ECE 4760: Final Project

A Wireless Programmable Pace Clock

with Android Bluetooth Control

Paul Swirhun (

Shao-Yu Liang (

"A wireless pace clock controllable and programmable via an Android mobile application over Bluetooth."

project soundbyte

For our ECE 4760 final project, we designed and built a wirelessly programmable digital pace clock with a large format LED display and Android smartphone control and programming.

This original design achieves the functionality of commercailly available pace clocks but with an intuitive user interface that goes beyond anything that is available in the current marketplace, all at a small fraction of the cost.

The clock runs from an Atmel ATmega32A microcontroller and a host of peripheral integrated circuits with a Bluetooth connection to an original Android smartphone application to configure swimming workouts, timing intervals, and real-time wireless control of the clock's features.

The finished product.

The designers.

A Background on Swim Training and Pace Clocks    top

A pace clock is a large format clock used to time intervals in athletic training, most commonly in swimming or track. Modern pace clocks are large format 4-digit LED displays, with either a grid or 7-segment layout. Swimming workouts are typically organized in advance of a swim practice and include a series of different strokes and drills at various speeds and of various distances. The interval timing can be done with a single count-up clock display, requiring the swimmers and coaches to calculate the appropriate start times and estimate their pace mentally by following a clock. Alternatively, as many proactive collegiate swim coaches do, the day’s or week’s workouts may be programmed into a programmable pace clock to automatically time the swimmers’ sets. This means, for example, that the clock would either count up-to or down-from the interval time (eg. 1 minute and 20 seconds) and then move on to the next interval. This improves workout efficiency by ensuring that the swimmers start the next set on time, and that they receive accurate feedback about their performance and pacing.

An item within a workout will convey to the swimmer (usually in this order): the number of repetitions, the distance, the stroke with optional comments, and an interval. For example, a swimmer might see the following item in a day’s workout:

10x 100 Fly (50 Drill/50 Swim) on 1:50

This indicates the swimmer must swim 100 yards (or meters, depending on the pool) of the butterfly stroke 10 times, on an interval of 1 minute and 50 seconds, with the first half of each 100 being a butterfly drill and the second half being the standard, full stroke. A pace clock makes this timing possible, and a programmable pace clock makes it easier by counting up to 1:50 (which allows swimmers to see their pace as they finish each 100) or down from 1:50 (which allows swimmers to quickly see how much time remains before they must start the next 100 fly).

Swimming workouts are structured with repetition, loops, and variable intervals, basically a series of the above items that may appear as the repetends of loops. Loops may also appear in the repetends of loops. There are thousands of workouts which can be found online for further clarification.

Pace clocks are expensive and can be cumbersome to use for those not willing to learn their operation and programming method. One of the leading companies selling pace clocks is Colorado Time Systems. A wirelessly programmable pace clock such as the one we have designed and built costs roughly $900-$1400, not including the programmer which costs $440 and is required for programmable workouts. There are additional features on these systems which we did not intend to implement. These may account for some of the difference in expected price between our design ($75 maximum) and the $1k-$2k commercial systems. These differences include battery operation, multiple screen-controlling with a single ($440) controller, and standard interfacing with a much larger product line, including race-accurate timing pads for competition. Many swim teams, particularly in summer swim leagues, cannot afford such elaborate timing systems and cannot justify a fully integrated race timing solution since they rent time at public pools and use rather low-tech timing solutions for races: parents equipped with stopwatches.

"This would be extremely beneficial to competitive swimming at all levels: 'age-group' to collegiate!"

Christaina DiMaria, Cornell Swim Team Captain

By designing a wireless, programmable pace clock in the price range of smaller swim programs, and enabling its wireless control through a Google Android Smartphone App, we have produced a viable product with a much broader buyer market than the currently available commercial systems. To our knowledge, no such product exists at this time. The coupling of a Android-based controller (and its intuitive, simple interface) with reliable and cost effective microcontroller operation can vastly improve the cost effectiveness and usability of these training tools to make pace clock timed workouts accessible to more athletes.