Dynamotion > Mach3 Defining Axes - Page 3


Page 3 of 3 FirstFirst 123
Results 25 to 31 of 31

Thread: Dynamotion > Mach3 Defining Axes

  1. #25
    Registered
    Join Date
    Mar 2010
    Location
    USA
    Posts
    32
    Downloads
    0
    Uploads
    0

    Default Re: Dynamotion > Mach3 Defining Axes

    Actively driven as in current from the 5 volt source to the input when the switch is closed, and pulled low with a resistor when open. J7 inputs have internal resistors.

    Sent from my SM-G900V using Tapatalk



  2. #26
    Gold Member TomKerekes's Avatar
    Join Date
    May 2006
    Location
    USA
    Posts
    2330
    Downloads
    0
    Uploads
    0

    Default Re: Dynamotion > Mach3 Defining Axes

    Hi toolbag33,

    I'm having difficulty understanding.

    I already recommended to not switch 5V directly to any KFLOP inputs. Are you still doing this?

    JP7 does not have any pull down resistors. Have you added some?

    Regards

    TK
    http://dynomotion.com


  3. #27
    Registered
    Join Date
    Mar 2010
    Location
    USA
    Posts
    32
    Downloads
    0
    Uploads
    0

    Default Re: Dynamotion > Mach3 Defining Axes

    Quote Originally Posted by TomKerekes View Post
    Hi toolbag33,

    I'm having difficulty understanding.

    I already recommended to not switch 5V directly to any KFLOP inputs. Are you still doing this?

    JP7 does not have any pull down resistors. Have you added some?

    Regards
    Then how do I drive the inputs high?

    Sent from my SM-G900V using Tapatalk



  4. #28
    Registered
    Join Date
    Mar 2010
    Location
    USA
    Posts
    32
    Downloads
    0
    Uploads
    0

    Default Re: Dynamotion > Mach3 Defining Axes

    Tom Kerekes,
    If you not going to answer my questions in a correct and helpful way, just don't Post anything!

    Sent from my SM-G900V using Tapatalk



  5. #29
    Registered
    Join Date
    Mar 2010
    Location
    USA
    Posts
    32
    Downloads
    0
    Uploads
    0

    Default Re: Dynamotion > Mach3 Defining Axes

    There's got to be a ground in there some where right? So 5v to switch, to input, to ground. Current flow when the switch is closed, driving the input high. 10k ohm between the switch and ground to drive input low when switch is open.

    Sent from my SM-G900V using Tapatalk



  6. #30
    Registered
    Join Date
    Jun 2004
    Location
    Scotland
    Posts
    253
    Downloads
    0
    Uploads
    0

    Default Re: Dynamotion > Mach3 Defining Axes

    ToolBag, what you are proposing would work, however as Tom has already said, it's not ideal to connect the inputs directly to 5V.

    What would be better is if your switches are at 5V, is connect a 10K resistor between the KFlop input pin and 0V, then wire a 5K resistor in series between the switch and input pin. That way when the switch is open, the 10K resistor pulls the input to 0V, but when the switch is closed and the 5V connected via the 5K resistor, the two resistors act as a voltage divider, so the input pin sees 3.3V.

    I've used those values as an example, however I'd probably use lower values, as the 15k at 5V, means only 0.33mA of current flows, which could make things susceptible to noise. I'd personally aim for at least 5mA of current flowing, which means using a total resistance of just 1000ohm. But that would mean using 330ohm and 770ohm resistor, which might not be that common (without looking at a catalogue, I'm not sure if those are common values or not!). The key thing is to aim for the 2:1 ratio between the resistors, so you still get around 3.3V.



  7. #31
    Registered
    Join Date
    Mar 2010
    Location
    USA
    Posts
    32
    Downloads
    0
    Uploads
    0

    Default Re: Dynamotion > Mach3 Defining Axes

    M_C,
    This is just getting better! I ran chose to use j4 which have the pull down resistors when the switch is open, and ran 3.3 volts to one side of of all my limits and the other to the inputs, on j4 and it cooked my board! Godaamnit! Even though the manual said these were 3.3 volt tolerant, when I plug my board in no more lights. Oh well. I'm sure I did something wrong. But how? Did I need a ground on the input side as well?

    Thanks



Page 3 of 3 FirstFirst 123

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

Dynamotion > Mach3 Defining Axes
Dynamotion > Mach3 Defining Axes