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    [Moved] How to read TTL Signal from sensor with Microcontroller ?

    Can any one help me to read TTL signal(5V TTL-Compatible) to read with Microcontroller ?I am having Pressure sensor with output TTL. Sensor having 3 pins One is Vcc ,GND and Signal(5v -TTL Compatible ).

    I am using stm32 Nucleo board . Please suggest me how to read it .

    Thanks,

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    [Moved] Re: How to read TTL Signal from sensor with Microcontroller ?

    Hi,

    To get a good and reliable answer you should:
    * give us the exact type and vendor of the sensor, or (a link to) the datasheet
    * give us the exact type and vendor of the microcontroller, or (a link to) the datasheet
    * the schematic, with addition information like: voltages, part values...

    In detail:
    V_OH of the sensor needs to be compatible with V_IH and V_Imax of the microcontroller.
    (V_low usally is not problematic, but it's a good idea to check it, too)
    Often the voltage levels depend on circuitry and power supply voltage.

    You say "5V TTL compatible"...
    But is it a true push pull TTL output, or just "TTL compatible"?
    A true TTL output drives a HIGH signal higher than 2.0V, whereas a "compatible" output can be a "open collector" whuch needs an external pullup resistor to get valid HIGH levels.

    Klaus
    Please donīt contact me via PM, because there is no time to respond to them. No friend requests. Thank you.



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    Re: [Moved] Re: How to read TTL Signal from sensor with Microcontroller ?

    Thanks for your reply,

    Micro controller link -- https://www.st.com/en/evaluation-too...eo-l073rz.html

    Sensor vendor link -- https://www.digisens.ch/images/S018E_12_KL66.pdf


    Please let me know the inputs to read the data with MCU.



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    Re: [Moved] How to read TTL Signal from sensor with Microcontroller ?

    Quote Originally Posted by KlausST View Post
    Hi,

    The sensor datasheet just says "5V TTL (compatible)" ouput.
    Thus it should be
    LOW: <0.4V
    HIGH: >2.4V
    according TTL standard.
    (You could easily find the values on your own: Just do an internet search for "TTL voltage levels")


    This is not what I was asking for.

    Please show a little effort on your own: Read the microcontroller (not the evaluation board) datasheet and find out V_IH and V_Imax. (as already meantioned in post#2)

    Mind: The signal is no "digtal data" signal. Itīs just a frequeny. --> you need to do a frequency measurement.

    Klaus

    Thanks for your reply ,

    I have tried it on my own only ,but everywhere i am seeing what is a TTL signal couldn't find how to interface read them with any MCU .
    If you could explain me that would be really appreciated .

    Can i able to read this signal using ADC of micro controller before that many docs i found that TTL is nothing but a native serial .I don't have clarification on it .

    Kindly help to solve this .

    Thanks,



  5. #5
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    Re: [Moved] How to read TTL Signal from sensor with Microcontroller ?

    [Sorry for the confused order of posts]

    Hi,

    The sensor datasheet just says "5V TTL (compatible)" ouput.
    Thus it should be
    LOW: <0.4V
    HIGH: >2.4V
    according TTL standard.
    (You could easily find the values on your own: Just do an internet search for "TTL voltage levels")

    This is not what I was asking for.

    Please show a little effort on your own: Read the microcontroller (not the evaluation board) datasheet and find out V_IH and V_Imax. (as already meantioned in post#2)

    Mind: The signal is no "digtal data" signal. Itīs just a frequeny. --> you need to do a frequency measurement.

    Klaus

    - - - Updated - - -

    Hi,

    I have tried it on my own only ,but everywhere i am seeing what is a TTL signal couldn't find how to interface read them with any MCU .
    If you could explain me that would be really appreciated .
    I wonīt look for the datasheet, download it and search the document for "V_IH"...
    It is your job, and if you want others do your job you should consider to pay for this.
    But even for this you need to give the requested information: exact type of microcontroller.

    It is a simple task you need to be able to do this on your own.
    With almost every datasheet there is a section "electrical characteristics" ... there it should be easy to find "V_IH".

    Klaus
    Please donīt contact me via PM, because there is no time to respond to them. No friend requests. Thank you.



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