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DS18b20 not found

PostPosted: Tue Sep 13, 2016 6:36 am
by Manowar
The task is to get data from ds18b20 and send it through the internet using mqtt. First tried it via C in eclipse, ds18b20 was detected correctly but i couldn't publish through te internet, only in local network. Then i tried Arduino ide, it sent all correctly but another problem - ds18b20 not detected. So what's the problem??? I thought about problems with DS, but with C code it works well.

Re: DS18b20 not found

PostPosted: Tue Sep 13, 2016 4:16 pm
by martinayotte
Do you have a 4K7 PullUp on the data line ?

Re: DS18b20 not found

PostPosted: Wed Sep 14, 2016 2:22 am
by Manowar
No, i don't. But when i had done it via C, this part worked well.

Re: DS18b20 not found

PostPosted: Wed Sep 14, 2016 12:52 pm
by martinayotte
You should ! :ugeek:
Probably the library you used in plain C were enabling the internal PullUp, but I recommend to still using external one, since for long wires, the OneWire specs require 4K7, far from internal one which is around 100K.