Circuit Lake

Electronic Project and Circuit Collection

Mini Train Stop Alarm, Station Master

12/04/2010 Category: Alarm, AVR, Microcontroller, Project

The Station Master is a small key ring sized alarm that uses an accelerometer to track your movement. The device will gently vibrate and let you know when you’ve reached your stop and it’s time to disembark from the train. Using a simple one button interface the user can set an alarm for the right number of stops and then be reminded when its time to get off.

train stop remainder

Nick Lott, the project designer, uses MCU AVR ATtiny13 as main processor, An MMA7260 3-Axis Accelerometer to monitor the tilt and movement of the device, and cell phone’s alarm motor as discrete silent alarm. The system produce sine wave to give the alarm a really natural look and feel when using either an LED or motor for output.

train alaram block diagram

How it works?
The overall system operation is very simple. Data is read from the pushbutton and the accelerometer and then once certain conditions are met the cell phone motor is gently pulsed with a sine wave. Clicking the button wakes the device and adds a stop to the alarm counter while holding the button for one second disables the alarm and puts the device to sleep.