BD Sensor not working with SKR mini e3 V3

[Atreta]

I got very interested about this sensor and i just bought one bd sensor and i'm having difficulties using it on a SKR e3 mini v3.
I compiled my own firmware following the instructions from the github., but when i try to make an auto home it moves the x and y axis as it should, but when it tries the Z axis it raises it by about 1mm and stops.
I tried with the z end stop removed from the board and also installed and the behaviour is the same.
When i try to calibrate i get read error: check connection and delay. It isn't showing the "bd: xx" distance also. only shows the printer is ready.
If i flash the firmware with bd sensor and all other changes for it disabled, the auto home works normally.
Thanks in advance.

[markniu]

Which pins is the bdsensor connected to? it seems like the board can't communicate with the BDsensor.

[Atreta]

Thanks for the reply, it's connected to PC14 and to PA1 on the z probe socket.

[markniu]

As a test, you can try the pins on the exp1 connector. and use the M102 S-1 to check the connection first.

[Atreta]

I switched the pins to the EXP1 socket, now the printer is moving the Z axis down as it would when doing an auto home, but it halts the printer because the probe isn't detected. The calibrating program still won't detect it. Also the probe isn't overheating anymore.
how should i edit the pins?i'm using PB9 as sda and PD6 as clock, is it right below?

#define I2C_BD_SDA_PIN PB9 // Please change to the actual number which the SDA wire is connected to your mainboard
#define I2C_BD_SCL_PIN PD6 // Please change to the actual number which the SLK wire is connected to your mainboard
#define I2C_BD_DELAY 20 // default value is 20, should be in the range [10,30].

thanks a lot.

[markniu]

Did the bdsensor return the version string after M102 S-1?
and I can not find there has PD6 in the board schematic

[Atreta]

No, it didn't show the version yet.
This is the the schematic for exp1 on the skr mini e3 v3

[markniu]

another way is to increase the delay value, for example #define I2C_BD_DELAY 30

[Atreta]

I tried to use the tft pins and it didn't work, after that i tried the I/O pins and it behaved the same way when I tried to calibrate. It shows an empty bd version and the "read error check connection and delay" message.

[suroh1994]

@Atreta What firmware are you running? I have a SKR mini E3 V3 with the bd sensor connected to pins PB8 and PD6. In case it helps, here is my BDsensor config segment from my klipper setup

[BDsensor] 
sda_pin: PB8
scl_pin: PD6
delay: 10
z_offset: 0
x_offset: 0
y_offset: 24
no_stop_probe: 
position_endstop: 1.38
collision_homing: 1 
collision_calibrate: 1
speed: 3

[xMikyx]

@suroh1994 Can you tell me the connection for all the cables where you connected them. Because the Z-probe port does not recognize the BD sensor. But I have the regular version and not the M version of the sensor, so I do not have an additional circuit for exp1. How do I connect all the cables (GND, 5v, CLK, GND, SDA). Thanks for the help.

[markniu]

you can try to use the SPI connector on that board, for example: PA13 -- SDA , PA5 -- CLK

@suroh1994 Can you tell me the connection for all the cables where you connected them. Because the Z-probe port does not recognize the BD sensor. But I have the regular version and not the M version of the sensor, so I do not have an additional circuit for exp1. How do I connect all the cables (GND, 5v, CLK, GND, SDA). Thanks for the help.

[xMikyx]

@markniu it doesn't work. I also tried on exp1. and everywhere I get the same result "No data or corrupt data from BDsensor( ), Please check connection". Did I connect the cables wrong, which I don't think I did because I followed the markings on the probe. I also tried changing the cables and the same problem. On the M119 command the probe is always with:TRIGGERED. Is there a fault in the probe?

[suroh1994]

@suroh1994 Can you tell me the connection for all the cables where you connected them. Because the Z-probe port does not recognize the BD sensor. But I have the regular version and not the M version of the sensor, so I do not have an additional circuit for exp1. How do I connect all the cables (GND, 5v, CLK, GND, SDA). Thanks for the help.

Don't worry about the EXP-style connector on the M Version, that one doesn't work with the SKR e3 V3 anyways, since it will cause the board to be stuck in reset (at least the v1.1 that I have), since its SDA pin would be wired to the boards RST 😓

I've used jumper wires to connect the pins directly to the bottom four pins of the EXP1 connector. If you take a look at the pinout from the BTT github page (https://github.com/bigtreetech/BIGTREETECH-SKR-mini-E3/blob/master/hardware/BTT%20SKR%20MINI%20E3%20V3.0/Hardware/BTT%20E3%20SKR%20MINI%20V3.0_PIN.pdf) it says at the bottom right EX1. These are the pins I've used for my probe. If you look again at my config, I've wired the SDA to PB8 and CLK to PD6. GND and 5V obviously go to GND and 5V. See if this works for you and let me know if you need any further information.

[markniu]

How about the LED on the sensor?
I think the sensor should not be fault if the led is work as expected and the case of the sensor is not hot

[xMikyx]

@suroh1994 @markniu this is clear to me. I tried the same thing myself. according to the diagram which is given to the connector on the probe itself, I connected the cables according to this information to the z-probe output. I also tried on exp1 but here I see only one gnd connection. The probe uses 2 gnd connections. Where did you connect the second gnd cable? Besides, I don't know how to solve this because I have a screen connected to exp1 so the output is already full. I wanted to mess with this sensor because it says that you can connect it to the same place as the bltouch.

As for the LED, when I approach the table the LED is constantly on.