Hello,
I am working on my first 1-wire network. So far I have been able to read temperatures from a few DS18S20 sensors on a breadboard. Lots of fun!
I am getting ready to construct the first leg of the network. I am not an EE, and really haven't played much with components in the past, so I have some questions about resistors.
I will be powering the sensors on pin 3 with the 5V provided by the master hub. I see that to do that, I need to provide a pullup resistor between the 5V and the DQ line. A couple of questions:
1. Do I only need to do this once on the network? Or do I need to do this at each sensor?
2. What resistor should I use? I've heard 4.7K, but then I've seen other people say that's too high.
Finally, I was wondering if I need to provide a resistor inline on the 5V line (pin 2 on the Hobby Boards wiring diagram), or does the master hub limit the amount of current on the line? If I need to provide one, I have the same two questions: only one for the network (pretty sure yes)? and what size?
Thanks for your help (and patience).
pk
I am working on my first 1-wire network. So far I have been able to read temperatures from a few DS18S20 sensors on a breadboard. Lots of fun!
I am getting ready to construct the first leg of the network. I am not an EE, and really haven't played much with components in the past, so I have some questions about resistors.
I will be powering the sensors on pin 3 with the 5V provided by the master hub. I see that to do that, I need to provide a pullup resistor between the 5V and the DQ line. A couple of questions:
1. Do I only need to do this once on the network? Or do I need to do this at each sensor?
2. What resistor should I use? I've heard 4.7K, but then I've seen other people say that's too high.
Finally, I was wondering if I need to provide a resistor inline on the 5V line (pin 2 on the Hobby Boards wiring diagram), or does the master hub limit the amount of current on the line? If I need to provide one, I have the same two questions: only one for the network (pretty sure yes)? and what size?
Thanks for your help (and patience).
pk