ds18b20 causing power issues for uno?

hello,

it is the first time i am tinkering with ds18b20 temperature sensor. i wired it like this: https://www.tweaking4all.com/wp-content/uploads/2014/03/ds18b20-arduino-connected.jpg

but to my surprise as soon as i start arduino with sensor connected it immediately disconnects, power led flickers as if there was a problem with power. right after sensor disconnection, arduino continues function.

anyone can please hint me what could be the problem? i expected this to be rather a simple task.

br, jose

If you're sure your connections are like in the schematic, I think your DS18B20 is shorted. It should not drain that much power. According to the datasheet, max is 1.5mA.

thank you! i measured a way more current with multimeter. also, the 2nd sensor i have does not cause the issue.

how come that i do not detect a short-circuit with multimeter on ds18b20 itself? could it be that it only manifests itself when on power? is there a way how do i fix it (have the long - waterproof - version of it). kind regards,

jose

I think the short only shows up when power is applied. Are your two sensors the same type? There has been a lot of confusion regarding the cable colours on some of the waterproof DS18B20's Try to Google : waterproof ds18b20 wiring.

same type, same vendor, same order. colors are: red, black and blue. i only did a quick test with the 2nd sensor leaving out blue (which i believe is signal) disconnected.

I tried to make a search on the forum pages with 'DS18B20 wiring colour' and got http://forum.arduino.cc/index.php?topic=210118.0 as response. The 2'nd entry from el_supremo can be the same problem you are facing. So according to him, you should try to swap the red and the blue wire. Remember the pull-up 4.7Kohm from -5v. to the data pin (now the red).

/ffur

OOPs. The last line should be +5v. - sorry

OPs. The last line should be +5v. - sorry

You can edit your post. Use 'Quick Edit' or 'More (then Modify)' down at the lower right, next to 'Quote' on your own posts.

Don

Hi,

I have sold thousands of those sensors. Here is what I have found about colors:

---------------------( COPY )--------------------- Sensor Connections:

red (VCC) blue or white or yellow (DATA) black (GND)

Some Versions, like Adafruit, have these connections: Orange Stripe: (VCC) White: (GND) Blue Stripe:(DATA) -----------------( END COPY )----------------------

jose1711: same type, same vendor, same order. colors are: red, black and blue. i only did a quick test with the 2nd sensor leaving out blue (which i believe is signal) disconnected.

The signal line requires a pull-up resistor - omitting this might cause all manner of bizarre behaviour as the data wire is floating.