Main Site Documentation

DS1820 on parasite power


#1

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 ?

#2

did you installed the pull-up resistor ?


#3

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…


#4

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


#5

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…


#6

Hi,

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

Any reply are welcome


#7

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.


#8

Thx for your answer… I also give up…

All the best,