4. Embedded programming

In this assignment you will begin to see programming principles, where the objective is to develop programs that demonstrate the individual's knowledge and ability to program objects through a microcontroller. With this in mind, I will focus on programming with a focus on my final project, that is why I decided to program motors that will be the basis for moving the assistant robot, all through simulation.

Microcontroller data

The first thing is to know the information about the microcontroller that I am going to use, the esp32, so, based on the datasheet on this page (Datasheet), and the information in this image, it will be easier to know the types of connections and where I have to connect the esp32 with the other elements

Programming

To simulate the program and in turn the connections of the esp32 and other components, I will be working on the wowki page that provides easy tools for the electronic section, in addition to using the c++ programming language adapted for Arduino that is compatible with the ESP32

Another useful tool that "Wowki" offers us is information about the components that it provides us, providing information such as the connections of the component, its operation or even a certain programming base for it.

After making the connections of the components and making a test code, I get an error telling me that the library I use in the code does not exist.

So, I go to the "Library Manager" section, look for the corresponding library (ESP32Servo) and add it

I return to the code, run the program and observe that I no longer get errors and that the console shows me the data that I request, and with this information I have an idea of the parameters with which I can delimit the actions of the joystick to activate the motor

Once the data on the joystick inputs has been collected, I observe its maximum parameters, I add an "if" with the minimum that I want to exceed of those parameters, specifically the "vry" the upper part of the joystick and I add as an action that the position of the servomotor changes from 90 to 180 degrees when the joystick goes up and that it returns to its initial position when it is neutral

While programming my code, I realized that the servomotor might not be the best option to move my robot, since its rotation is limited, so I decided to use a stepper motor

For the connections, I was guided by the following image, where I could see that one more element is needed, an H bridge to control the motor

I started making the connections and looked at the pins I had to connect

I finished connecting the components, and modified my code to adapt it to the requirements of the stepper motor, such as adding the STEP and DIR input pins, the "motor" function that indicates that the motor advances at a certain speed and of course, the conditions to indicate in which direction the motor should move

In the video, you can see that when the joystick goes up, the stepper motor follows one direction, and when the joystick goes down, the direction of the motor reverses and turns to the opposite side.