ENGR351 Lab 2020 Fall
Homework 3 - Advanced IoT Devices (ESP32)
Ryan Jeanes
Email: rejeanes@fortlewis.edu

Sending Acceleration Data Between Two ESP32s
For a lot of projects that require gathering a lot of data points over a long period of time, the ability to safetly store your data to use for data analysis later  is one of the most important parts of a research project.
To demonstrate a way to do this, a circuit was created using 2 ESP32s, an MPU6050 accelerometer, and a microSD module.
Materials and Methods

The breadboard circuit consisted of 2 ESP32s, an MPU6050 accelerometer, a microSD module, an Elegoo MB V2 power regulator, and 2 10K resistors. The accelerometer functionality was tested, followed by testing the SD card module, with the results shown in a video demonstration and figure 1, respectively. Once both modules were proven to be functional, then the ESP32s were coded to communicate the Accelerometer data over ESP-now to be written to the microSD card for data analysis using python. The code used for both the ESP32s and data plotting is shown here.

Figure 1 - MicroSD test
Figure 1 - SD card test

The acceleration data was succesfully transmitted from the master ESP32 to the slave, and the slave ESP32 succesfully wrote each axis of the acceleration data to the microSD card. The plots of the acceleration data with unprocessed acceleration values and processed acceleration values  that range from -4g to 4g.

Figure 2 - Raw acceleration data
Fig 2 - Unprocessed acceleration data recorded from MPU6050

Fig 3 - Proccessed data recorded from MPU6050
Fig 3 - Processed acceleration data recorded from MPU6050

There was a minor issue with the initial breadboard circuit, where powering both the ESP32s with a USB cable was not providing enough current for the slave ESP32 to function properly. Using an elegoo MB V2 power regulator fixed this issue, and the ESP32s were able to function as expected.