Central Heating Controller

I hadn't seen those Solid State boards before - as @mhoneywill says, it might be a bit close for the pump. What about these guys. Same thing, but massive massive overkill :)

A 10m cable may be ok, but make sure you use a twisted pair of the cat6 as I guess noise could be an issue. To make it better, you could send a 5v signal rather than 3.3v.

To do that:

• Choose a 5v-capable pin on Espruino
  
• Add a 5k pullup resistor from the pin to 'Bat' (if running off 5v)
  
• Call pinMode(MyPin, "opendrain")
  
• Now when you output something, you'll get the full 5v voltage swing.