DigitalHeroMeter

Tired of measuring distances with rulers, meters and other boring stuff? Here the solution that cool Heroes use!

A really cool gadget that you can wear like a glove of Iron Man, easy to develop, quite functional and ridiculously easy to use. Adjustable speed of reading, comfortable and durable. I've seen a lot of these devices, but not like this one. The structure hold the hardware and is completely 3d printed and I used some Arduino components and Programming. In addition to this, is quite simple to upgrade the model with LEDs and a buzzer to give other indicators to the users, I really recommend this project for education as it's so simple to develop.

I hope you like it!

Supplies

1 x Arduino

1 x Ultrasonic sensor

1 x Potentiometer 10k

1 x Breadboard Mini

1 x 220 Ω Resistor

1 x LCD 1602 Module

14 x Jumper Wires

4 x Female-to-Male Wire

1 x 9V Battery

1 x Snap on connector clip

35 cm Velcro tape

10 cm Spiral cable organizer

1 x Screw driver Phillips (x)

1 x Screw driver slotted (-)

8 x Self tapping bolts M2 x 6 mm

2 x Self tapping bolts M3 x 12 mm

1 x Super glue adhesive

Step 1: System Design

The basic idea of the design was to incorporate a cool gadget on my right hand, but with the condition that the ultrasonic sensor had to read the distance straight on my right hand and at the same time the screen had to be in front of me, in order to see the current distance.

First I've decided to sketch the idea first to clarify how the system will look like and then I started to look for existing designs to avoid wasting so much time designing all the pieces. What I found are the following pieces:

The Arduino case ( top and bottom ) https://www.thingiverse.com/thing:994827

LCD Housing ( box and cover) https://www.thingiverse.com/thing:3557950

Ultrasonic sensor housing ( top and bottom) https://www.thingiverse.com/thing:1170335

But with these designs, something very important was missing "the grip" therefore I designed the missing piece and I modified the Ultrasonic sensor housing in order to include the 9v battery and the Breadboard Mini on Tinkercad.

Step 2: 3d Printing the Pieces

In this project I used the Original Prusa Mini 3d printer and its software Prusa Slicer. It took me 4 times to print all the pieces. If you have never use this printer and its software in the following website link there are really nice and well-documented tutorials on how to do it https://www.prusa3d.com/prusaslicer/

I printed the pair pieces ( arduino box, lcd housing, ultrasonic housing) and finally the grip, to 3d print pieces it's important to take into consideration that the disposition of the pieces is very important to reduce the printing time and the unnecessary supports.

Step 3: Circuits Design & Programming

In this step, I wanted to know all the necessary cables, components and mostly the disposition of the all hardware and finally test the system to make sure there were no errors. In order to do this I used again tinkercad but this time I used the circuits feature. It was really useful to previously develop the functional prototype on this virtual platform because gives a lot of clarity.

Basically I connected an Arduino board with an LCD screen, a mini breadboard, a potentiometer and a resistor but tinkercad offer an option that all these components are already connected in the option Arduino starters and then click on the LCD option which is shown in the picture. The next step is to connect the ultrasonic sensor to the circuit, it's really important to use the HC-SR4 type, because is the most common and it has 4 pins. To connect the Ultrasonic sensor just take into consideration Vcc is connected to positive 5V, GND is connected to negative 0v or GND Arduino port, the trigger pin is connected to port 7 and the echo pin is connected to the port 6 of the Arduino board, but you can actually connected to any of the free digital ports.

Programming

Once you drag the LCD circuit on tinkercad the code is upload it as well, it means that most of the code it's already developed and you just need to integrate the code of the ultrasonic sensor. Therefore I integrated the code on the following file.

Step 4: Assembling and Connecting the Circuit

The very first step is to integrate all the electronics inside the 3D printed pieces while connecting the cables in the correct order, otherwise it might be possible to repeat twice any step, therefore I started assembling the Arduino board inside the 3D printed box and fixed it with the 4 Self tapping nuts M2 x 6 mm.

Then I connected the Mini Breadboard with the LCD screen leaving a empty spot for the future connection of the potentiometer and I assembled the LCD with the 3D printed cover using 4 Self tapping nuts M2 x 6mm.

The next step is to connect the ultrasonic sensor with positive (Red cable), negative (black cable), trigger (orange cable) and echo (yellow cable) and then attach the housing box with 2 Self tapping nuts M3 x 12 mm.

Now is time to be patient and to connect the rest of the cables between the Arduino Board and the Mini Breadboard an the potentiometer, in order to do it without confusions I converted the previous tinkercad circuit from the standard Breadboard to the Breadboard Mini ( Take a look the picture above). Before to start, it's important to take into consideration that to connect the cables from the Breadboard Mini to Arduino, the cables go through the Arduino box cover, otherwise you will realize that you did include the cover and you'll have to repeat the process again.

Once everything is connected, the assembling time has arrived! In this step I sticked the LCD housing box with the cover with superglue and the result is impressive, it fits really well. In the next step I cut several velcro tapes to fix the ultrasonic sensor, the Arduino box, the LCD housing box and the grip support and I joined all the pieces.

Finally I included the 9V battery inside the hole and I connected the Power jack, to improve the cable stettics I covered the cables with Spiral cable organizer.