Sanity/Skill Check

Hello Arduino Community. I am brand new to Arduinos and programing but have always been "techie". I recently had the idea of using an Arduino to control an exhaust fan in my garage based on two interior temperature zones and one exterior zone. Basically, if the exterior temp is X or higher and either of the interior zones is X degrees or higher than outside, the Arduino triggers the fan to turn on.

With no experience, I used ChatGPT to help me generate a parts list.

I'll limit the list to where I am at with the problem I am having:

Arduino Nano ESP32 with headers

Breadboard with jumpers

4.7 kilo ohm resistor

Three waterproof DS18B20 probes

Installed on the Nano:

OneWire

DallasTemperature

ChatGPT recommended the first step is to test the configuration with a single sensor vs multiple at the same time.

The Arduino powers up and communicates fine. I was able to upload the sensor test code (included later) with no problems. I uploaded and ran Blink just fine.

Using this pinout (confirmed with what is printed on the board) https://docs.arduino.cc/resources/pinouts/ABX00083-full-pinout.pdf

I have the power connected to 3V3 OUT (second pin on the left), the ground connected to GND (second pin from bottom on the left), and the data connected to D4 (the 9th pin down on the right). Between 3V3 out and D4 I have the 4.7 K ohm resistor.

I am not getting any sensor detection on the Serial Monitor. It does print that 0 sensors are found.

I have checked continuity in every direction, and on every piece I can think of. All of the jumpers are good; there is good power between 3V3 and GND, and between D4 and GND. I checked the resistor, and it is providing the correct resistance. The traces on the breadboard check fine. Finally, I have tried 3 different temp sensors and checked them for internal shorts. Because the resistor is going across the board, I added a piece of electrical tape to prevent any short-circuiting. Still nothing works. ChatGPT is saying I likely have a bad batch of sensors. But Im hoping someone more experienced can help me check this. I have ordered a couple of standard (non-waterproof) DS18B20's to check with, but they won't be here until tomorrow.

Here is the sensor test code: Sensortest.ino

I am open to any feedback or suggestions! Thank you all in advance.