Thanks for sharing this! Using with same board you have (SB2209 RP2040) and used the FAN/IND port as well. For others curious, this is a 3-pin PH2.0 header. I wired with positive on the top pin and negative on the bottom pin (controlled by GPIO6), with the middle pin empty.
I'm using it as a "temperature_fan" in Klipper with temp set at 55C, which means the fan comes on automatically when the CAN board reaches 55C.
Before this, the SB2209 board was running in the mid to high 70s (75-78C) or about 30C-ish over the chamber temps. Now running in the lower 60C range after a 3-hour print, so easily 10-15C difference. I love the use of a blower fan, as they are readily available in 24V varieties, and it makes for a compact/slim design. Nicely done!
