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Topic: Unable to use an UNO as a slave 1-wire probe (driving bus low issue ? ) (Read 151 times) previous topic - next topic

destroyedlolo

Hi all,

I'm working on a project to use an Uno as 1-wire probe in order to publish some humidity data.

My test network is 10cm long and is driven by a DS2484 at 5v.


If I put a second probe on the network (tested with a DS28EA00), both the DS28EA00 and my Arduino are detected and I'm able to read Arduino's data.

But, I have only the arduino on this network, it is not detected anymore : I can see from its console it's receiving and handles 1-wire RESET signals ... but its response is not seen by the head.
I suspect the Arduino GPIO is too weak to put 1-wire bus low. Do you have any tips for such situation ?

My code can be seen here : https://github.com/destroyedlolo/OneWireArduinoSlave/blob/master/examples/DS18B20_SHT31/DS18B20_SHT31.ino

Anyone have any idea to solve this nasty issue ?


Thanks

Laurent

pylon

Do you have the pull-up from the data pin to 5V? Post a wiring diagram.

destroyedlolo

??? My response didn't appeared so ... another try.

I don't need pull-up on the 1-wire side as it's already embedded into the DS2484.
I'm using the same schema as appearing on Maxim's page.
Additionally, it's working with "normal" probes like DS18B20 or DS28EA00 :)

GolamMostafa

I don't need pull-up on the 1-wire side as it's already embedded into the DS2484.
The pull-up resistor has to be brought into action with the help of the following configuration register.

destroyedlolo

The DS2484 is managed from OWFS on my Linux box and I guess it's done as the DS28EA00 is working.
The issue is really at 1-wire side :)

destroyedlolo

Well, I move my pseudo probe to my main network with dozen of probe on it and a DS2482-800 and it working this time.
So I'm pretty sure the DS2484 signal is too strong for the arduino.

Anyway, I'm continuing my dev and will try to solve this issue afterward.

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