Lap Timer Phase 1

Cycle speedway and many other activities are suspended at the moment and so Charlie Parr has determined to fill some of his time by learning the Python computer programming language.

Charlie already has a little knowledge of programming having used Scratch at school, but learning a serious programming language such as Python, would be a new and beneficial experience.

Learning any language, whether it be a foreign language or a programming language, can be a time consuming, difficult and frustrating experience; to help overcome these, a project was chosen having a useful goal, providing a target to aim at and a sense of achievement on completion. Thus the development of a cycle speedway laptimer was commenced.

Specifications of the project:

1 – The timer should only deal with one bicycle on the track at a time
2 – The timer should start when a laser beam is broken by a bicycle tyre
3 – The elapsed time should be displayed on a Liquid Crystal Display (LCD)
4 – The completed lap time should be displayed when the laser beam is broken again
5 – The timer should continue to time subsequent laps
6 – The timer should be battery powered

Hardware required to build the laptimer:

Raspberry Pi (RPi) – computer to run the software
PiFace Control And Display (PiFaceCAD) – LCD screen
Laser pen
Photoresistor – reacts to a break in the laser beam
Battery holder
4 x AA batteries

The RPi, PiFaceCAD and Laser pen were already available and the photoresistor was bought for £2.35. The batteries and battery holder have not yet been acquired.

The Rpi is an ideal computer for many projects as it is cheap, portable and with the ability to be converted to battery power. The PiFaceCAD plugs directly into the RPi and includes an LCD and push buttons which will be used to control the timer.

In order to have tangible results as the project develops, the decision was taken to divide the project into phases. The first phase was to build a stopwatch using the PiFaceCAD buttons to start and stop the timer. Further phases of software development will introduce a laser to control the timer and also converting the Rpi from mains to battery power.

The initial phase of development is complete and Charlie now has a working laptimer/stopwatch; he is pictured holding the PiFaceCAD mounted on top of the RPi.

Development is set to continue in the coming weeks and an update on progress will be published in due course.

The software developed so far is listed below: