Video Design Idea: Microcontroller drives 20 LEDs

By Staff -- 9/27/2007

This EDN Video Design Idea, presented by Dhananjay V Gadre, assistant professor in the electronics and communications engineering division of the Netaji Subhas Institute of Technology in New Delhi, India, details and demonstrates the use of "Charlieplexing" to drive 20 LEDs using six available I/O pins on an 8-pin microcontroller.

The circuit is based on an Atmel AVR-family ATTiny13 microcontroller, which features 1 kbyte of program memory; a four-channel, 10-bit ADC; and six general-purpose I/O pins. Altering the circuit's firmware allows linear or logarithmic scaling of the 0 to 5V input-voltage range.

Dhananjay V Gadre of the Netaji Subhas Institute of Technology in New Delhi, India, details and demonstrates the use of "Charlieplexing" to drive 20 LEDs using six available I/O pins on an 8-pin microcontroller.; AVR; Tiny13; led; microcontroller; video design idea; Dhananjay V Gadre of India's Netaji Subhas Institute of Technology explains how an LED can double as a photosensor and a visual indicator of ambient-light intensity.; EDN.com; led; microcontroller; sensors; video design idea; Bonnie Baker, senior applications engineer at Texas Instruments and regular EDN columnist, demonstrates a simple way to add DAC functionality to a microcontroller-based system using only an op amp and two passive components.; Bonnie Baker; DAC; EDN.com; analog design; op amp; video design idea; Mark Thoren, mixed-signal application engineering manager with Linear Technology, demonstrates an amplifier-based circuit design for a relatively inexpensive precision voltage source.; Mark Thoren; amplifier-based circuit design; linear technology; mixed-signal application; precision voltage source; Jim Williams, staff scientist with Linear Technology, explains why PC clocks are invariably wrong, and how engineers can surmount the extreme measurement challenge involved in solving the problem.; cell phones; computer clocks; jim williams; linear technology; nanoamps; quartz crystals; video design idea; EDN Tech Clips deliver technical depth and tutorial design information for engineers involved in analog circuit design, power management, embedded-system design, board-level design, signal integrity, and more. http://link.brightcove.com/services/link/bcpid1214067789http://www.brightcove.com/channel.jsp?channel=959007201

 

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