Everything You Need To Know To Find The Best odometer sensors

That doesn't even look remotely ruggedized, I wouldn't trust it to last very long at all.

Check now

I just use the reed switch sensor that came with a Sigma bicycle computer. If I were to rebuild the system from parts I would probably consider a Hall sensor, though I have had no problems at all to date with the reed switch.

@Joy

Can you get us a picture of your bike ? Around the wheels, specially. If I where you, I look at my situation, determine what type of sensor I will need depend on : location on the bike, to decide if dirt will impede the sensor and vibrations. ( things can got loose when in motion ). hall ? maybe - need to fix a magnet, opto - an open opto coupler - need to fix a light source ( leds or laser or light bulb ), or a small wheel direct couple with a encoder, the small wheel is "rolling" at the tire of the bike like a bycle dynamo.

Just an idea.

I would use that rotation encoder for something like a robot leg or arm joint or something. It doesn't look like it's for continuous rotation. I would use hall sensor on the inside of the fork and attach a small rare earth magnet (strong) on the rim of the front wheel. Then wire up an arduino digital input (and possibly 7-segment LEDs as a readout).
Nearly all bike spoke persistence of vision devices use this technique. There is one limitation to this: the Hall sensor I got has a 0.1ms response time. If your bike is running too fast and your magnet is too small, the magnet spends less than 0.1ms in front of the Hall sensor and the sensor fails to detect the magnet. Say the magnet is 0.5" wide on the rim of the wheel at say 10" radius and the bike is running at 65MPH, then we find the angular speed of the bike wheel is around 100rad/s and the 0.5" magnet is only spending around 0.4ms (if I'm right) so that is getting close to the limit of the Hall sensor.

I wouldn't put the magnet on the rim, but rather on the brake disk. In line with the mounting bolts should work fairly well in most cases. Then it has less of an influence on the balancing of the wheel, and you get a longer duty cycle.

with a 3" mount radius on a 19" rim with a wheel circumference of aprox 1.2 meters and a slightly more realistic magnet size of .1" (only slightly smaller than you'll probably actually use) you're looking at a max speed of about 151 kph, or 94 mph before you start hitting the .1ms barrier (if I've done my math right)

With the reed switch I've personally tested up to about 110 mph, and I've read of it bench tested to over 200mph

I use a bike speedo reed switch on my swingarm and a Magnet epoxied to one of the sprocket mounting bolts. I didn't want to use the brake disc for fear of something sliding into the caliper but it would be hard for the magnet to go anywhere bad from where it is now.

I did experiment with a hall effect sensor and i'm sure the one you're getting is fine. I just didn't find it worked any better and running three leads including +v back to it was annoying.

There might be a picture of the pickup and magnet here http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=

@Joy

Here the site for the datasheet ...AH-34 datasheet & application notes - Datasheet Archive Opps, a different type ...

I am trying to find that sensor. Can you supply a picture ? I need to see a part number on that part.

Make you read the datasheet, connect properly, and a magnet attach to the wheel.

I can't find a datasheet for the AH34, although I found one for the AH342, which may be related.

The US looks suitable to me, however it needs to see a north pole to switch one way and then a south pole to switch the other way. So you would need to use 2 magnets on the wheel, opposite ways round, so that in one rotation the sensor sees both a north pole and a south pole.

dc42:
I can't find a datasheet for the AH34, although I found one for the AH342, which may be related.

The US looks suitable to me, however it needs to see a north pole to switch one way and then a south pole to switch the other way. So you would need to use 2 magnets on the wheel, opposite ways round, so that in one rotation the sensor sees both a north pole and a south pole.

I am also thinking that the US is much better...The datasheet of US says that it is high magnetic sensitivity, so I thing that i can keep the magnet little far too from the sensor..
I bought one AH34 which needs a magnet to be at least half a cm close to it..

I can get these sensors too..

Datasheet

Datasheet

http://www.sunrom.com/sensors/current/hall-effect-sensor

Datasheet
http://www.sunrom.com/files/WSH315.pdf

If you use the US then you will need two magnets anyway (one N and one S towards sensor) but still only get one pulse per revolution.

Two magnets on opposite sides of the wheel will help to avoid unbalancing it. One pulse per rev is all you need, you're only measuring km so you don't need the extra resolution that two pulses would give.

dc42:
If you use the US then you will need two magnets anyway (one N and one S towards sensor) but still only get one pulse per revolution.

Two magnets on opposite sides of the wheel will help to avoid unbalancing it. One pulse per rev is all you need, you're only measuring km so you don't need the extra resolution that two pulses would give.

I want to calculate the 1/10 also for the decimal that is the reason i was asking..
I had open a thread about this few days back..
http://arduino.cc/forum/index.php/topic,.0.html

Link to Autolin

I have access to few of these HALL SENSORS

I can get these sensors too..

Datasheet

Datasheet

http://www.sunrom.com/sensors/current/hall-effect-sensor

Datasheet
http://www.sunrom.com/files/WSH315.pdf

Please check if there is anything as good as US, I dont want the latch effect..
By the way , is there any advantage of that latch effect.

Wondering what an odometer reading is and how to read it? This article explains everything you need to know.

Your car’s dashboard contains many gauges and measurements, but the odometer reading might be the most important. This random set of numbers means more than you might be aware of.

Whether you have a mechanical or electronic odometer, you can read the numbers that are shown. These numbers show how many total miles the vehicle has been driven. However, there are some ways these numbers can be messed with, giving you a false impression.

In this guide, we show you how to read the odometer. We also explain what it means to roll back the odometer and how you can avoid becoming a victim of this practice.

HOW DOES THE ODOMETER WORK?

The odometer is a measurement device that shows the total distance travelled by the car. It’s found on the car’s dashboard. Two Greek words come together to form the word “odometer,” leaving us with the meaning of path and measure.

There is also a trip odometer on most cars. Unlike the standard odometer, the trip odometer is easy to reset to show how many miles were travelled during a specific time. It’s a helpful tool if you want to figure out the approximate gas mileage of your vehicle.

HOW TO CHECK THE ODOMETER READING?

1. Mechanical Odometer
   
   

The mechanical odometer is constructed with a few cogs. Each one represents a numerical digit. However, the mechanical odometer operation actually begins at the car’s transmission. The small gear used to change the odometer is found attached to the transmission.

The drive cable for the speedometer is connected to this gear, with the other end reaching the instrument cluster. As the car moves, the transmission gear also turns in conjunction. The drive cable connected to it changes the digits on the odometer.

As can be seen by the illustration above, the counting begins on the right. This particular odometer shows 160,648 km. All of these numbers will reach a peak value before resetting to zero and starting again. However, the mechanical odometer numbers can often be slightly off-centre, making them more difficult to read.

2. Electronic Odometer
   
   

The electronic odometer design is newer than the mechanical type. It’s a digital odometer that is run by the electrical system. While there is still a special gear measuring the mileage, there isn’t a drive cable. Instead, a magnetic sensor is used to count how often the gear turns with the transmission. The mileage is then shown by the numbers reflected on the dashboard electronically.

The electronic odometer is more accurate than a mechanical one and it’s not as easy to alter. If you look at the illustration above, it shows the mileage of the vehicle at km, revealed electronically.

WHY IS THE ODOMETER READING IMPORTANT?

The numbers you read on the odometer show you how many miles the vehicle has travelled. When you look at the odometer, you know how many miles are on that vehicle’s engine, transmission and other vital parts.

This measurement is important to know before you purchase a vehicle since the mileage determines a large part of the car’s value. Vehicles are often priced according to the model year, condition and mileage. The lower the mileage, the higher the resale value typically is.

HOW TO CALCULATE FUEL ECONOMY WITH THE ODOMETER?

You can use the odometer to figure out the approximate fuel economy of your vehicle. Knowing what the car should be getting, you can determine if the engine isn’t working as it should.

1. When your fill-up the gas tank, reset the trip odometer.
2. Drive normally until the next time your fill-up.
3. At that filling session, write down the number of gallons you added and take note of the trip mileage since the last fill-up. This shows how many miles you drove for that many gallons of gas.
4. You can divide the number of miles driven by the number of gallons you put in the tank. For example, if you drove 200 miles on 10 gallons of fuel, the average fuel economy was 20 mpg.

To get the most accurate reading, try to record the mileage for an entire tank of fuel. You can also perform the test several times to see a better average.

CAN THE ODOMETER BE WRONG?

It’s possible for the odometer to show the wrong measurement. If you have a mechanical odometer, you want to watch it periodically to ensure it is recording the mileage correctly. If you measure the distance you’ve driven, the odometer should accurately report it.

If the odometer isn’t working correctly, even a little, the mistake can quickly add up. Let’s assume that the odometer changes too soon, even by a little. It won’t take long before the car is showing far more miles than what has actually been driven, leading it to lose resale value unnecessarily.

It’s possible to have the fault repaired and get back on track. If you plan to sell your car in the future, this is something you want to take care of right away.

For more odometer sensorsinformation, please contact us. We will provide professional answers.