Compressor won't start

[oddjob]

Originally Posted by kennypu

oh woops sorry about that, I tried both (1,1 and 4,2 because it came from an example), but neither worked. So the pressure switch isn't required to get the compressor running?

The software turns the compressor on even if the pressure switch is not wired. It's one less thing to go wrong when you are first testing, but you must use the pressure switch after things are working. Leave the selected digital port unconnected for now, just to be sure it's not preventing the compressor from turning on. As you suggested, I would try using the Relay class next. Something like this, untested:

  Relay *m_relay_1;

...

  m_relay_1 = new Relay(1);
  m_relay_1->SetDirection(Relay::kForwardOnly);
  m_relay_1->Set(Relay::kOn);