solution here was the video door phone.
By its definition, the video door phone is a stand-alone system used to manage calls made at the entrance of a building (villa, residential complex, office building, etc.) to all indoor connected terminals. Our solution supports both analog video and audio communication.
The entire system’s backbone is based on our own internal design, in terms of behavior, electrical specifications and data bus type. It is using a single wire (non-differential) CAN bus up to 256 nodes and the same bus line to transmit video and audio data. We had to design an asynchronous system that deals with multi-point node communication over long range wires (up to 300 meters long).
For this video door phone communication solution we had to mix a full flavor set of technologies like CAN bus system, RFID tokens, touch sense buttons (CVD, CTMU and CSM) and serial interfaces like SPI, I2C and UART.
