BIGTREETECH Pi V1.2 - Board Fan Pin Configuration

BIGTREETECH Pi V1.2 Fan Pin connection

On the user manual BIGTREETECH mentions pin PG19 for the 5V fan board but it's not right. 

TJ MacLennan provides the good pin on the Facebook BIGTREETECH Official group. (Thanks again)  

PG19 is definitely a GPIO pin. It may not be on the 40 pin GPIO header but any input / output pin on the BTT Pi and CB1 is GPIO.
The formula to convert from PG19 to GPIO is:
[(PG - PA)*32] + {Pin Number}
Where PA = 1, PB =2….so PG = 7
So [(7-1)*32] + 19 = 211

finally, the fan pin is gpio211. So now we can add the good pin on the Klipper config.
Be sure to mention "host" to make it work

ex:  pin: host:gpio211

Now let's configure this in Klipper!

add on printer.cfg new mcu :

[mcu host]
serial: /tmp/klipper_host_mcu

add a temperature fan for your BTT PI in printer.cfg : (this is an example, you can modify it easily)

[temperature_fan raspberry_pi]
pin: host:gpio211
kick_start_time: 0.8
#shutdown_speed: 0
off_below: 0.1
max_power: 1.0
#fan_speed: 0.6
sensor_type: temperature_host
control: pid
min_temp: 0
max_temp: 85
#max_delta: 5.0
pid_kp: 1.0
pid_ki: 0.5
pid_kd: 2.0
min_speed: 0.1
max_speed: 0.6
target_temp: 38

If you have an issue with this, try this : 

https://www.klipper3d.org/RPi_microcontroller.html?fbclid=IwAR07IYNk0_3k3UTf683JsdY7qgAgOjG8EIBKXrdl26PGByq5l3y30RgaajU#install-the-rc-script

Hope it can help, 

Happy printing!