One Wire Protocol Short Circuit

Using Arduino Project Guidance
#1

Hi everyone,

My project is regarding a emulated DS18B20 temperature sensor(Arduino Pro Mini) and a real Ibutton work on the same one wire bus.

Both emulated temperature sensor and real Ibutton work well. But when I turn off the emulated temperature sensor, the short circuit condition came out and I tried to remove the connection of emulated sensor from the bus and put it back again without on it, the short circuit condition disappear.

Can anyone help to explain this why will this happen?

Thank you.

Regards,
Nick

#2

If the Arduino is not powered, its port pins become roughly equivalent to one or more diodes connected to ground.

It is a bad idea to apply voltages to Arduino pins when it is not powered.

#3