XYZ limit switch pins on mainboard

Sovol Klipperized SV07
1

has anyone worked out what pins the 3 unused limit switch plugs on the mainboard go to and how they are wired? i did a bunch of continuity test tracing and while i got most of the pins i couldn’t work out those ones (or the one between the sd card slot and the usb c ports)

for those interested the rest of the pins are as follows, using the numbers from the manual:

  Board Port │ Manual Description    │ MCU Pin │ Notes                                    
 ────────────│───────────────────────│─────────│───────────────────────────────────────── 
  1          │ Z Limit               │ ?       │                                          
  2          │ Y Limit               │ ?       │                                          
  3          │ X Limit               │ ?       │                                          
  4          │ Bed Thermistor        │ PA4     │ analog in with voltage divider resistor  
  5          │ Chamber Thermistor    │ PC0     │ analog in with voltage divider resistor  
  6          │ Runout Sensor         │ PD11    │                                          
  8          │ LED                   │ PE10    │ 24V through MOSFET                       
  9          │ Case Fan              │ PD3     │ 24V through MOSFET                       
  10         │ 7025 Fan (back fan)   │ PE13    │ 24V through MOSFET                       
  11         │ Bed Power             │ PA2     │ 24V through MOSFET                       
  20         │ Shutdown Module       │ ?       │                                          
  22         │ No Limit/Limit switch │ ?       │ this is the dip switch

I also traced what I could from the 5x2 header next to the usb ports

     ┌──────┐
  5V │ 10 9 │ GND
PB15 │ 8  7 │ PB12
PB13 │ 6  5   PB14
   ? │ 4  3 │ ?
 PB2 │ 1  2 │ ?
     └──────┘
2

ok, i think i worked this one out too. the z connects to a pin directly with a pull up resistor (dont know how i managed to miss that before) and the X and Y ports connect to the same pins as their respective stepper drivers stall detection pins. these are switched with a BL1551B electronic switch (kind of works like a relay but i have no idea how since its not magnet based). these switches are controlled by both the dip switch on the board and a digital pin on the STM. that means that in theory you could use them as digital pins for input then switch them over while homing although i dont think this is a good idea.

i will do a full write up on this at some point but i have also emailed sovol to ask for the schematics or a true pinout diagram (not sure why i didnt do that earlier) so if they come back and send me anything useful ill use that instead (and post it somewhere)

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