Of course. Let me know how you’re getting on.

The idea with the first valve is to drive it with an H-bridge. This allows for reversing polarity and is commonly used with motors to allow for spinning in two directions. This requires 4 MOSFETs. I’m not sure what type of MOSFET you are using but if you can find a simple dc motor to test this setup you can verify that it works with the one you have before you extend the circuit to an H-brigde configuration. This would be cheaper than buying another valve. You’d need two GPIO pins and careful design to not short circuiting the H-bridge.

So the setup you have is not going to work. Even if you managed to get the valve to engage, it’ll require a negative voltage pulse to disengage according to the specs you linked above.

Could you clarify a few things? The circle symbol is meant to represent the voltage supply? Is it connected correctly? When you say solenoid, you mean an electromagnet, right? If so, why does it require that specific pulse with? You say you swapped out the LED for the coil, was the LED tested with MOSFET and diode in place? Does the solenoid engage when you take the connection off the RP2040 and drive it high directly? How did you ascertain the functioning of the solenoid by means of measuring resistance?