# Wheel Speed Sensor



## Little Rhody (Jun 17, 2008)

Here is a nice little tool made just for EV builds. 
http://www.electricmotorsport.com/store/ems_ev_parts_drainbrain-cycle-analyst.php

Another option is to buy an after market cruse control unit from an automotive parts store, and use the part from it to get the signal. 

LR


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## kogan (May 27, 2008)

Here's another different idea. Get a $20 radar gun, mount it under the car and point it at the ground. http://cgi.ebay.com/HOTWHEELS-RADAR...ryZ45352QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

And of course extend the wires for the LED display and mount it on your dash. I've got no idea if this would work since I've never driven around with a radar gun


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## Nodd (Jun 6, 2008)

I'm using a bicycle speedometer on my EV. Its magnetic speed sensor is attached to one of the axles. Most Cyclocomputers have odometers & other features built in.

Google "cyclocomputer" or there's a pretty good selection available at this website: http://www.qbike.com/listing/Cyclocomputer/


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## namyzarc (Mar 18, 2008)

Install a GPS! Not only will u have GPS functionality, but most will display your speed & they are often way more accurate than the cars original speedometer!


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## iss407 (Dec 6, 2007)

A Cyclometer is a great idea! Eventually I want all kinds of stats and stuff, but right now I just want to get something out of the garage that I can use.


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## iss407 (Dec 6, 2007)

A GPS receiver with a USB to connect to my laptop would be even better. With a way to get battery voltage and current inputs I could code something very useful. Hmmmmmm


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## namyzarc (Mar 18, 2008)

iss407 said:


> A GPS receiver with a USB to connect to my laptop would be even better. With a way to get battery voltage and current inputs I could code something very useful. Hmmmmmm


Actually you wouldn't need a GPS reciever with a USB to connect to your laptop. Just get Microsoft Streets & trips softwarre (I think) wich comes with it's own USB GPS device for about $50 on eBay. I've used it for my ICE car & it works great!

Edit: Spelling/price


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## maiku (Jun 1, 2008)

just a question, but what's to stop you from still using the ECU to control the sensor?
i mean, either than that, the ECU wouldn't be doing much else
you can just remove the error lights from the dash

seems a bit less complicated to keep your speedo working


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## Manntis (May 22, 2008)

iss407 said:


> A GPS receiver with a USB to connect to my laptop would be even better. With a way to get battery voltage and current inputs I could code something very useful. Hmmmmmm


I use a dedicated carputer and have been trying to think of ways to modify the GUI to include battery strength, OBD, etc. alongside the media, GPS Nav, and Bluetooth Cellphone features


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## kittydog42 (Sep 18, 2007)

Two points:

1. They do make a GPS speedometer for automotive use that looks like a normal speedometer. I am a reseller of these.

http://www.nordskogperformance.net/products/marine/gps/detail/hga090.htm

2. The speedometer should still work without the ECU.


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## iss407 (Dec 6, 2007)

I might be able to use the ECU, I'll look into it. Good idea.

As for GPS I think I'm gonna get the Asus R130. Only $150, full navigation, media player, Bluetooth speakerphone. I didn't realize those things had gotten so good.

-- Paul


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## Madmac (Mar 14, 2008)

"I use a dedicated carputer and have been trying to think of ways to modify the GUI to include battery strength, OBD, etc. alongside the media, GPS Nav, and Bluetooth Cellphone features "

I have been using Roadrunner front end on a car PC. This can be skinned to produce an interface as required. I have modified JohnWPB's (many thanks for the hard work and making available to all) DigitalFx3. You can look at it here.

http://www.mp3car.com/vbulletin/rr-skins/117143-digitalfx-3-0-released.html

Road runner allows easy creation of plugins and shell code is available in VB and C.

This is the first go at displaying info from prototype battery pack.


Madmac


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## Gravitic Anomaly (Jun 19, 2008)

Typically GM uses a 4000 pulse per mile signal for the speedo and odometer operation. A hall effect magnetic pickup is used to read a toothed wheel in the transmision. If you have a manual tranny on the car you can still run the ECU as is. If you don't have a transmission you can re-use the sensor and provide your own target wheel with enough teeth to give you the 4000 ppm signal through the ECU.
You can also completely bypass the cars digital electronics. Go to a junk yard and pull the speedomoter circuit card out of the instrument cluster of a mid '90's GM car like a cavalier. Disconnect the speedometer movement from the Instrument cluster circuit board and plug it into the cavalier card. There will be one of four possible connections to the speedo that works. Run 12v and ground to the card and your set to read a 4000 ppm signal. The actual dual coil meter movement in the cars hasn't changed in 30 years.
I upgraded a Fiero to a modern ECU with serial communications and this method worked flawlessly for both the tach and speedo/odo.

- GA


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