BIQU MicroProbe V2.0 not working

General Discussion
1

Basic Information:

Printer Model: Tronxy x5sa 400 pro
MCU / Printerboard: BTT SKR 1.4 Turbo
Host / SBC Pi4
klippy.log
printer (2).cfg (3.3 KB)
klippy (3).log (1.1 MB)

Fill out above information and in all cases attach your klippy.log file (use zip to compress it, if too big). Pasting your printer.cfg is not needed
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Describe your issue:

…I’m using an SKR 1.4 turbo controller with a micro probe v2. With my configuration, the way it is now, the probe does its self-checks on boot up, and the blue light stays on. It reports “TRIGGERED” in mainsail all the time and doesn’t respond to commands. I’m hoping someone here has some in site on this. It’s been driving me nuts for days now.
Thanks yall

2

The pin you are using is not suitable for this probe as it lacks any kind of pull-up. This probe requires a strong pull-up, so use, for example, E0Det (pin 1.26), which has a 10k pull-up.

3

so is that as easy as moving the wire and changing the pin in the config? Sorry, I’m fairly new in this area of nerding. Thanks a ton for your help BTW

4

So, I have an update after changing the probe pin to !1.27, it shows triggered with the probe up and open with the probe down. However, it still won’t respond to commands. I’m a bit afraid to try to home it without knowing if it’s working correctly.

2025-04-29 16_47_02-SKR-V1.4-Turbo-pinout.jpg
2025-04-29 16_47_02-SKR-V1.4-Turbo-pinout.jpg486×315 193 KB

5

Alright, here’s where I’m at. X and Y home fine, Z home says “Endstop z still triggered after retract.” Here’s my current log and a screenshot tof he output of the console

2025-04-30 00_42_31-Mainsail
2025-04-30 00_42_31-Mainsail433×117 5.69 KB

klippy (4).log (1.6 MB)

6

You seem to have a general issue with your endstops, particularly X and Y. Follow this link and, first and foremost, ensure that G28 X and G28 Y are working correctly.

Additionally, you have multiple instances of the following error:

Timeout with MCU 'mcu' (eventtime=125.968767)
Transition to shutdown state: Lost communication with MCU 'mcu'

This indicates a general hardware issue. Refer to Timeout with MCU / Lost communication with MCU.

Moreover, the MicroProbe is not a BLTouch, despite its resemblance. Neither the settings nor the commands for a BLTouch apply to it.

7

From your error msg it seems that your probe logic is set incorrectly:
BLTOUCH triggers HIGH and does not require a pull up resistor.

BIQU Microprobe V2 detection signal is open-drain output, and a pull-up resistor needs to be set. BIQU Microprobe V2 requires a pull up resistor because it triggers LOW.

Many users struggle to configure BL Touch to work - For other type main boards you have to physically unplug the Z stop plug and insert the BL TOUCH probe pins into the Z_STOP socket then configure firmware for the BL Touch probe logic to work.

The SKR 1.4 main board have a dedicated/specific BL Touch connector designed ON THE BOARD with sockets BL Touch connection. No need to change wires or unplug anything.

Additionally the deploy and stow for BL Touch is 10 and 90 - For BIQU Microprobe it must be 1 and 0.

Here are the Z pins as from Marlin:

BTT_SKR_V1.4
Function Pin Number Description
Z_MIN_PIN P1_27 Z-axis minimum endstop pin.
Z_STOP_PIN P1_27 Alias for Z-axis minimum endstop pin.
Z_DIAG_PIN P1_27 Diagnostic pin for Z-axis (same as Z_MIN_PIN).
Z_PROBE_PIN P0_10 Z-probe pin (when not using Z_MIN_PIN for the probe).
Z_MIN_PROBE_PIN P0_10 Z-axis minimum probe pin.
PROBE_ENABLE_PIN SERVO0_PIN Pin for enabling/disabling the probe.
SERVO0_PIN P2_00 Servo pin for the Z-probe (used for deploying and retracting the probe)
Z_ENABLE_PIN P0_21 Enable pin for the Z-axis motor.

Hope this helps :slight_smile: