Week 18: Applications and Implications

What will it do?

The robot will help little kids learn a bit how to code by using a button matrix with symbols that they can use to code to make the robot move by following the sequence they have made. This is the first part of a bigger project that will continue being developed. 

My final project idea has always been something to make kids learn about either Robotics or Electronics. At first I wanted to make a fully modular robot, with parts that will be connected on top of it to learn about how electronics work (and it is still part of the whole thing, just not this spiral of development yet). At the end of Fab Academy, I have come to a decision to make only 3 main parts inside the whole robot: the screen that will have the GUI of the robot, the button matrix that will act as the input of the commands, and the motors, which will help it move. 

 Who's done what beforehand?

There is a lot of development around educational robots that honestly this list alone could take the whole page and all of my time to explain. My main inspiration have been some things I have worked with in the past, like the VEX123 robotic kit for little kids, LittleBits, Microbit and so on. 

Some examples from Fab Academy that I saw go into this direction as well are here!

http://fabacademy.org/2020/labs/talents/students/sarah-alghofaili/presentation.mp4

https://archive.fabacademy.org/archives/2017/fablabamsterdam/students/60/finalprojectpage.html 

What will you design?

I plan on designing the main body of the robot, which will be a little encasing for the whole parts that has 2 main wheels and a 3rd one to help keep balance in the front. The whole thing is being designed using Fusion with some models that are part of the system being grabbed from GrabCAD library and Thingiverse where needed. 

What materials and components will be used?

Packaging

Most of the materials regarding the packaging of the robot will be 3D printed and some laser cut, the bottom of the robot, which will hold all of it together will be of a MDF wood of 3 mm of thickness to make things be secured, the front and back are 3D printed to make the electronic parts fit in the exact place they need to go. There will be some screws used for securing things, but the side and front panels are planned to be press fit into the bottom panel. This is also thinking that the thing needs to be easy to build and needs to be easy to disassemble.

Electronics

There are 4 different boards made for the electronics portion of this project. One main board, which has the core of the robot which is a Raspberry Pi Pico, as the embedded microcontroller, it also has the whole communication with the ILI9341 which is the Display used to show the UI and also as the main input device for users to send information to the robot. It also has five 2 pos terminal blocks and two 2x2 connectors to help make external boards come into this main one. There is a voltage regulator for the main board as well, because the Pico and the display work with 3.3V as operating voltage and the Batteries used are 2 Li ion 2000mA 3.7V ones, which make the total voltage up to almost 8V. 

The other board made is the H-bridge that will control the Motors of the project. This consists of an IC named L293D and also has 7 connectors and one 5V voltage regulator.

The other board made was a button matrix, consisting of 4 buttons with their respective pull down resistors with some pinheads for connections with the main board. 

The last board was one made for distribution of Power. It consists of one Jack connector that allows the Battery holder to be plugged in and a 2x3 connector that will help connect the boards that need the power. The jack will be connected to the battery holder.

Where will they come from?

Packaging

The filaments and MDF for the packaging will be provided by the Fab Lab. The silicone for the wheels is also something provided by the lab.

Electronics

Some of the electronics used in the project are part of my personal collection of components, and things I have purchased thinking in this project in particular, like the Raspberry Pico, the ILI9341, and the 2 gearbox motors with the IC bridge. The smaller components, most of the terminal blocks and the PCB will be provided by the lab.

How much will they cost?

The BOM here presented is of all the boards that were made. 

 *** This is not the place where it was bought, the component is nonexistant in ElectronicaPY anymore, it was the closer found that has same carachteristics as the one used in the project.

What parts and systems will be made?

Main Board 

This one will contain the Pico microcontroller and the ILI9341 Screen. It will also have connectors to the other boards as well via connectors on the sides. 

Motor Driver and wheels

There are the 2 motors that are connected to the 3d printed rim and the casted tires, with the h bridge controlling it.

Power distribution

There is a battery holder connected to a small pcb that will be where the distribution of power happens.

Button Matrix

Buttons are made with a TPU filament so they are easy to push, and the matrix is a little pcb made with SMD buttons and connected via wires to the main board. 

What processes will be used?

2D and 3D design

Parts will be made with 3D design and print, like the front, and case of the robot, also the buttons and the rim of the wheels, as well as the idler wheel.

The 2D and subtractive design come with the base of the robot, which will be made with MDF wood, using the laser cutter, which will help the robot be more robust. 

Electronics design and production

There will be 4 boards made with PCB production using the Fusion electronics design tool for creating the Schematic and PCB as well as the 3D versions of each to make the integration with the packaging design. 

The CNC code preparation will be done using FlatCAM, where one of the boards will be a 2 sided PCB.

The milling will be done in the MODELA PRO MDX540.

Embedded microcontroller interfacing and programming

Most of the programming I want to do in C++ because I find it to be way easier to control variables there and there is a lot more documentation on most of the things. So, I will use Arduino IDE 2.3 and will see to use some examples that go in the direction of what I want my project to be like. 

The interface will happen in the Screen, and hopefully there will be a touchscreen.

System integration and packaging

All of the project was designed and planned in Fusion and it was a great tool to make decisions before putting things to the test, specially the PCBs where designed to fit inside the spaces made for the robot to hold things. The boards are all connected with special connectors that grab the wires strongly making it difficult for the project to break easily. 

 What questions need to be answered?

What is the process of making an ILI9341 screen work?

Is the touchscreen really essential for the project to be successful?

How can I program an H Bridge successfully?

What can I have as special sensors if the project works out quickly?

How can I make this project be even a greater tool for kids to learn?

How will it be evaluated?

The robot will be completed if:

• 

  The wheels can have 3 main functions> move forward, move right and move left.

• 

  The screen shows an easy to understand user interface

• 

  There is a way for the users to interact with the interface be it the touchscreen or another input like buttons.

• 

  The interface shows the sequence that the user inputs when the robot starts moving.

The evaluation for this project will be tested with kids that will use the robot and see if they can understand how it works without much explanation and play with it. If they feel it is an easy to use robot, the thing is a success! 

This test will be conducted in my school in one of my classes with kids of 1rst Grade that have also used something similar beforehand (Vex 123) and they will compare both robots. 

Project Development

What tasks have been completed, and what tasks remain? 

The 3D model of the first prototype, that shows where the wheels will go and where the PCBs are supposed to go, is finished. What remains to be done is the testing of the electronics and integrating all of it inside of the packaging.

 

  What's working? what's not?

The molds are working, I have the tires, still missing the rims. 

The first version of my main board worked! I managed to make a 2 sided pcb board

What is not working is my H bridge, I've been trying to work with a very tiny IC that was hard to solder, and is not moving the motors. The screen hasn’t been tested with the touchscreen.

 

 What questions need to be resolved?

Most of them, projects and stuff are still in development.

What will happen when?

I have a schedule made for the following weeks. This week I have off at work so I will advance a lot. 

• Mon: finish designing the pcb for the h - bridge and integrating everything in the 3D design

• Tue: mill and solder the pcb for the hbridge

• Wed: Make the first version of the PCB with the Modela.

• Thu: Test the Pico with the main board with the h bridge that was done on monday

• Fri: make plate with new h-bridge for motors since on Thursday during the test it was noticed that one of the pins of the extra small plate had been left short. I aimed to make a new board (make both joints now to make the work easier), mill and test if possible.

• SAt: enter the open time to ask questions about how to present the presentation and video and comment on progress made so far, listen to other realities in order to feel more pressured (?). Do this in the laboratory if possible.

• Objective: finish testing with the motor board if it is not finished by Friday, and start doing programming tests, test the touch of the display and start putting together the skeleton of the main program from that. Work in parallel when programming gets complicated and you need a break (work in the design).

• Sunday: assemble the main code for movement and control of the robot after finishing the display tests on the screen, having the program tested for the last week, finishing final details.

This week I have to go back to work, so my work will be cut short in some parts.

• Mon: (4 hours of work from 4:30 to 9 approx.) finish programming tests already having the mosaics

• Tue: (3 hours of work from 5:30 to 9:30) make final version in Blue and with a more child-friendly design. Print in blue if possible. 

• Wed: (all day of work) join all the parts and start making beautifying details. Start putting together the video

• Thursday: (3 hours of work) design and build the box

• Friday: 4 to 9 (5 hours of work) make ppt and video. 

• SAB and SUN: put documentation in order to upload to the page. 

• Mon and Tues: FINAL TOUCHES GIVE ERROR ROOM HERE UPLOAD EVERYTHING THAT WILL BE READY ON TUESDAY.!!!

*update, this schedule suffered from many changes during the week because of things not working out in my favor, so honestly, sometimes even with a lot of planning things can go super wrong.

 

 What have you learned?

I have learned that sometimes planning ahead and trying to give yourself a schedule doesn’t matter because things break and don’t work like you want them to.