Week 2-8    ATMega 328 Advanced Applications

Introduction

In this lecture, we learned how to interface the MCU with an ESP8266 module, how to transfer the sensor's data to ESP8266 and display it on an IoT platform like ThingSpeak, and how to intferface the nano with the DS18B20 temperature sensor and the SSD1306 oled module.

Task 1.1

In Task 1.1, we got started by using the ssd1306_128x64_i2c example in the Adafruit SSD1306 library, which displayed an animation, images, and texts on the SSD1306 oled module as shown in Demonstration 1.


Demonstration 1: Demonstrating ssd1306_128x64_i2c example.

For our purposes we only need the text display function so by getting rid of the useless code we were able to display the text only, as shown in Demonstration 2.


Demonstration 2: Demonstrating of using only text from ssd1306_128x64_i2c example.

Task 1.2

In Task 1.2, we downloaded the onewire and milesburtonTemp libraries. Then we used the DS18B20 temperature sensor and the arduino nano to read the temperature from the sensor and

display it using the serial monitor as shown in Figures 1 and 2.


Figure 1: Setup using arduino nano and DS18B20 temperature sensor.


Figure 2: Using the nano and DS18B20 temperature sensor to display temperature.

Task 1.3

In Task 1.3, we altered the setup in Task 1.2 to include the SSD1306 oled module so that we could display the temperature read from the DS18B20 temperature sensor, as shown in Figure 3.


Figure 3: Using the nano,DS18B20 temperature sensor, and SSD1306 oled module to display temperature.

Task 2

In Task 2, we used an ISR while displaying the temperature on the SSD1306 oled module. We used several different communication techniques like UART, I2C, and OneWire. In

Demonstration 3, the LED will blink every 4 seconds while still displaying the temperature on the SSD1306.


Demonstration 3: LED will blink every 4 seconds while still displaying the temperature on the SSD1306.


Task 3.1

In Task 3.1, we were introduced to the ESP8266 WiFi module. The module allows for microcontrollers to connect to a WiFi network and make simple TCP/IP connections. In this task, we used

the master, SSD1306 module and DS18B20 sensor to display the temperature on the SSD1306 module, as shown in Demonstration 4.


Demonstration 4: Demonstrating of using only text from ssd1306_128x64_i2c example.

Task 3.2

In Task 3.2, we built an IoT based temperature sensor. We were able to do this by having a master and a slave. The master ran the script that was used in Task 3.1, where it used the

SSD1306 module and DS18B20 sensor to display the temperature on the SSD1306 module, while the slave ran the script to manage the WiFi connection to ThingSpeak, as shown in

Demonstration 5.


Demonstration 5: Demonstrating of using only text from ssd1306_128x64_i2c example.


Task 5

In Task 5, we were given the task to design the schematic and the PCB layout of the system in EAGLE. I had to create parts for the ATMega328 surface mount, the DS1820, the ESP

module, and the SSD1306 module which I was able to put into a schematic as shown in Figure 4. Then I was able to convert the schematic to the BRD view as shown in Figure 5, and finally

was able to route the wires and pour the copper on the PCB as shown in Figures 6 and 7.



Figure 4: Schematic of IoT temperature monitor while running ERC check.


Figure 5: BRD layout before wiring of IoT temperature monitor.


Figure 6: Brd of IoT temperature monitor that is wired and DRC check has no errors.


Figure 7: Finished PCB.

Discussion:

By completing these tasks it gave me a better understanding of the ESP8266 module, DS18B20 temperature sensor, and the SSD1306 oled module. I was also to understand ISR a little better, and now see the use for it. I tried to attempt to implement push buttons to change the WiFi AP username and password but it did not turn out as expected. I was able to complete the PCB, but unfortunately I ran out of time to produce a PCB that implements the pushbutton system to change the WiFi AP username and password, but I might come back to it later to see if I can get it working.