Persistence of vision wheel

[Dave]

An accelerometer and an a/d channel if the wheel is turning purpindicular to earth's gravity.

[ardhuru]

This is a typical 'propeller clock' type application. You will need to use something to determine not just the RPM, but also to know when to begin displaying your frame per revolution, or else your graphics would get garbled.

You can easily use IR to generate your index pulse; Mount the continuously lit IR LED on the chassis, and an IR detector on the spinning platform. Align them such that they see each other once every revolution.

Regards,

Anand

[rsocor01]

You can easily use IR to generate your index pulse; Mount the continuously lit IR LED on the chassis, and an IR detector on the spinning platform. Align them such that they see each other once every revolution.

Or mount both on the chasis in such a way that the spinning LEDs will block the path between them once every revolution and you are set.

[ardhuru]

No, that wont work. The information that the beam has been detected/broken is needed on the rotating assembly. Getting that information on the fixed chassis will serve no purpose.

Anand