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BLTouch installation

Discussion in 'Mods and Upgrades' started by Storm, Aug 25, 2021.

  1. Storm

    Storm New Member

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    Hello,
    first of all, i hope this question has not been asked before.

    I want to install a BLTouch sensor for my printer. My problem is, that i can't identify the proper pins to connect it to. I have connected all cables and the sensor is getting recognized, i can't reach it with any M-commands though.

    Since there is no documentation on the location of the pin numbers, i can't connect the cables to the pins specified in the arduino code.

    Has anyone of you installed a similiar sensor yet? Which pins did you connect it to and which number did you specify in the firmware?

    Thank you for your help!

    Storm
     
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    The R2 already has a Z sensor (a UV one) so I would imagine the connection for the BLTouch might be similar ... their source code should tell you which pins they are expecting that to be tied to. (https://github.com/Robo3D) I am not sure how much luck you would have wiring up such a sensor to the stock robo controller board since it is not well documented and they did not have any unused pins floating around on it (or not many). You could consider doing what a few others have done and replace the custom board with an Arduino/RAMPS combo and then hook it up to whatever pins you need (and customize the Marlin firmware).

    @Lance Weston designed a board/setup to make this easier and PartsBuilt.com carries it -- Lance can provide you more details if you want to know more about that approach.
     
  3. Lance Weston

    Lance Weston Active Member

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    The existing IR board has 3 connections: +5v, GND, signal. The signal returns to GND when the sensor is close to the plate. The pin numbers are the same on the Partsbuilt.com board. I can show you where in the Marlin code the pin numbers are and how to change the sense from positive to negative if required.

    Okay, I looked up the BLtouch and discovered that you need an output from the board to raise the pin. You will require a Partsbuilt.com system board which has servo output pins. Once you have installed the Partsbuilt board you will have to purchase a dupont connector kit and a crimp tool. You can then use the code supplied by BL touch to make use of the servo pin you select with the dupont connector..

    I was not impressed with the BLtouch specs and see no improvement over the IR board.
     
    #3 Lance Weston, Aug 25, 2021
    Last edited: Aug 25, 2021
  4. Storm

    Storm New Member

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    I have the C2 Mainboard available on Partsbuild.com installed. I know where to find the Pins in Marlin and how to change them, i just dont know which Pin on the board corresponds to which Pin number in Marlin.
    The sonsor is connected via dupont connectors.

    The board has no specified servo Pins so i tried to manually configure the SERVO0_PIN in Marlin and connect the dupont connector to it on the board, but it did not work.
     
  5. Lance Weston

    Lance Weston Active Member

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  6. Lance Weston

    Lance Weston Active Member

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    I do not know how you got to the servo0. Here are the pins on the headers.



    upload_2021-8-26_8-54-22.png
     
    #6 Lance Weston, Aug 26, 2021
    Last edited: Aug 26, 2021
  7. Lance Weston

    Lance Weston Active Member

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    upload_2021-8-26_9-25-24.png
     
  8. Lance Weston

    Lance Weston Active Member

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  9. Lance Weston

    Lance Weston Active Member

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    So LCD4 D4 is (D23), PA1 AD1, which is PIN23 in Marlin and is not used on the Robo board. You should be able to use it for your servo0.
     
  10. Lance Weston

    Lance Weston Active Member

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    This shows the servos pin numbers so you know which pin number to swap
    upload_2021-8-26_15-39-17.png
     
  11. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    No, your best bet is to convert the board to an Arduino Mega/RAMPS and @Lance Weston can get you the details on that combo and an adapter that PartsBuilt had built for him.

    I looked and did not see it on their site, but he should be able to point you to how you can order it or reach out to partsbuilt and ask them

    That way you are on a known, documented board.
     
  12. Lance Weston

    Lance Weston Active Member

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    The Partsbuilt board had the z height inputs under a connector so they can only be gotten to on the print head. This would require a custom connector.. It should not really be a problem to reassign the servo output to D23 on the Robo system board header. The Partsbuilt board is available here. https://www.partsbuilt.com/mainboard-replacement-r2-zboard/

    The partsbuilt board is layed out to accept the C2 power connector and you should be able to have them put that connector in instead of the R2. That is the only difference between the R2 and C2 boards.
     
    #12 Lance Weston, Aug 26, 2021
    Last edited: Aug 26, 2021
    mark tomlinson likes this.
  13. Storm

    Storm New Member

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    Thank you for all your help!

    If i were to use the IR sensor how would I update the firmware to use it?
    I can find the firmware for the sensor on GitHub, do i just flash this new firmware or how would i do that?

    The Sensor will be conected to the board above to nozzle (uptown board?) right?

    Sorry if i am asking stupid questions or if there is already a guide somewhere on this. I am a student trying to understand.

    Thanks,
    Storm
     
  14. Lance Weston

    Lance Weston Active Member

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    You should have and existing sensor mounted to the back of your shroud and a three wire cable that runs from the cutout in the aluminum plate to it. If the sensor and cable are not there you can purchase at partsbuilt.com. You do not have to update the firmware to use the sensor, it is built in.

    I do not find sensors work on any surface but the Robo surface. I use micro porous glass which has a deposited pattern on it, which the sensors can not accurately use. I need .01 mm and sensors seem only good to .05 mm.

    goto settings->gcode scripts and see if G36 is commented out. If not uncomment it and set up the auto level on the LCD
     
    #14 Lance Weston, Aug 27, 2021
    Last edited: Aug 27, 2021
  15. Storm

    Storm New Member

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    Thanks for the info. I got the IR Sensor and have it running smoothly.
    But i know have another big problem i am running into. After running G36 and thus setting my Z0 perfectly on my build platform, when i want to start printing, the nozzle will print about 10mm above the actual buildplate. G0 Z0 moves it back to the plate, where it should be. Do you know, what the reason for that may be?

    Storm
     
  16. Lance Weston

    Lance Weston Active Member

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    After you do a zoffset on the LCD you have to do a fine tune. That will allow you to set the offset for the IR sensor.
     

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