Looking for a sensor or devise, that indicates a forward and a reverse movement

They use gyroscopes for this purpose in the aviation industry. Alternatively, have you thought of a pendulum suspended on a rigid arm, but pivoted so that it is free to move at the top. Any change in speed or direction will cause movement of the pendulum relative to its mountings, and you would need to devise a system of coils attached to it and moving in a magnetic field to generate a voltage proportional to the movement

Harry Pfeifer

Does anyone know of a devise or sensor that can indicate a signal or no signal for a forward movement, but have a signal for a reverse movement? Or is it impossible to do? I am open to any other solutions that someone can tell me

Description of project is that

1. It has a flat surface to mount to
2. It has wheels for mobility for the movement of a forward or reverses (push or pull)
3. Power supplied 12v DC 20amp
4. To be used for out-door use, subject to extreme weather conditions and temperatures.

Example: Take a child's red wagon being pulled or pushed in different directions. Pull the wagon towards you and walk "prefer a signal Stop "prefer a signal Push the wagon backwards "signal " Now pull the wagon towards you and walk "prefer a signal

The specs should fall into this area Sensor Specifications:

1. Bi-Directional
2. 1-3 phase signal, reverse motion and stationary (non movement)
3. Generate a signal reverse or opposite direction from a forward motion
4. Time delay adjustment
5. Temperature rating -40°C - +50°
6. .5v - 12v DC .01amp
7. Sealed unit
8. Weather proof
9. .002% accuracy
10. Vibration tolerance adjustment
11. To be used in an external application only
12. No moving parts or external reference
13. Non magnetic
14. PC programmable

Something like a digital compass? I'm not that experience in this field

Hi, try the analog devices accelerometers. The adxl203 may suit. +/- 1.7g dual axis +/- 4% accuracy.

You can use one axis to tell if you're on an inlcine and the other for forward/reverse motion. The 1st can then also be used to compensate for incline to tell you information about the rate of motion in fwd/rev. (velocity)

You can then integrate that information to tell distance travelled etc.

If you're not interested in forward motion, then your software would just ignore data that indicates forward motion.

If you don't want to use software then a comparator could be used to give a "1" or "0" based on the velocity threshold you set up.

hope that helps Greg

Does anyone know of a devise or sensor that can indicate a signal or no signal for a forward movement, but have a signal for a reverse movement? Or is it impossible to do? I am open to any other solutions that someone can tell me

Description of project is that

1. It has a flat surface to mount to
2. It has wheels for mobility for the movement of a forward or reverses (push or pull)
3. Power supplied 12v DC 20amp
4. To be used for out-door use, subject to extreme weather conditions and temperatures.

Example: Take a child's red wagon being pulled or pushed in different directions. Pull the wagon towards you and walk "prefer a signal Stop "prefer a signal Push the wagon backwards "signal " Now pull the wagon towards you and walk "prefer a signal

The specs should fall into this area Sensor Specifications:

1. Bi-Directional
2. 1-3 phase signal, reverse motion and stationary (non movement)
3. Generate a signal reverse or opposite direction from a forward motion
4. Time delay adjustment
5. Temperature rating -40°C - +50°
6. .5v - 12v DC .01amp
7. Sealed unit
8. Weather proof
9. .002% accuracy
10. Vibration tolerance adjustment
11. To be used in an external application only
12. No moving parts or external reference
13. Non magnetic
14. PC programmable

Something like a digital compass? I'm not that experience in this field

Just off the top of my head perhaps a couple of reed switches actuated by magnets on the wheels - 1 x n/o and 1x n/c. Then use a PICAXE or similar to monitor the opening and closing etc, and programmed so it indicates which operaes first. eg in one direction one will operate first, in the other direction the other will operate first - on second thought the same principal should work OK with any type of sensors operated by the wheels - just a matter of seeing which one preceeds the other

Or then again maybe I am just getting old and raving on

David -

tecjim wrote:

On 17 Oct 2006 03:32:00 -0700, "tecjim" put finger to keyboard and composed:

How about a $5 optomechanical mouse?

- Franc Zabkar