How To Make A Bionic Finger

complete bionic finger

Why Bother?

A bionic finger is a fun and simple, if you follow the instructions, thing to build and code to imporove your mechanical and coding abilities. It is fun to make and even more fun to use.
Bionic fingers are challanging enough that when you complete it you will feel really great when you finish it.

Say I Would Want To. How Do I Build it?

The first thing you will need to do make sure you have all your equiptment functioning (it is really frustrating when you have everything set up and your flexsensor doesn't work.
Next you put together your finger. This can be done by taking your string and threading it through the holes in your finger's parts. Make sure that when you pull the string the finger bends with it. Remember to hot glue the string to the tip of the finger when you are happy with it. DO NOT SUPER GLUE YOUR FINGERS PARTS TOGETHER IT WILl NOT BEND
Next what you have to do is tie the string to the moter.
NOw is when you stop to look at the other stuff in your equiptment pile. You should have an Arduino Uno (that circut board thingy), a FlexSensor (long bendable plastic peice that has 2 wires coming off it and a battery plug (it is a round plug with a peice at the end with 2 metal attachers). DON'T TOUCH ANY PART OF THE BATTERY PLUG TO THE ARDUINO IT WILL FRY IT AND IT WILL NOT BE PLESANT FOR ANYONE. YOU WILL HAVE TO GET A NEW ONE
Plug these thing is exactly where I tell you to or you will have some issues, minor or major depending. Look at your arduino. There are numbers and letters written next to the pins (those spiky thing). Do you see them? Good. Now pick up your FlexSensor and plug the two cords into the A0 pins. The A part of A0 means analog, this is what will make you finger mimic the moves of your real finger. It doesn't really matter which side each cord goes in but neither cord goes in the middle pin of that row. The battery plug needs to go in the large black bay. This is what will give your arduino its power. If you are unsure what the bay is then ask someone because if you get it wrong your arduino gets fried however, there is really no way to mistake it's the only place where it could be plugged in belivable. Now go back to your moter and take the cable attached and plug it in to the pin set labeled 9. For this it does matter how you plug it in. On the side of that row there are 3 letters: G, V, S. 'G' is the only one you have to worry about as it is how you will know how to plug your cable in. 'G' stands for Ground. So remember Brown Goes In Ground The brown cable gets plugged into the side with the 'G'.
Look back at your arduino and double check the numbers of the pins, it's hard the first time, it's worth it. Besides if you get the numbers wrong the coding doesn't work. But anyways
Now add the code and play. I would recomend putting it as far away from you and infront of a cat and moving the FlexSensor. The results of that are halarious.

Wait... You Mentioned A Code?

The code. Good catch.
The code is slightly more complicated but I will explain it too you line by line.
//Include Servo Library
#include Servo.h
Servo myservo; //create servo object to control a servo
void setup() {
// put your setup code here, to run once:
myservo.attach(9); //attaches the servo on pin 9 to the servo object
//Configure flex sensor pin
pinMode(A0, INPUT_PULLUP);
Serial.begin(9600);
}
void loop() {
// put your main code here, to run repeatedly:
int flexSensor=analogRead(A0);
/* Values from sensor are about 380 -> 550;
we need to convert this to about 0 -> 170
since my finger is too sshort to be affected
when the servo moves 180 degrees*/
int angle=(flexSensor-450);
Serial.println(angle);
myservo.write(angle);
}
//add video in here