Build an IoT Temperature Monitor

Humberto Arredondo Perez
CE 351 - Fall 2020

In this class we developed an IoT Temperature Monitor to get real temperature from our location to a website. To achive this goal, we used and followed a tutorial provided by Dr. Li. We used 2 arduinos nano, a wifi module, a sensor for temperature and a display to see the temperature in real time.

Methods and Materials
First, we paired up the ssd1306 OLED module to the arduino nano and display some graphs made by Adafruit in Figure 1.

Figure 1. Oled module graphics display.

Then, we change the code to only display text because we did not need graphics for this application (Figure 2).

Figure 2. OLED showing only text.

After getting the code with only text, we connect to the arduino nano a sensor to keep track of the temperature. We used the Dallas DS1820 which is a high quatity sensor. Then, we run the code and checked for the temperature display in Figure3.

Figure 3. Code to paired up the Dallas sensor and displaying temperature values.

After learning how to connected the Dallas sensor and the OLED module, we connected them together so we can see the temperature in the display instead of the serial monitor, which is more practical. The result is showing in Figure 4.

Figure 4. The temperature value is obtained but the DS1820 and sent to 328p microcontroller in arduino, then send it to the ssd1306 Display module.

Now, using an example of ISR while the temperature is being display was the next task to do. We code in arduino and while the temperature were been display in the OLED, we started to blink a LED every 40 seconds. the result is shown in Figure 5.

Fugure 5. Blinking an LED while displaying temperature and using 1 wire communication.

Once we had temperature been displayed, we add the ESP8266 wifi module to send the data to a website on line called ThingSpeak to have it display in real time there, so we can check the temperature remotly (see Figure 6).


Figure 6. Code, circuit in the bread board and the display results in ThingSpeak.


Fugure 7. Temperature monitor in ThingsSpeak.

Figure 8. ERC is showing no errors.

DRC in the layout showing no errors.


In this project we learned how to build a temperature monitor using some well known components such as Arduino nano, OLED module, WIFI module ssd1306, ESP8266 and how to used SPI communication protocol (using 1 wire). we also explore on the usage of a master and a slave for the arduino nanos. Overall, it was a really fun proyect to take a used of all this new components that are out there in the market at low cost.