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Topic: can't get anything on DS18b20 temp sensor. (Read 1 time) previous topic - next topic

Nick_Pyner

Have you tested that power is getting to the sensor, i.e. the breadboard is kosher? I have heard of dud sensors but never experienced it. There have even been stories of DS18B20s not actually being DS18B20s. perhaps a better way of ensuring they are is to get them properly packaged, like this http://www.ebay.com.au/itm/10pcs-3m-10ft-Durable-Waterproof-Digital-Temperature-Temp-Sensor-Probe-DS18b20-/331287537189?hash=item4d2246a625:g:J5UAAOxyOypSWq-v
You can get them with female terminals too, but I prefer bare wire with soldered tip and a screw terminal block.

Sagirokach

I don't need it waterproof or at this length... do you have any other listing that are with the tiny head? I also have a space limitation.
I'll buy 1 from a local store and I'll see if it's the sensor fault or the wiring. But until I do get one if you think something I did was wrong then please let me know what to check.

Nick_Pyner

Your wiring looks kosher, and your code is kosher, hence my comment. Just stay away from parasite power.

Budvar10

Show the real photo of your wiring, just one sensor without parasite power.
Arduino clone with ATmega1284P   http://forum.arduino.cc/index.php?topic=277260.0

Sagirokach

Ok wait isn't that what I posted?
The non parasite option?
Because as I understand it I posted the regular option of the wiring in a link above.

Sagirokach

ok I bought 2 sensors from a local store and now it found them....

so probably a bad batch.... where can you see the batch?

Thank you all for trying to help me with this!

Budvar10

#21
Nov 10, 2016, 02:47 pm Last Edit: Nov 10, 2016, 02:49 pm by Budvar10
Ok wait isn't that what I posted?
Sorry, I missed it.

Congrats, I am glad you solve it.
Arduino clone with ATmega1284P   http://forum.arduino.cc/index.php?topic=277260.0

el_supremo

If they are real DS18B20 sensors, they should have writing on the flat face of the device which should look like this:
DALLAS
18B20
1218C4
4007A

The first two lines are obviously the important ones. If there's no writing at all, it's probably a dud, one way or another.

Pete
Don't send me technical questions via Private Message.

Sagirokach

on 9 of the 10 I have this written:

DALLAS
18B20
1541C4
+233AA

And those won't engage.

the last one has this written:
DS18B20
1433B1
MALAY
507AF

and this one will get extermly hot when I put it in the right way as the other and as the new sensor that I bought today.

so about the other 9 what can be the problem?

Budvar10

#24
Nov 10, 2016, 07:54 pm Last Edit: Nov 10, 2016, 07:56 pm by Budvar10
Apparently correct figure does not mean anything. The fakes on ebay frequently looks like original and in addition they works. Some time ago it was very discussed chip FT232RL. It has exactly same package. Firstly there was visible difference in printed label and mark while original has it engraved by laser. Lately, the fakes was also engraved. Fake chips works so normal user cannot recognize between. FTDI released the drives which disabled fake FT232. It means internally they differs.

Arduino clone with ATmega1284P   http://forum.arduino.cc/index.php?topic=277260.0

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