05-24-2021, 12:39 PM
Nice, that looks easier to work with than the Ehiem.
Maybe the pins next to J3 and J4 is the power from the batteries, if so you can power up feeder there and check the left and right side of S4 to see if it's a ground or +3v or whatever. If one side is ground you can connect the data wire to other side of switch but if it's positive voltage you'll need to change the NPN to PNP like this.
![[Image: P-Channel-Same-Voltage-with-Pull-Up.png]](https://www.baldengineer.com/wp-content/uploads/2019/04/P-Channel-Same-Voltage-with-Pull-Up.png)
Maybe the pins next to J3 and J4 is the power from the batteries, if so you can power up feeder there and check the left and right side of S4 to see if it's a ground or +3v or whatever. If one side is ground you can connect the data wire to other side of switch but if it's positive voltage you'll need to change the NPN to PNP like this.
