DS1820 on parasite power

My application uses a DS1820 (onewire interface) on parasite power.
Without parasite power (3rd wire connected to +5V), it works fine but I get 00AAh reading when using parasite power.
Some questions :

  • Which pullup output port setting is used by the OneWire driver ?
  • Is it possible to instruct the OneWire driver to pull the output port high during a long(er) time interval ? (if yes, how ?)
  • Any tips on how to solve this problem ?

did you installed the pull-up resistor ?

Did you remember to connect the DS1820’s power pin to ground?

It must be connected to ground if it isn’t connected to +5V…

Yes, I installed an external resistor, as described in the datasheet of the DS1820.
The 3rd lead is connected to the ground.

So pin one and pin three is connected to ground.
Pin two is connected to +5V through resistor.

What value is the resisitor? Maybe try 1K…


Any solution for this problem? I am in the same situation… how to handle parasite power with Netmf.

Any reply are welcome

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I’d also like to know if anyone got it working.

When cerbuino came out - I beat my head against a wall trying to get it to work with parasitic power… never got it work. I had a glimmer of hope - I suspect the answer is in the timing/dwell time to query the DS1820.

Thx for your answer… I also give up…

All the best,