It is well-known that photo, video and web content on a mobile phone is difficult to share with a group in settings where there is no other digital technology to upload it to. Yet these settings may have existing analogue televisions that could be used as public displays.
By filming the screen itself from an overhead camera and taking a sound feed from the headphone socket of the phone, Com-Cam is a low cost device for relaying the screen and sound of a mobile phone to an analogue television.
Cables from Com-Cam plug into the Scart or audio-visual sockets of a TV switched to its AV input channel setting. A number of different versions for the device have been tried. The best one includes an adjustable “lamp-like” structure with a whiteboard or chalkboard base.
The overhead camera is in the head of the lamp-like device which can be manually focussed, and moved up or down over the screen of any mobile phone which sits underneath. The mobile phone controls are left accessible while relaying the screen image at an appropriate scale to fill the TV screen.
The overhead camera also supports the use of Com-Cam as a whiteboard and overhead projector for making group presentations on a TV. Writing or sketching on the whiteboard or chalkboard base appears on the TV screen. Usefully this can also be done on paper for quick removal and replacement. Additionally, printed documents and other objects and materials can also be placed on the base for presentation on the TV screen, as with an overhead projector.
Com-Cam has a built-in microphone which can be switched on in these situations for amplifying the speakers’ comments through the TV speakers.
The electronic components of the device are readily available off the shelf in most countries and cost about £10. Our design shows how these components can be mounted on a simple lamp stand made out of local materials such as boxes and rulers.