I²C interface for touch displays
They are available in sizes of 5-, 7-, 10.1- and 10.4-in. diagonal. "Compared with RS232, the I²C-based touch systems operate at high speed of 3.4 Mbit/sec and are extremely energy efficient with a supply voltage starting at 1.2V," stated Matthias Keller, COO Components at Distec. "The power consumption is extremely low. Therefore power supplies, batteries in handheld devices and the corresponding peripheral circuits can be very compact." This saves space, weight and cost through reduced cooling effort and also increases the life time due to the lower heat load of all components within the system.
An advantage of I²C is that there are no license fees required. This makes the I²C ICs significantly cheaper than USB or combined solutions. With the appropriate chip selection the costs can be reduced by another 30% without any sacrifice in functionality. On a project basis, other sizes currently up to a maximum of 24 in. can be implemented. For shapes, colours and logos there are virtually no restrictions offering a complete bespoke touch screen solution. To enable a professional and fast design-in support for the I²C hardware, Distec’s engineers have already prepared several implementations for various Linux kernel versions and for Android. Appropriate driver binaries, config files and sample scripts can be provided and adaptions to specific customer’s requirements are available.