Jogging Timer Schematic Circuit Diagram
Regular physical exercise is important, especially for those of us who spend most of our day sitting on the lab bench. Jogging is one of the most popular and effective forms of exercise, and it is important to have a systematic training regime.
That is where the jogging timer described here can help. Every ten minutes it emits a brief tone using its piezo buzzer and it indicates how many of these ten-minute periods have elapsed using a series of eight LEDs. Thus the electronics engineer on the jog can save him or herself the price of a special-purpose watch.
At the beginning of the training period, switch the device on and tuck it in your pocket. Since the device has an acoustic signal, there is no need to look at it to check progress, and you can devote your full concentration to your running. If you wish, however, you can glance at the display at any time to see how many ten-minute periods have elapsed so far.
The circuit is based on an Atmel ATtiny44 microcontroller programmed using BASCOM. On power-on it carries out a brief test of the buzzer and LEDs. A timer interrupt causes the 1 Hz LED to flash so that it is always possible to check that the timer is running, and at the same time a seconds counter is incremented. Every ten minutes a sound is produced using the buzzer and a further LED is switched on.
The BASCOM source code is available free at [1]. The code is easy to modify and the free demo version of BASCOM is adequate to compile it.
[1] http://www.elektor.com/110160