Vktech10pcs 3M Waterproof Digital Temperature Temp Sensor Probe DS18b20

I bought these about a year ago and used them connected to a Raspberry Pi single board computer to make a temperature logger. They worked great! Ten foot cables are very flexible and the metal tip provides good thermal conductivity to the surface being measured - I used aluminum tape for this purpose. I didn't test if they are in fact waterproof, but the heat-shrink tubing appears tight around the metal tips - so probably yes. I didn't check accuracy, but since these are basically a one chip solution - temperature input to digital output - the chip manufacturer's spec probably applies.In the logger application the sensors are all connected in parallel to the GPIO pins on the Pi - super easy. In theory, you can connect a large number of sensors to a single Raspberry Pi, as long as the cable lengths are managed properly. I had no trouble reading 10 sensors with one Pi. More details on how to build the logger including Python code can be found on the 'Instructibles' website. Just search for "Raspberry Pi Temperature Logger DS18B20".

I use DS18B20s daily but only wired in single wire protocol (parasitic mode) and I have ordered these exact ones over 26 times(260+ probes) because the preformed flawlessly; that was util recently The past THREE 10pks I have received do not wire for single wire parasitic mode and all the legs must be wired individually not even a pull up resistor fixes it. The probe always reads invalid or shorted when in parasitic mode. I have even tried multiple configurations of wiring in case the leads were attached to the wrong leg but to resolve. The quality of DS18b20a has drastically dropped in 2022 from Vktech.

Discoverd 2-3 degre celcius difference at «room temperature, and at my use in temp around 50-60 degrees C, one was about 10 degrees to low and one was about 10 degrees to high

Nice long cables, when tested against each other they were all within 1 degree as a lot. They have been running more than a year non-stop with no issues.

I’m using these in some custom house temperature sensors, both inside and outside. Three are used in my outdoor heated cat house, for our unfortunately outside cat. I measure air temp, the heated bed, and ambient cat house temp, and it just works. I have a lot of experience with the 1-wire devices, and in this case I am using an ESP8266 with cost of firmware to send data once a minute. It’s been working for 9 months without issue.

None of these sensors work. I tested all 10 and not a single one worked. I verified my test platform by using other sensors I purchased in the past and they worked just fine. After running several tests to try to get these working I gave up. I saw others who have purchased these more recently have had issues as well.

They work well with the raspberry pi 1-wire interface for reefpi or similar.

Perfect - using with my PI to monitor my pool temp!