LED POV DISPLAY PROJECT

Using Arduino Project Guidance
1

I have made a basic POV display using a Genie E18 PIC and 'BASIC code'. I am now looking to upgrade this by using an arduino mega. [I will discard the old project and start from scratch.] I am planning to put the system on a bike wheel. I am looking for some advice on how to know when the LEDs are at a particular position on the wheel. I have thought about using a hall effect sensor and a stationary magnet mounted on the bikes frame to do this. What I want to know is if there are other options that are more suitable or if this is the way to go. The sensor needs to react very quickly as the wheel will be revolving very quickly (around 1000rpm) and it must be precise.

Thanks.

2

The sensor needs to react very quickly as the wheel will be revolving very quickly (around 1000rpm) and it must be precise.

A bike wheel @ 1000rpm?
Like 16.6Hz? :astonished:

3

Yes a hall sensor is the best way to go on this.

Dont use a integrated hall switch , just get a hall transistor and do a bit if signal conditioning. it will be good for a few khtz

You need a fixed point of reference from which to start your display calculations.

A nice PID might also be good to soothe out minor fluctuations or even do a bit of predictive so that the display remain stable during acceleration an deceleration

Cheers Pete.

4

AWOL:

The sensor needs to react very quickly as the wheel will be revolving very quickly (around 1000rpm) and it must be precise.

A bike wheel @ 1000rpm?
Like 16.6Hz? :astonished:

A very fast motor bike with very small wheels perhaps :slight_smile:

5

Bainesbunch:
A nice PID might also be good to soothe out minor fluctuations or even do a bit of predictive so that the display remain stable during acceleration an deceleration

Excuse my lack of knowledge, but what is a PID / how do I set it up and use it?

6

Bainesbunch:

AWOL:

The sensor needs to react very quickly as the wheel will be revolving very quickly (around 1000rpm) and it must be precise.

A bike wheel @ 1000rpm?
Like 16.6Hz? :astonished:

A very fast motor bike with very small wheels perhaps :slight_smile:

Yeah I am using a bike wheel to model the system. A motor will be used along with a gearing system to spin it.

7

Check this out: Spoke-o-dometer Overview

http://www.openobject.org/opensourceurbanism/Spoke-o-dometer_Overview

8

jconnolly996:

Bainesbunch:
A nice PID might also be good to soothe out minor fluctuations or even do a bit of predictive so that the display remain stable during acceleration an deceleration

Excuse my lack of knowledge, but what is a PID / how do I set it up and use it?

Try goggling it first, then if you dont understand it come back to me.

9

steinie44:
Check this out: Spoke-o-dometer Overview

http://www.openobject.org/opensourceurbanism/Spoke-o-dometer_Overview

This is extremely helpful, thanks very much!

10

If I am to use a bluetooth shield along with this to allow wireless rewriting of the display message, would this mean that I will have less inputs and outputs available from the arduino?
Or is there a better way of wirelessly communicating with the arduino in order to change the message?

11

Bainesbunch:

jconnolly996:

Bainesbunch:
A nice PID might also be good to soothe out minor fluctuations or even do a bit of predictive so that the display remain stable during acceleration an deceleration

Excuse my lack of knowledge, but what is a PID / how do I set it up and use it?

Try goggling it first, then if you dont understand it come back to me.

I've googled it and don't really get how to integrate it into this. Could you provide me with a link to somewhere that will explain it?

12