Final Project (Main summary page)¶
Final Video¶
YouTube link for HD (https://youtu.be/xsKVT7ChrV4?feature=shared)
Final Slide¶
Electonics Design and Production¶
After considering all the components of my project and after many trail and a graveyard of boards, I made the final schematice for my board.
For my project I am using ESP32-Wroom-32/32U as microcontroller.
For my Input device I have: - 3.3V RFID CARD Reader and Cards
For my output device: - 12V Solenoids with 0.2mA - 5V DF mini player for audio output - 5V 6 Neo-Pixles
I used a buck convertor for 12 volts to 5 volts drop as regulator could not handle 7 volts drop but I also have a provision to use voltage divider with 2 no of 10UF capicitor. I used another regulator for 5 to 3.3 volts drop.
I have screw head connectors for all my output devices and horizontal connector for RFID. I also have male connectors for FTDI cable for programming.
Next was to plan out my ckt layout, which I did in a withboard.
After making the schematics and clearing all the ERCs, I started making the the board design. I had to use 12 R0 as jumpers in the ckt.
One change I would make to this circuit is to have 3 and 12 volts seperated as I can easily short my MCU if 12 volts get connected.
Using Roland SRM-20 and mods, I milled out my ckt board. I looks a little scratched as the bit had worn out at the end of fabacademy(achivement lol) after milling out countless boards.
After soldering, the board looks like this. I have both SMD and through hole components. The buck convertor input and output are connected to the board though wires going into holes with 1mm rivets.
All the screw head are strongly connected to the board though rivets.
Programming!¶
I was parallely doing programming for the board all though the Fabacademy assignment. I made sure to test each component in different weeks like, input, output, electronics design and also networking week.
For RFID reader, DF Mini Player and neo-Pixles I had to download libraries in Arduino IDE. You can go to Tools-> librabry manager and type the required library and install.
I also carefully selected the pins on my ESP32 and as some of the pins give me error while uploading code and also doesnot work. Pins to avoid are GPIO36, GPIO39, GPIO34 and GPIO35 as they are only input pins for it a NO for output.
Also made sure to use GIPO26 nd GPIO25 for DF MINi as they are Digital Audio Channel interfer while uploading vis FTDI which also uses UART communication. As for SPI communication, I used the designated pins in ESP32.
Also avoided using other RX and TX pin for output and Input pins as they
Here are the pinouts used in my code and design:
For my coding, I used array to hold my Card UIDs and Switch case to pop the solenoids and play audio.
I tested my code on a breadboard with ESP 32 Dev module to make sure my code works before actually redesigning my final board.
I worked perfectly.
Here is the Link to all the other trials and error to my final project coding and electronics which I tried to maintain. You will find some of the problems I faced and how I debugged them.
You can also check the links to my Electronics Design week,Embedded programming Week, Input and OutPut Week and Networking week for all indivividual coding and PCB design I did.
Design and manufacturing¶
3D design¶
I had made this cardboard design when i was conceptualizing my poject idea toward the begining of the classes.
I made around 3 designs before finally making this one as my final design. The design below has three parts which will be 3d printed seperately.
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The base which can hole the PCB which can be attached to the body with screws.
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The body with cone shaped speaker holder and bear on the outside though which the sound will come out and also slots for laser cut acrylic solenoid holder. It also has a power jack hole. The design was had in fusion360.
- The lid is aligned with the body, mainly the holes though which solenoid will pop out. It also has RFID holder which goes on top of the lid. The lid is also designed with slots for laser cut outer lid.
Design consideration that was made are the clearance required for perfect fit of the lid to the bottom was 0.1mm and also laser cut acrylic, kerf of of the laser was considered.
The solenoid holders fit too.
I also designed the letter so that RFID card fits at the bottom without notice.
Laser cutting¶
For substractive manufactufing process in my project, I choose laser cutting.
The lid which is 10 mm in height for the side wall and lid was designed for 5.2mm acrylic and also considered kerf of laser while designing.
The design was made in fusion360.
For the solenoid holder the design was imported from the main casing desing as DXF file and used for laser cutting.
Molding and Casting¶
I also decided to do molding and casting of mushroom head for solenoid head. The Mold was 3d printed and was also tested during the molding and casting week.
The design was made is fusion360 with top and bottom part. It is a 2 pard mold.
TOP:
Bottom:
The setting for the printer was 0.2mm detail on prusa slices with 10 % infill.
I used silicin as the casting material and add color to the silicon. I made use of syringe to inject silicon through the small hole it had at the bottom.
I made all the 6 mushroom at once and put inside the oven at 60 degrees for 1 hour and let it cool for 2 hours and it was ready.
This is one I had made prior to casting all 6 for testing.
Vinyl cutting¶
Finally…using roland SRM machine I cut out the name of my project made in Inkscape.
System Integration¶
I stared by testing to see if my acryics fit the printed parts.
Next, I started by screwing all the output device to the screw treminals on the main board.
After this, I screwed the bottom of my kit to the body.
Bill of Material¶
Answers and Planning¶
Here is the link to week 17 assignment
You can also find the project I found online which has a similar concept to mine.
Licence¶
I choose to go with Attribution-NonCommercial-ShareAlike Licence. I want people to be able to make their own pop braille to help those in need and also to spread awareness on the lack of tool avaliable to build inclusivity.
With this licence people can copy and redistribute whatever I have done and can also modify and build on it. However, the user cannot commercialize the product for financial gain. For any work used, the user much credit this work and me.
Here are links to legal code and deed to the licence
