Vanilla Marlin Firmware configured for Ender 3 + BLTouch

This is the 1.1.9 version of vanilla Marlin Firmware pre-configured for Creality Ender 3 printers with the original or generic BL Touch sensors. The standard configuration file from Marlin distribution was carefully reviewed to include the latest Ender 3 specific settings from the official Creality firmware. If you don't have a BLTouch sensor please use this version of Marlin that supports Mesh Bed Leveling.

I made avaliable the 2.x versions of Marlin for the same board and printer but I recommend using the 1.1.9.x because it is much more stable and has more features. The 2.x versions of Marlin are too big for the board memory and several features had to be removed in order to fit the firmware.

There are three installation options available, the traditional with Arduino IDE, the new method using Visual Studio Code + PlatformIO and the third one that is uploading the compiled firmware directly to the board. I recommend the PlatformIO option for most of the users, once the software is downloaded, the firmware can be upgraded in less than 5 minutes.

This firmware was made for 8-bit boards and will not work on 32-bit boards.


  • Official Marlin firmware + bugfix with all hardware settings from Creality latest official firmware (April 2020).
  • BLTouch original/generic up to 3.x. enabled by default (BLTouch 3.x might need the 5V logic enabled from the LCD menu).
  • No need to remove any capacitors from the board.
  • Installs from the original Arduino IDE (smaller download and frequent updates from Arduino team).
  • Source code was modified to prevent releasing the BLTouch sensor during "beep" events triggered by LCD menus.
  • Thermal runway protection enabled.
  • Does not reset the bed level settings after the G28 (Home) command.
  • Custom menu with maintenance mode, emergency mode and full auto bed leveling sequence (warmup, wait, home, level and then save settings).
  • Ultra-precise bilinerar bed leveling algorithm with 25 probing points and slow probing (takes around 5 minutes to complete, 10 including the bed heating).
  • Run and toggle the bed level and BLTouch tools from LCD menus.
  • BLTouch voltage/logic settings from the LCD menu.
  • Slim menus enabled.
  • Baby steps enabled and configured for the "Magic Numbers".
  • Emergency parser enabled.
  • All changes from the original Marlin config file were marked with the comment  "//Customized DBP"


  • 8-bit boards only! This will not work with 32-bit boards.
  • BLTouch installed on pin 27
  • Z stop switch removed (it can block the Z axis movement)
  • IMPORTANT! BLTouch tip height must be adjusted according to the official instruction manuals. There are different BLTouch sensors and the YouTube videos tips are most of the times wrong
  • Bootloader installed in your board
  • Arduino IDE for installation option 1
  • Visual Studio Code for installation option 2
  • AVRDude for installation option 3 in Linux or MacOS (AVRDude for Windows is included in the package)

Note about the bed leveling strategy

There are two ways to perform the automatic bed leveling, the first is before every print and the second is only when necessary. Based on my experience with the Ender 3, it's better to do an extremely precise (slower) bed leveling when necessary than a simpler one before every print. This firmware configuration reflects this choice.

If you want to do quick/imprecise bed leveling before every print you will need to reconfigure the firmware.

Instructions using Arduino IDE (option 1)

  1. Install the Arduino IDE
  2. Quit any software that could try to access the printer from the USB port (Cura, Serial Monitor, OctoPrint, etc...).
  3. Run the Arduino IDE and configure to download the Sanguino board. Add the following URL to the board manager (File->Preferences->Additional boards manager):


  4. Install the following libraries/boards in the Arduino IDE:
    • U8Glib
    • Sanguino
  5. With all requirements in place unpack this entire Marlin distribution to a folder and open the "Marlin.ino" file from the Arduino IDE.
  6. Look for the configuration.h file and change the following lines to the relative coordinates of your BLTouch mount to the Nozzle. The actual settings are for this mount. If you don't have the measurements now you can configure it later with the M851 GCode (see instructions below).

  7. Disable the endstop interrupts feature by commenting (//) the following line in configuration.h. This feature needs to be disabled only if you are using Arduino IDE, with PlatformIO this problem does not exist.



  8. Compile and upload the firmware. Make sure you are using the following settings.
    • Board configuration: ATMega 1284P 16Mhz
    • Programmer configuration: AVRISP MKII
    • COM Port: Depends of your computer. Usually only one is available for selection.
  9. Follow the post-installation instructions below.

Instructions using Visual Studio Code + PlatformIO (option 2)

  1. Download and install Visual Studio Code.
  2. From Visual Studio Code extension menu, install the PlatformIO IDE extension.
  3. With all requirements running, unpack the entire Marlin source code downloaded from the link below to a folder.
  4. From Visual Studio Code select File->Open folder and select the folder where the platformio.ini file is located. Attention! Use the "open folder" command, not the"open file".
  5. Look for the configuration.h inside the "Marlin" sub-folder and edit the following configuration to the relative coordinates of your BLTouch mount to the Nozzle. This does not need to be too precise, the only purpose is avoiding the probe to test outside the bed. The default settings X = -42mm, Y= -5mm and Z=0 are for this mount:
  6. Save the file and then select Terminal->Run Task->Build . It will take a few minutes for the system to download all dependencies and compile the code.
  7. If the code compiled properly you will see something like this in the terminal: "=== 1 succeeded in 00:00:30.050 ===".
  8. Connect your printer to the computer using the USB cable.
  9. Go to the Visual Code menu Terminal->Run Task->Upload .
  10. If everything goes well another message like this "=== 1 succeeded in 00:00:55.010 ===" will be printed.

Installing the pre-compiled HEX (option 3)

The pre-compiled firmware is also available here. You can simply burn the compiled HEX file directly to your Ender3 board without installing the Arduino IDE or Visual Studio Code.

To upload the pre-compiled firmware you will need the AVRDUDE 6.3 tool. For your convenience I included the Windows version of this tool in the zip file that contains the HEX firmware but the tool is also shipped with the Arduino IDE. The upload command in Windows PowerShell should look like this:

./avrdude -p atmega1284p -c arduino -P COM3 -b 115200 -v -U flash:w:firmware.hex:i

The serial port is something between COM1 and COM8, depending on where the USB driver is pointing to, and firmware.hex is the file you are uploading. If you are using other operating system like Linux the port address will be somehting like this /dev/ttyUSB0.

After initializing the board with the new firmware don't forget to reconfigure the probe offsets running the following command from any serial terminal. Replace the default offset values in the command (-42, -5, 0) with the ones for your probe mount.

M851 X-42 Y-5 Z0

Finally, follow the post-installation instructions below.

Post-installation configuration

  1. Manually pre-level the bed! This is important because the BLTouch has limited max/min detection ranges and the print quality can be affected if the Z-Axis moves too much.
    1. Cool down the bed and the nozzle. Heating should have little to no effect on this specific procedure.
    2. Disable stepper motors using the LCD menu command.
    3. Place a credit card on one the bed, the thickness of the card will be used as a reference distance.
    4. Turn the Z axis with your hand until the nozzle hits the credit card.
    5. Move hot end to several positions of the bed, starting from the 4 corners. For each position, adjust the bed level knobs to keep the nozzle at the credit card thickness distance from the nozzle. This is what you would do in manual calibration but instead of using a paper you will use the card for convenience. The card thickness does not matter because the BLTouch probe will redefine the Z reference.
  2. Heat the bed to the printing temperature and run the bed level command from the LCD (Prepare -> Bed Leveling -> Level bed)  or using the G29 gcode or using the Heat and Level command from the custom menu (recommended). Note that the Heat and Level command waits 2 minutes after the bed is hot to allow the mounted surfaces to expand/contract properly.
  3. Save the settings using the LCD menu or the M500 gcode (if you used the Heat and Level custom command, they will be automatically saved).
  4. Add the following gcode to the startup code of you slicer, right after the line of the G28 command to load the bed level configuration from the memory before every print:
    M420 S1

  5. After enabling the bed level, print something large and flat to adjust the Z offset. The nozzle will always be far from the bed until you adjust the offset to a negative value (LCD -> Prepare -> Bed Leveling -> Z Offset). Don't forget to save the settings after the print to keep the offset in the memory, you can use the LCD or the M500 GCode for this.

Troubleshooting tips

  • No serial COM port appears when connecting to the board: Download the FTDI Drivers
  • Bed level failing:
    • 1st - make sure you manually leveled the bed, the probing tends to fail if any part of the bed is >2mm lower or higher than the home level.
    • 2nd - make sure you have the M420 S1 command AFTER the G28 line in your print initialization GCode.
    • 3rd - make sure your probe was installed properly, there are maximum and minimum height clearences between the BLTouch tip and the nozzle tip and that changes for each version of BLTouch.
    • 4th - check the wiring! Sometimes the wires are inverted in the default connector setup.
    • 5th - if you are using BLTouch 3.x see the next topic.
  • BLTouch 3.x failing to probe: Be aware that this is rare contition, the vast majority of the users run BLTouch 3.x without problems. I suspect this is related with the hardware (probe/board components, etc) and there is little we can do from the firmware side:
    • 1st - Enable the 5V logic in the LCD menu (LCD -> Control-> BLTouch). BLTouch versions 1.x and 2.x don't have voltage modulation do not require this setting.
    • 2nd - If the previous does not work, enable SW mode (LCD -> Control-> BLTouch).
    • 3rd - Enable and adjust the delay setting in configuration_adv.h (requires recompiling the source). This is trial an error but try values from 300 to 700 increasing/decreasing by 100.
    • 4th - If the BLTouch is version 3.0 (not 3.1, 3.x...) enable BLTOUCH_FORCE_MODE_SET setting in the configuration_adv.h.
    • 5th - If none of the above work you either have a faulty probe or a problem with the capacitor in the board.
#define BLTOUCH_DELAY 500
  • Error "..._PIN is not interrupt-capable..." in Arduino IDE: This is an Arduino IDE bug, disable the feature in the configuration.h file according to the example below to fix (put "//"). If you are using PlaformIO you should leave this option enabled.
  • Disable serial port clients before flashing: If the COM ports are used by any other app, the flashing process will fail. Shutdown Cura, OctoPrint, any other slicer and any other Serial Monitor program like the Arduino IDE before compiling/flahsing the new ROM.
  • Correct fuse settings: If you are using other software than AVRDUDE (PROGISP, for example) to upload the firmware make sure you are using the correct fuse settings. Apparently the Creality tutorial has the wrong settings and the board fails to boot afterwards.
  • Reset the EEPROM: Sometimes the EEPROM memory is not reset during the Marlin reflash and this can cause problems. To reset manually use the following G-Codes from any Serial Terminal: M502 followed by M500.
  • Blank screen after flashing: You did not flashed the firmware properly. Please use AVRDude according to the instructions above and if this does not work you might have to reflash the bootloader.
  • Serial Port Monitor for Windows: This small program allows you to send/receive GCode to the printer. If the characters look strange you are probably using the wrong baud rate (start with 115200bps).
  • avrdude: stk500_getsync() attempt 1 of 10: not in sync: Wrong baud rate for the serial port or serial port already in use (OctoPrint, Cura, etc..). Try configuring the upload rate to 115200bps. If you are using PlatformIO to upload, make sure you are using the correct baud rate for your environment in the platformio.ini file.
  • Reconfigure the BLTouch probe offsets: Use the following command replacing the -42, -5 and 0mm coordinates with the offsets of your actual mount:
    M851 X-42 Y-5 Z0

If you have problems compiling the firmware...

I can compile the firmware for you. Please see here for more details.

Other Marlin downloads for Ender 3

Version Bugfix + BLTouch for Ender 3 (Aug 3rd, 2020)
Arduino IDE or PlatformIO
File size
4.2 MB
File 1 SHA256: 1DCD5D998C999C80D72A4153BDF27D3A2682FA5F6E869029EEB282FEE2842739
File 2 SHA256: C69961C0E223D1189FFBC2258DD30D49557BE986C5505011ABBFD479CCE61169
File 3 SHA256: D3CEFC5D5EB7C6536EFDBCED861201DA5E59272FFB0193549E2B469740452F44

Post Categories


I recompiled the version, flashed to my printer and executed 5 times the Heat and Level command. No problems so far. I updated the exact same firmware to the website a few minutes ago.

When alternating between Marlin versions always reset the EEPROM after flashing: M502 followed by M500.

That's interesting. Are you running a BLTouch V3.1? Apart from that thats the only thing I can think of. The rest of the printer is stock.

I'm just got your 2.0.1 Hex file loaded and am testing it to see if it works OK. Its also 22:55 here so I'll leave this to run and try again in the morning.

I have to sday since trying to get the BLTouch installed, it is a complete nightmare :(



The only thing I can see thats different is the BLTouch V3.1 vs V3.0.

I know that the 1.1.9 Marlin releases say they work, but I'm not sure it's true based on this. It could also be that I'm doing something fundamentally wrong and have not understood anything. This is possibly the most likely answer.

I'll download the source to your V1.1.9.1 release, compile and I'll set a video up to track what's going on. Before that I'll try to calibrate the Z probe offset for the 2.0.1 release. I'd like to get that working this morning and then I'll go back to the release and track that carefully. I'm a lot more comfortable digging into the code than digging into the Ender 3 Pro :)

Thanks for your hard work. I'll get there :)


I've gone back to the source code for V1.1.9.1 and downloaded it.

Opened and made three changes to

#define X_PROBE_OFFSET_FROM_EXTRUDER -44  // X offset: -left  +right  [of the nozzle] Customized DBP
#define Y_PROBE_OFFSET_FROM_EXTRUDER -8  // Y offset: -front +behind [the nozzle] Customized DBP
#define Z_PROBE_OFFSET_FROM_EXTRUDER 0   // Z offset: -below +above  [the nozzle] Customized DBP

for the BLtouch bracket.

Compiled it and loaded it on the printer.

Octoprint is removed from system.

I then did:

1. I manually prelevelled the bed using your credit card instructions.

2. I then did an Autohome

2. Set the bed temperature to 60C as that's  my normal working temperature.

3. Waited until it hit 60C

4. Then went to Prepare -> Bed Leveling -> Level bed.

5. The first row across went correctly (AFAIK).

6. The second layer then just gets higher and higher until its almost at the rop of the Z axis frame.

I did try to create a video and accidently pressed the record button twice so it didn;t record.

Went back again to re-record the video and it now works. The bed levelling has gone across without constantly going up. This is very confusing.

So lets try a third attempt with video, which has now also not worked. my iPhone stops recording after 90 secs <grrrr>

This time it's failed again. It did the first rows and then the second row just keeps tracking up the Z axix and never getting lower. It's almost as if the Z value is negated after the first row of checking.

I'm going to look at the code but this makes no sense to me at all. It has worked once and failed twice.


Tried three more times and odd results. The Z Axis movement appears to be inverted after a certain number of rows, but not all the time.

I have issed the M commands to reset the code as well that were advised.

Interestingly I've just tried to do bed levelling from Octoprint and it has the same results, the Z Axis heads upwards not downwards.

Am going to give the "Ultimate Marlin 2 + BLTouch for Ender 3 with OctoPrint" a try. Otherwise the BLtouch V3.1 is coming off and is being sold :(

Hi. I think I found the problem. Apparently there is a bug in the version related with the Z fade height and Automatic Bed Leveling.

There is a patch for this. I will fix the code and post an updated release within a few hours.

The workaround is set the Z fade height to zero during the bed leveling.


Hope all is well with whatever country you're locked down in. Portugal?

Thanks, we were both probably searching the same github repository for the problem. You found it before me.

I have downloaded the source to " Ultimate with Octoprint" and got it to complile. I needed to take out some S-Curve stuff, add in #define EEPROM_AUTO_INIT to get rid of the EPROM error and get it all to fit, and have just downloaded it...

... sounds of printer running doing level bed testing ...

... first row looks OK though BLtouch seems to be doing three probes per point and not two ...

.. second row OK ...

... third row OK ...

... all rows OK ...

Now I'll tryu and print something to calibrate it.

However if you let me know when the new version of 1.1.9.(2?) is ready, I'll download it and kick the tyres. My temptation is to have a minimal version of the firmware and use the Octoprint as the 'brains' of the printer. Not sure how to do it but...



Updated the firmware for This is the latest version and includes the patch for the Z fade conflict. I tested it only once but the calibration went fine without any issues.

As a bonus I also enabled the endstop interrupt feature to save several computing cycles.

I'm getting a compile error with the code1.1.9+Bug release

/Applications/ -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -MMD -flto -mmcu=atmega1284p -DF_CPU=16000000L -DARDUINO=10812 -DARDUINO_AVR_SANGUINO -DARDUINO_ARCH_AVR -I/Applications/ -I/Users/rwillett/Library/Arduino15/packages/Sanguino/hardware/avr/1.0.3/variants/sanguino -I/Users/rwillett/Documents/Arduino/libraries/U8glib/src /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/power_loss_recovery.cpp -o /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/power_loss_recovery.cpp.o
In file included from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/endstops.cpp:35:0:
/var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/endstop_interrupts.h: In function 'void setup_endstop_interrupts()':
endstop_interrupts.h:121:7: error: non-constant condition for static assertion
       static_assert(digitalPinToPCICR(X_MIN_PIN) != NULL, "X_MIN_PIN is not interrupt-capable");
/Applications/ -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -MMD -flto -mmcu=atmega1284p -DF_CPU=16000000L -DARDUINO=10812 -DARDUINO_AVR_SANGUINO -DARDUINO_ARCH_AVR -I/Applications/ -I/Users/rwillett/Library/Arduino15/packages/Sanguino/hardware/avr/1.0.3/variants/sanguino -I/Users/rwillett/Documents/Arduino/libraries/U8glib/src /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/servo.cpp -o /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/servo.cpp.o
In file included from /Applications/,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/HAL.h:36,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/MarlinConfig.h:39,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/Marlin.h:35,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/endstops.cpp:27:
/Users/rwillett/Library/Arduino15/packages/Sanguino/hardware/avr/1.0.3/variants/sanguino/pins_arduino.h:112:70: error: reinterpret_cast from integer to pointer
 #define digitalPinToPCICR(p)        ( (((p) >= 0) && ((p) <= 31)) ? (&PCICR) : ((uint8_t *)0) )
/var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/endstop_interrupts.h:121:21: note: in expansion of macro 'digitalPinToPCICR'
       static_assert(digitalPinToPCICR(X_MIN_PIN) != NULL, "X_MIN_PIN is not interrupt-capable");
In file included from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/endstops.cpp:35:0:
endstop_interrupts.h:141:7: error: non-constant condition for static assertion
       static_assert(digitalPinToPCICR(Y_MIN_PIN) != NULL, "Y_MIN_PIN is not interrupt-capable");
In file included from /Applications/,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/HAL.h:36,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/MarlinConfig.h:39,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/Marlin.h:35,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/endstops.cpp:27:
/Users/rwillett/Library/Arduino15/packages/Sanguino/hardware/avr/1.0.3/variants/sanguino/pins_arduino.h:112:70: error: reinterpret_cast from integer to pointer
 #define digitalPinToPCICR(p)        ( (((p) >= 0) && ((p) <= 31)) ? (&PCICR) : ((uint8_t *)0) )
/var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/endstop_interrupts.h:141:21: note: in expansion of macro 'digitalPinToPCICR'
       static_assert(digitalPinToPCICR(Y_MIN_PIN) != NULL, "Y_MIN_PIN is not interrupt-capable");
In file included from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/endstops.cpp:35:0:
endstop_interrupts.h:161:7: error: non-constant condition for static assertion
       static_assert(digitalPinToPCICR(Z_MIN_PIN) != NULL, "Z_MIN_PIN is not interrupt-capable");
In file included from /Applications/,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/HAL.h:36,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/MarlinConfig.h:39,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/Marlin.h:35,
                 from /var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/endstops.cpp:27:
/Users/rwillett/Library/Arduino15/packages/Sanguino/hardware/avr/1.0.3/variants/sanguino/pins_arduino.h:112:70: error: reinterpret_cast from integer to pointer
 #define digitalPinToPCICR(p)        ( (((p) >= 0) && ((p) <= 31)) ? (&PCICR) : ((uint8_t *)0) )
/var/folders/6b/cdzfwv0j0mdgpg60zgl5k9n80000gn/T/arduino_build_238352/sketch/endstop_interrupts.h:161:21: note: in expansion of macro 'digitalPinToPCICR'
       static_assert(digitalPinToPCICR(Z_MIN_PIN) != NULL, "Z_MIN_PIN is not interrupt-capable");

Do you want to setup a github repository and I can help debug and compile? Your call.

Also happy to take this offline to avoid polluting this board.


Thank you, for reporting! This is a bug from the Arduino IDE building tool, since I use PlatformIO I was not getting this error.
I updated the code to keep this feature disabled by default for Arduino users. The compiled HEX versions will have the feature enabled.

Oh no! Not another toolchain :)

I was just about to set up my Mac for Ardunino command line development, e.g. emacs, make etc.

How do you deploy to the board after this, using progisp.exe or can you do it via Mac or Raspberry Pi or whatever?




Hi, I've downloaded the Fix version and spent the afternoon trying it out. There is definetly something weird in the code. Simply printing a skirt around the object shows the Z-Axis getting higher and higher and higher rather than laying the layer down. It finishes 80-100mm up in the air.

I've auto-homed, manually levelled the bed, set the Z_PROBE_OFFSET time and time again, When I print a simple calibration print it (a large thing flat square, when the extruder goes to the back of the bed, it just goes higher and higher.

I think the base Marlin 1.1.9 code has a bug in it when used with the BLTouch V3.1 as I'm finding issues that other people don't have. I accept I might have a dodgy machine but this consistently odd. It does appear that most people don't seem have the BLTouch V3.1 and have earlier versions which might have something to do with it.

I'm going to comment out ENABLE_LEVELING_FADE_HEIGHT and see if that does anything to help.


Turning off ENABLE_LEVELING_FADE_HEIGHT makes the auto bed level break. I end up with the Z Axis on the back row getting higher and higher. Works for the first two rows on a 3 x 3 grid.

I think that 1.1.9 is fundamentally broken for BLtouch V3.1 and that I'm now going to focus on either V2.x or the crap that Creality issues with the 1.1.6 release. If that doesn't work, then the BLTouch is going in the bin.

I'll try V2.x from you and see if that is any better. Not keen on the V2 release as it's so, so tight on space. I have ordered a replacement 32bit motherboard to see if thats any better.

Thank you very for taking the time to help.


Hi Rob,

I sent the latest version of the firmware to a friend in Spain with BLTouch 3.1 + standard Creality board. We could not reproduce this error, everything worked as expected.

I also reviewed the Marlin bug report system and could not find anything similar. The last bug fixed was related with the Z fade compensation.

I will keep looking for possible causes of this issue.


Thanks for the update. I wish you hadn't told me that your friend's identical setup works as this means I do have a problem :)


1.Am going to strip the machine back to the standard configuration, download 1.1.61 from Creality, build and install that so I have a (hopefully) working stock system. Check that I have no issues there with the 'standard' firmware.

Then I'll reinstall the BLtouch (or rather I'll simply leave the BLTouch in place but plug it back into the MB), install the pile of crap that is the Creality software and see if that works. T


Thanks for the update. I wish you hadn't told me that your friend's identical setup works as this means I do have a problem :)


1. Am going to strip the machine back to the standard configuration

2. Download 1.1.61 (non BLTouch) from Creality, build and install that so I have a (hopefully) working stock system. Check that I have no issues  with the 'standard' firmware.

3. Then I'll reinstall the BLtouch (or rather I'll simply leave the BLTouch in place but plug it back into the MB), install the pile of crap that is the Creality software with BLTouch and see if that works.

4. If that works ok, I'll then try and move to your software.

5. If that doesn't work, I'll go back to the standard non BLTouch software in 2 and await the 32bit motherboard.

6. If that doesn't work, I'll introduce my Thor hammer to BLTouch V3.1 and then the Ender 3 Pro :)

What annoys me is that I was getting very good prints without the BLTouch last Saturday. I have spend 3-4 hours per day for the last six days trying to get this to work and I've failed miserably.

<Sound of man pulling toolkit out and dumping it on the table>


Have gone back to stock, got it working and then moved to 1.1.9+Fix (your version) but no BLTouch.

Have levelled the bed and am now getting decent prints for the first time in a week. I've done so much levelling this week that I am now an expert on manual levelling. I need to spend the next month printing parts for a CNC machine so am going to leave it as-is as this is the first time it's worked since Sunday. It's looking good, so am assuming either:

1. My BLTouch is faulty. Seems to work OK for detection but you never know...


2. There is something in the BLTouch code in V1.1.9 that simply doesn't work for me, but does for everybody else. Life is sometime mean :)

I have a 32 bit board coming in the next week or so, so may try and use that but focus is on printing.

Thanks for the help.


Hi Rob,

For 32-bit boards you will be better served with the latest version of Marlin You better prepare your development station because a new version is released every two weeks and there are still several bugs to be solved.

Before retiring your BlTouch I recommend replacing all the wires and connectors and perform some additional tests. If the orange wire is damaged or suffering with EMI it will fail to transmit the high frequency data required for the bed leveling.



Thanks for the comments re BLTouch.  I have noticed that I am getting severe disconnection problems Octoprint and my board as well. The board is out of the enclosure on the Ender 3 as I am constantly attaching the ISP programmer. I'm wondering if I need to put it all back in the enclosure and get it shielded again and if that is anything to do with it. However the BLTouch cable has to be mostly external as it connects to the Z Axis wiring harness. I have ordered a load of ferrite rings to see if that helps.

I'll reassemble everything when I get the 32bit board and I can then load a bootloader and work a little bit more hands off.

At the moment it's printing stuff from MPCNC (Bottom corners) at the moment. Looks OK, so far, 14 hours to go <sigh>.



Thanks for taking the time to make the changes and set the 5V.

I've downloaded the hex first and reflashed the MB. Checked it had the right version number or rather it had changed. It had. Set the BLTouch 5V command and did an auto bed level.

The probe went to the middle and executed correctly. It then went to the first corner and did two tests and worked OK. I can see that you have set the probe for a 5x5 matrix.

First row OK.

First point of second row OK 2nd point OK, 3rd point OK, 4th and 5th points OK.

3rd row OK

4th row fails and the Z axis just keeps going up.

5th row fails and the Z axix just keeps going up.

I then downloaded the source and rebuilt it, I made some changes due to the X and Y Position of the BLTouch but left the rest untouched.

before I installed, I looked through the source code and can see this is commented out.


Should this be uncommented and set up for BLTouch V3.1?

It also talks about 5V tolerant controllers. Does this refer to the probe or the motherboard?

many thanks




Sorry but I am still getting the Z axis rising. It does the first two rows and then on the third row just keeps going up and up.

I have set the 5V bltouch but that seems to have made no difference at all. Its the same for the HEX file and for the compiled file.

I'm going to wait until my 32bit board turns up and then try again. At least one other person has reported the same problem as me which is kinda reassuring.

Thanks for your help, I now need to take it off again and setup the Z end stop.


I ran the 1.9 Firmware from a couple weeks ago, and was getting the Z always climbing issue.  Not always, sometimes it would work then it would just stop on the next print.  I think I have bltouch V3, but not sure (purchased from Antclabs Jan 2019).  I just upgraded to the +Fix version, had to comment out that ENDSTOP_INTERRUPT thingee to get it to compile.  It started working after reboot for one leveling operation and then resumed "bean stalking".  Any ideas for debugging?

Please try the update I posted this week. The entstop interrup feature compilation error is a bug from Arduino IDE, if you try Visual Studio Code or the pre-compiled HEX files you will be able to enable it and save your board processor, this will help you to avoid blobs in complex prints.

The updated version has extra options in the BLTouch menu, one of them is to enable the 5V logic. According to Antclabs the 5V logic compensates the capacitor in the endstop and might help to solve the probe problems.

Took me a bit to figure out how to upload via platformio/vscode with a USBasp gizmo.  For others with the same thing,  add this to [env:melzi]

upload_protocol = usbasp

; each flag in a new line

upload_flags =


It loaded successfully but an auto-home operation still has the Z axis going only upwards.  I tried to build v2, but it wouldn't fit on my 8bit board.  I have a 32bit on the way.  Appreciate any other suggestions.  TIA

Not sure if this helps, but for me the z-axis only went upwards when the probe was stuck for some reason. Usually a reset paired with manually pulling out the probe and then making sure it passes a few protrude/retract operations (usually 10) and subsequently turning the probe screw in 1/4 turn steps until it does made sure it worked. 

Die Endstop Interrupts feature as indicated in step 7 habe ich auskommentiert und nun arbeitet das Board wie es soll. Leider komme ich aber mit der Umstellung auf de nicht weiter, da der Sketch dann zugroß wird. Vielleicht lässen sich die Mesh oder RGB Zeilen auskommentieren damit der Sketch kleiner wird. Hat da schon jemand Erfahrung und kann helfen?

I commented out the Endstop Interrupts feature as indicated in step 7 and now the board is working as it should. Unfortunately, I don't get any further with the changeover to de, because the sketch then becomes too big. Perhaps the mesh or RGB lines can be commented out so that the sketch becomes smaller. Does anyone already have experience and can help?

Submitted by CF on Fri, 01/17/2020 Permalink



Thanks for the detailed conf. Seems as a perfect starting point for a noob like me usinf marlin and bltouch.

Could you give a short advice what to change for bltouch 3.1?




Submitted by Anonymous on Tue, 12/17/2019 Permalink

Here I have a small list of errors with this sketch.

ultralcd.cpp:3869:156: error: unterminated argument list invoking macro "_UxGT"

             MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(float43, MSG_FILAMENT_DIAM, &planner.filament_size[0], 1.5f, 3.25f, planner.calculate_volumetric_multipliers);

In file included from sketch\ultralcd.cpp:98:0:


sketch\ultralcd.cpp:3869:57: note: in expansion of macro 'MSG_FILAMENT_DIAM'

             MENU_MULTIPLIER_ITEM_EDIT_CALLBACK(float43, MSG_FILAMENT_DIAM, &planner.filament_size[0], 1.5f, 3.25f, planner.calculate_volumetric_multipliers);

exit status 1
unterminated argument list invoking macro "_UxGT"

Any Idea how to fix? Some of the "language" errors I can fix easely but all the rest? No idea. I'm thankful for any help on this.

Submitted by Anonymous on Thu, 12/12/2019 Permalink


in Make Magazin Germany they used your firmware (bugfix, configuration) for use with BL Touch ( Whats the background, why this firmware will not work with BLTouch 3.x ? In the article is nothing mentioned, regarding this issue?



Submitted by Celso Rossi on Mon, 12/02/2019 Permalink

Excellent job!

I installed on ender 3 and it was perfect!


Do you have these settings for Marlin 2.0 with bug fixes?

I am still figuring out what features from Marlin 2 I will port to this custom Ender 3 compilation. The problem is that due memory size restrictions, we get more features with 1.1.9 than with the 2.0.

EDIT: The Marlin 2.x version with BLTouch up to 3.1 is now available for download.

LATEST EDIT: The Marlin now support the BLTouch 3.x.

Submitted by Tobias on Wed, 05/29/2019 Permalink

hi! just want to say thankyou for this. helped me get bltouch working and functioning properly!

Submitted by mattes on Mon, 04/29/2019 Permalink


i get this error, when compiling your firmware for Ender3


unterminated argument list invoking macro "_UxGT"

what can i do ?


Do you have more details about this error? Did you modified any file or translation?

This error appears when the files are corrupted or some expression was left open.


Downloaded the package, rebuilt and recompiled from zero. No problems found!

Just to make sure, here are the library versions I used used:

  • Sanguino 1.0.3
  • U8Glib 1.19.1
  • Arduino IDE 1.8.9 on Windows 10

And here is the compilation stats:

Sketch uses 129176 bytes (99%) of program storage space. Maximum is 130048 bytes.
Global variables use 6657 bytes (40%) of dynamic memory, leaving 9727 bytes for local variables. Maximum is 16384 bytes.