Description: This sealed digital temperature probe lets you precisely measure temperatures in wet environments with a simple 1-Wire interface. The DS18B20 provides 9 to 12-bit (configurable) temperature readings over a 1-Wire interface, so that only one wire (and ground) needs to be connected from a central microprocessor.
Note: The pinout for this sensor is as follows: RED=Vcc BLACK=GND WHITE=SIG
Dimensions: Probe is 7mm in diameter and roughly 26mm long. Overall length (including wire) is 6 feet.
Based on 18 ratings:
1 of 1 found this helpful:
I was emailed by SFE to write a review on this sensor. I had wired it (I thought) per the instructions and it didn’t work. I read the data sheet on the internal part and it seemed to suggest that a pullup resistor was only needed if the part was scavenging power from the data line. Since I was giving it 5v on the red wire, I didn’t think that applied to me. After entering my initial (unhappy) review, I read some of the other reviews. I didn’t see others having (many) problems and one reviewer noted that he had to add a “10k pullup”. I did that and it worked! I’m now happy :-) and will try to figure out how to run 2 sensors off a single Arduino port.
Have you contacted our technical support department @ firstname.lastname@example.org - they are usually pretty good at getting things like this working, and if they can’t help you get it working they can help you setup a replacement sensor for you.
1 of 1 found this helpful:
The example code SparkFun supplies is not the best, but with a bit of tweaking it could work okay. I would much rather suggest this library as it also supports multiple sensors (and does not try to use some LCD display): https://github.com/milesburton/Arduino-Temperature-Control-Library
Also, the standard One Wire library in the Arduino Library Manger is required.
This was my first actual experience with 1-Wire. The description seems to indicate that “no external components are needed” and you just need to wire it up and go. Not exactly. A pull up resistor is required between the white data line and red power line. I threw a 10k in there, but I have seen lower values used. For whatever reason, I was unable to get the AVR internal pull up to work with it.
The nice thing about 1-Wire and this component is you can put a bunch of these all on just one pin. They each have a 64 bit unique address (which you need to “discover”). I was able to get 3 sensors going by connecting power, ground, and all the data lines to to Pin 7, for example.
2 of 2 found this helpful:
Just took it out of the box. Sure would be nice if there was a little piece of paper that told which wire was which. I’m going to guess: Red = V+ Black = GND White = Data But why make me guess?
1 of 2 found this helpful:
Easy to connect got it working in less than 30 minutes.
Easy to connect and very sturdy. Keep in mind you have to allow for the thermal characteristics of the plastic coating. Very flexible cable
0 of 1 found this helpful:
This is a great encapsulation of the DS18B20. We would buy it in the thousands if we could get a data sheet for it for UL. I have been told there is no data sheet available so we will have to use another device.
I am using these to monitor the temperature in a bread proofing box - one embedded in an electrically heated layer of bricks, and one in a pan of water which gives me a warm moist environment for raising bread. It’s powered by a PICAXE 18M2+ processor with the AXE133Y OLED display, and switches power (120 VAC) off and on to the 150 watt snow-melt cable embedded in the bricks.
I have tested them with my RaspberryPi and work great!
Nearly perfect. Sturdy construction. Very easy to configure for use with the Raspberry Pi… maybe 5-10 min max. This sensor requires shielding in order to be used outdoors, but that’s not a big deal. My only disappointment is the cable length is short. It’d be great if it came in different sizes.
Most of the time, this sensor returns the correct temperature, but… (1) About 1 in every 30 readings, the sensor doesn’t respond to the 1-Wire device search. (2) About 1 in every 50 readings, the sensor returns 65535. (3) About 1 in every 100 readings, the sensor returns a reading 0-20C off from the actual temperature.
These are usually pretty solid little units. If it seems to be acting inconsistently, I’d recommend getting in touch with our tech support team. They should be able to help you out.
Makes it super easy to measure temperature.. 1 wire bus is sweet too..
I used to think that this was too expensive until I realized how long it makes me to make them myself and now think it is well worth the price.
These temperature sensors are very easy to hook up, and the measurements they give are accurate.
These work great and I like the 6' lengths. I’ve had problems reading 3 shorter ones I bought from Adafruit.
Quick, and easy installation and operation