Ah, didn't know this dc-dc-converters.Yes all thermistors have common ground.I have 4 so i need 2 ADUM6401.
The central heating connections are:AF1 = 0 volt groundAF2 = outside air thermistorKF2 = furnace thermistorVF2 = underfloor heating water thermistorBF2 = hot water storage tank thermistor
The ADC chip means i read the voltage on the Arduinos digital inputs?Do you have an example circuit diagram to give me a kick-start?
For the evaluation board i think you mean this one: http://www.analog.com/en/evaluation/eval-adumqs/eb.htmlBut it's a little bit to difficult to get here in Germany.
It means i need a 74LVC1G125W5 for every device now that uses SPI (SDcard, Ethernet...)?