Connecting a Wheel speed sensor ?

Forum 2005-2010 (read only) Hardware Interfacing
1

Hello, i've got a problem with the wheel speed sensor

This wheel speed sensor is from the ABS (anti brake-locked system). I've been thinking that if i connect this sensor to the microcontroller(Arduino Duemilanove ATmega168), do i need any components to convert the signal to the MCU? This wheel speed will be shown on LCD.

The sensor output signal is analog, it will generate alternating current. The freguency and amplitude of this alternating current are proportional to wheel speed.

If i just connect the speed sensor to the MCU wrong, does the MCU will be damaged ?

2

Hi,

the information is not sufficient. Waht is the maximum Amplitude of the signal? if it is higher than the supply voltage of the chip (5V) or below 0 Volt it can damage the arduino.

Mike

3

Thanks Mike,

If the problem you said is ignored, which mean the maximum amplitude of the sensor doesn't exceed the voltage limit of the microcontroller.

The sensor generates alternating current which is analog singal, this analog will be coverted to digital by Analog to Digital Converter (ADC). After the conversion, could i use th digital signal to calculate the velocity of the motor ?

4

Hi,

yes you can use the digital signal form the ADC for your calculation if the voltage level of the ADC is TTL (otherwise you need a level shifter) and if you know how to interpret the value from the ADC. How do you get access to the ADC value? Does the ADC output its value parallel or has the ADC some kind of bus?

Mike

5

Hi,

Sorry, what is TTL ? and i don't understand that how to interpret the value from ADC. I just have the basic concept in microcontroller :frowning:

If i want to convert the analog to digital, it's not just connect the sensor to the analog input, and program it ? If not, how to do the coversion ?

Thanks

6

Hi,

TTL is Transistor Transistor Logik, which normally works with 5V. But this was a misunderstanding. If you try to connect the analog output to the analog Input of the arduino - this is ok. You mentioned that the amplitude as well as the frequency of the sensor signal are proportional to the wheel speed. If this is true, the easiest way is to connect the sensor signal to the analog input of the arduino in the following way:

This circuit will make a DC - voltage proportional to the amplitude of the sensor. The values of the resistor and the capacitator depends on the frequency of the signal.

Mike

7

Oh my god
It helps a lot
I am going to make this thing
I will post the product when i have made that kind of thing :slight_smile:

Thanks Mike :wink:

8

Ah!
one more thing, if the sensor is connected like you said, for the calculation, could i program it to use the Timer for calculation in the MCU ? or there is another method for calculation?

Thanks :slight_smile:

9

one more thing, if the sensor is connected like you said, for the calculation, could i program it to use the Timer for calculation in the MCU ? or there is another method for calculation?

Hi everyone,

Anyone know what i am saying ? :slight_smile:

Thanks a lot