PDA

View Full Version : Speed warning project for motorcycle



ywfbi
07-27-2005, 07:53 PM
Good evening to all, Im a newbie to the world of stamps and am starting a project. Im not sure if it can be done with a stamp, seems like it could be a bit big but Im not sure.
I was also considering a PLC, but I really want to keep it as small as possible so thats why Im here.
Ive detailed exactly what I want it to do in a attached PDF, if you get some time please have a look. Any advice would be greatly appreciated!

Regards

Post Edited (ywfbi) : 4/18/2006 10:46:09 PM GMT

Bruce Bates
07-27-2005, 09:39 PM
Dean -

Probably the most straightforward method of detecting the ground speed is with an OEM GPS unit which produces the NMEA Sentence $GPVTG whose sub-parameter 7 is KM/HR.
By continually fielding that sentence, you will be able to keep track of the current speed over ground, without relying on anything connected with the motorcycle. Thus, any variabilty there in the motorcycle (gearing, tire size, etc) is superflous to the method.

The tacho function can be obtained by a Hall Effect sensor sensing some rotating element of the motorcycle which is proportional to the rotational speed of the engine.

The rest seems to just be a matter of reading some pushbuttons, and lighting some LEDs based on the readings gathered.

I would expect all of this could be accomplished with either a Stamp BS-2SX or Stamp BS-2px. Very interesting project, good luck with it.

Regards,

Bruce Bates

Larry~
07-27-2005, 10:16 PM
There might be one more thing you should add to your specs,

It would also be nice to have a cal for the speed so if/when

changing tire/wheel size the unit can be recalibrated for that

size. I have done a spedo with calibration using a automotive

electronic pickup off the final stage of a transfer case 4x4 and

a second one using a (hall effect sensor) off the drive shaft.

both units had spedo, odo, saved values to eeprom, and I think one

displayed time also.

ywfbi
07-28-2005, 05:14 PM
L_Gaminde said...

There might be one more thing you should add to your specs,

It would also be nice to have a cal for the speed so if/when

changing tire/wheel size the unit can be recalibrated for that

size. I have done a spedo with calibration using a automotive

electronic pickup off the final stage of a transfer case 4x4 and

a second one using a (hall effect sensor) off the drive shaft.

both units had spedo, odo, saved values to eeprom, and I think one

displayed time also.


Good thinking with the calibration, I had also decided it to be a nessicity since the pickup is off the output shaft of the engine it will need to be calibrated each time a drive sprocket is changed. Tyre size on bikes is rather fixed, and difference between new and worn tyres is negligable, but future compatability is the difference between a good project and a great one!
I see you have done simalar project before, it would seem to me that the trickiest part of the project is getting the speed measurement and calculation aspects correct, if I could I'd love to learn from your experience in the matter. Could you please email me some details of what you did and how you implemented the project onto a stamp? It would be·greatly appreciated.



Post Edited (ywfbi) : 12/13/2005 9:12:40 AM GMT