The market for portable applications is growing tremendously, specifically in consumer, medical, industrial, and military markets. In addition to display and storage functions, portable devices have one or more kinds of human machine interfaces (HMI) for the user to interact with the application. In newer portable devices, HMI interfaces such as alphanumeric or qwerty keypads, touch keypad/displays with white or color LED backlighting, programmable keys/switches, joysticks, scroll wheels, and buzzers/speakers are becoming more and more prevalent. Designers of portable applications face several design challenges which include rapidly changing HMI requirements, smaller form factors, and improved battery life. Actel's line of ultra-low-power, reprogrammable flash FPGAs provides solutions to address these challenges.
Using Actel's HMI solutions provides a host of key benefits:
- Actel's ultra-low-power flash FPGAs can be used to implement customized HMI controllers
- Actel's HMI solutions demonstrate integration of several control functions in a single, feature-rich, low-cost, and small form factor FPGA
- Reprogrammability allows for rapid development and fast time-to-market
- Ultra-low-power IGLOO devices with Flash*Freeze technology help reduce the power consumption of the overall system, resulting in increased battery life
- Design examples can be downloaded from the Actel website
- A network of solution partners meets your design needs
The block diagram above shows a design that implements multiple control functions on a single Actel flash FPGA device. This implementation can control the keypad, brightness of white LEDs, color mixing for red-green-blue (RGB) LEDs, and tone generation at the same time. The keyboard control interfaces with a 6x3 keypad (18 keys). This control also contains debounce logic for the keys. The design interfaces with the LEDs and speaker via pulse-width modulation (PWM) logic. An 8-bit PWM is used to control brightness and dimming functions.When interfacing with the color (RGB) LEDs, three PWMs are time-division multiplexed to drive multiple LEDs simultaneously as well as reduce power consumption. The tone generator logic interfaces with a speaker on the board via a 16-bit PWM. For more details on each of the HMI device controller and to download the design examples for each, please visit the HMI Daughter Card for Actel's Icicle Kit web page.
Actel offers a demonstration platform that showcases an IGLOO device as a controllers for various HMI functions. The platform consists of an
HMI Daughter Card for Actel's Icicle Kit. The HMI daughter card has a standard cell phone keypad with switches, white and RGB LEDs, and a small speaker.
