RE: Smarter Life Challenge: Smart Bicycle Light (update #1)

vsluiter — Sun, 03 Nov 2013 22:04:19 GMT

Anthony,

Today I also suggested to use a digital Accelerometer / Gyro (MPU9150 even has a Magneto on board). Most of those even have a low power mode which still give interrupts when movement has been detected. That will free up some analog inputs.

As DAB mentioned, the LDR might work fine. With the on-board opamps, you might even create an 'anticipator' circuit (actually wrong naming, but it's a circuit that speeds up settling if you know the time constant of the LDR). One description can be found here: Simple anticipator circuit improves on earlier idea | EDN

RE: Smarter Life Challenge: Smart Bicycle Light (update #1)

DAB — Wed, 30 Oct 2013 19:36:09 GMT

Hi Anthony,

You have a nice challenging project here.

You might want to consider using a fuzzy logic filter to help determine a transition from night to day.

Do you need to consider riding under trees or going into tunnels? A light sensitive resistor might work just fine, you may just need to be a little creative in writting the code to sample the light intensity and then decide at what point of falling light you want to trigger the device to your dark state.

You might also consider your timeline for going from light to dark mode. Think about the issues involved with the transition and the response time you want to support.

Looks fun,

DAB