Human-machine interface design

Paul Boughton

Designing human-machine interfaces (HMIs) such as industrial touch screens has now been made easier with the launch by Alpha Micro of the FTDI VM800B and VM800C development modules designed for use with the integrated FT800 EVE embedded video engine.

The VM800B is supplied with the PCB pre-installed behind a display with a bezel. The displays are offered in 3.5-in, 4.3-in and 5-in sizes, with a choice of black or pearl bezel and a bezel mounting kit. The VM800C is the basic development module which is supplied as a credit card sized adapter board which can be purchased with or without a display (but no bezel).

EVE has totally changed the way that engineers create human machine interfaces (HMIs) on QVGA and WQVGA based TFT displays. Thanks to a unique object-oriented approach, it allows more advanced HMIs to be realised across a broad spectrum of application areas - with display, audio and touch functionality all included. Furthermore, it manages to do this while minimising the bill of materials costs, lowering the PCB space required and shortening the development process normally associated with such implementations.

The VM800C module, which utilises a highly integrated FT800 EVE graphical controller IC, is offered with a choice of 3.5-in, 4.3-in, or 5-in format LCDs. A 4-wire resistive touch screen is integrated onto the specified LCD. The module also supports mono audio output with an on-board audio power amplifier and a micro speaker both included. It can be powered at 3.3V or 5V through either a 2.1mm power jack, a SPI master connector or via its USB Micro-B port. The module has a standard SPI interface so that any microcontroller with this commonly used IO can be easily connected with EVE technology.  Similar in functionality to the VM800C, the VM800B systems are offered with the same screen size options. The primary difference is that the display and PCB are designed to securely fit into a plastic bezel encasement, with easy access to power and interface ports. It is offered in either a black or pearl finish.
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