Design in distributor GD Technik has developed a LCD driver board for a major brewing equipment manufacturer in Tyneside.
Design in distributor GD Technik has developed a LCD driver board for a major brewing equipment manufacturer in Tyneside. The company used off-the-shelf components to build a tailor-made board to drive a graphical user interface (GUI) for a brewing process controller, providing the optimum cost effective solution in record time. The GUI components comprise a 5.7in monographic quarter VGA display combined with a touchscreen interface.

The display features a back lit cold cathode fluorescent tube (CFL) and transflective screen technology, providing low-power consumption, yet bright and sunlight readable display.

As well as supplying the GUI, GD Technik needed to design, develop and test a working driver board to mount at the back of the display, which interfaces with the microprocessor-based brewing process controller.

To link the display module with the brewing process microcontroller is an Epson S1D13305 graphics controller, which provides data and control signalling together with control and access of stored data in the driver’s 64Kbyte of SSRAM.

While the driver board requires a 5V power supply, the BIAS PSU generates locally the -24V power supply for the LCD.

Power sequencing is controlled by an Atmel 8bit AVR RISC microcontroller, which also provides in-system-programmable Flash memory.

A particularly important feature of the circuit, improving reliability is an optional self-test unit, facilitating testing during manufacture.

One of the most important challenges facing GD Technik’s design team was to interface the touch screen to the brewing process microcontroller.

The company’s engineers turned to Atmel’s AVR microcontroller, programmed to scan the touch screen via its I/O ports and convert the information into five-packet-protocol, demanded by the customer’s microcontroller’s serial interface.

After successful delivery of this custom solution, GD Technik has found further interest from the market place and is currently working on a colour LCD version of its GUI driver.