Digital Speedometer

[srspinho]

Hi Guys,

do someone have a project of a digital speedometer for cars ?

Thanks !

Sérgio

[fmssp]

http://www.siliconchip.com.au/cms/A_103208/article.html
http://www.siliconchip.com.au/cms/A_103355/article.html

http://www.edn.com/article/CA529384.html

Success!

Sergey 

[darksky]

What about using GPS - this is the best way.

[srspinho]

Thank you Guys !

[frasenci]

Hi there ,

From the 3 excellent links we got from fmssp , I liked the 3rd most because of its simplicity srspinho.

But you can make it simpler on replacing the Hall-Effect sensor with an Optical one .
In my experience , once you are done with the Hardware-Software part , comes the trouble to attach those magnets on to the rotating part you want to sense,.....

I succesfully use QRD1114 as a sensor , only thing needed to sense the movement is a tiny White-Black transitions spot on rotational part,... ( Can also use OPTEK 703 ). I commonly use Girls Nail Paint for this painting ( clean part before apply).


I have some real world applications of this using Basic PIC processor and very simple PULSE IN code to get an speedometer for a few $.

Moreover , QRD1114 can easily be used as a proximity sensor , or distance measure in the 0 - 100 mm range. A nice IC I must say and cheap.

If still interested , maybe I can help you set up one of these,

Greetings
FAA

 

[srspinho]

Hi friend,

first of all, excuse-me for my Biiig delay answering your Post.

I was on vacation and far away from computers ! 

Well, I´m doing my speedometer using PicBasic Pro.

The Timer 0 counts a 250 ms period and Timer 1 works as a pulse counter.

I know that my Opel Corsa has a Speed Sensor (VSS) which could be used to give me the right number of pulses for each car´s wheel revolutin (i guess it is 8 pulses / revolution in a 14 inch wheel)


I´m trying to do a Schmitt Trigger with a Ne555 to capture de pulses from a sensor

The problem is that here in Brazil No one wants to give the right information about the sensor. Everybody wants to sell the information in book for about US$ 80,00 ! ! ! ! ! !

have you ever did something with car´s Speed sensor ?  Is the output of this kind of sensor in low voltage enough to work with the 555 ?

If you have any information about the speedometer´s implementation... Anything.... Iwould be happy !


thank you !

Sérgio

[fmssp]

Hi friend,
If you have any information about the speedometer´s implementation... Anything.... Iwould be happy !
thank you !

Sérgio

Hi Sergio!
The speed sensor has on output NPN OC. With the uC it is enough For the interface here such scheme. At the European cars - 1000 turns of a speed sensor = 1 kilometer of road. At American = 1 mile. The quantity of impulses on one turn of the gauge can be 6, 8 or 10.

Success!

Sergey.

[nileshhande]

Hi friend,
If you have any information about the speedometer´s implementation... Anything.... Iwould be happy !
thank you !

Sérgio

Hi Sergio!
The speed sensor has on output NPN OC. With the uC it is enough For the interface here such scheme. At the European cars - 1000 turns of a speed sensor = 1 kilometer of road. At American = 1 mile. The quantity of impulses on one turn of the gauge can be 6, 8 or 10.

Success!

Sergey.

HI,
please share the source code..

Thanks..

[fmssp]

HI,
please share the source code..

Thanks..

http://analarc.narod.ru/hobby/panel/speedmtr/spedometr.html

Digital speedmeter on 16f84. The scheme and an source code.
In Russian!

[fmssp]

Here still the interesting schematic of the multiple-purpose interface for different types of speed sensors.  The choice of type of the gauge is made by the software: pull up or pull down resistance or AC.

http://203.57.155.69/cms/A_108157/article.html

[srspinho]

Hi Friends !

many many thanks for your Reply !

Recently, I discovered that my Opel Corsa (or Vauxhall Barina) has a "Distance sensor" which gives some pulses to Corsas´s digital mileage counter.

Whell, a Friend told me that this sensor works like that :

(This data are for a 13 Inch wheel )

1) The sensor is conected to ther gear Box
2) For : 10 Km/h -> 45 Hz
    For : 20 Km/h -> 90 Hz
    For : 40 Km/h -> 180 Hz   and so on...

in this case, velocity is :  V = 0.2222 * F 

If using uC : V = (10 * V) / 45

well...

Is late night here in Brazil, so, I will have to check my Tire´s rolling radius in order to calculate the quivalence for me, because my Corsa has 14 Inch wheels.

When i get the calculations ready, I will post it here !

Thanks every body


regards

Sérgio

[milan]

Fiat tipo have digital board and digital speedometer. You can find shematics searching google.