I went ahead and bought the controller, but I’m going to need to control my valves. I have the following valves.
5 2-Way CR3-02 Control: control line is done by connecting the ground
1 2-Way CR3-03 Control: control line requires 12V
1 3-Way B3 Wiring Control: 3 wires with 2 lines that take 12V and switching between them determines position.
I’m trying to figure out the best way to make a simple circuit to control them. I’ve borrowed form the brewpi valve controller, but included a ULN2803A to control the sinking of my control lines. I’ve made a crude schematic that’s attached. Any comments would be welcomed. This certainly isn’t something I’m good at.
I expect that this will require custom code to control all of the DS2408 lines properly.
Why not just hook a ds2408 up to an 8 channel relay board to handle all the connections you need. The relays are optically controlled and can control separate voltages and can be either nc or no wired. Just google “sainsmart 8 channel relay”
I don’t think a relay will work. Maybe it will, but here’s how I have to control most of my valves.
I expect that most relay boards always have the GND active. The ULN2803A is there control the ground for the bulk of the valves that are CR3 02 wiring. I added the SN754410 to the circuit to handle the 3-way valve and the one 2-way valve that need a sourced control line. I could have gone directly to a relay board for those, but if I’m going to the trouble I figured I’d add the SN754410.
If you have the knowledge to build what you need. The by all means make a custom controller. But any where in your schematic that you have to switch either power or ground a relay will do the job. As long as the amperage doesn’t exceed 10amps.