25 functions for 25 cents: timer functions


Have you ever found yourself asking, “Where did the time go?” If you’re like me, you probably ask yourself this daily.

Keeping track of time is very difficult; luckily, timer modules on an MSP430™ microcontroller (MCU) are created solely to do this very task. From kitchen timers to home security systems, timers are at the heart of many things we use. TI’s MSP430 value line MCU TechNote series includes a timer functions category.

The series shows how you to implement timer-based solutions on TI’s low-cost value line MSP430 MCUs, all implemented using a memory footprint of 0.5KB for the MSP430FR2000 and 4KB for the MSP430FR2111. TechNotes showcasing different applications of our timer function technology include:

In many instances, timers dependably give data about the current time of day, especially in battery-operated devices. Consider a smart smoke detector in a household. Smoke detectors are expected to run off of a battery for years at a time. They are also expected to have a sense of the current time and date in order to track threat levels and alert consumers if they detect a trigger. Through the use of an MSP430 MCU’s real-time clock (RTC), which uses the timer module, a smoke detector can accurately log time stamps of events and notify consumers of the exact time of a smoke detection.

Another purpose for an MSP430 MCU timer is to add precision to a system in regards to measuring time. An Olympic coach’s stopwatch needs to be incredibly precise in order to accurately measure a sprinter’s time. If the increments of time are off even by the slightest fraction of a second, the time recorded for a 100m dash will be drastically incorrect. Through the use of accurate clocking systems and/or external crystals, our MSP430 MCU timers can precisely measure time passed so that even Olympic coaches can faithfully rely on their stopwatches. Figure 1 depicts how to use a value line MSP430 MCU to make an accurate seven-segment light-emitting diode (LED) stopwatch.

Figure 1: Seven-segment LED stopwatch block diagram

Timers typically have two different modes of operation: compare and capture. Compare mode generates signals and triggers events in a pre-determined time interval, while capture mode records a time stamp of an event or signal. Using these two functions, timers have revolutionized the way personal and industrial devices can store, analyze and track time. These are only a couple of examples of how timers can solve everyday problems. With a little creativity and ingenuity, anyone can find the next best timer application.

Every timer function promotes the low-cost MSP430FR2000 MCU, which alongside other MSP430FR21xx devices is available in a 16-pin thin-shrink small outline package (TSSOP) and a 24-pin very thin quad flat no-lead (VQFN) package.  With a price as low as 25 cents for orders of higher volumes, our value line MCUs provide a cost effective and robust solution to replace today’s application specific integrated circuits.