120 Beacon St, Somerville, MA 02143
Grab a Pen with the NeuroMaker Hand

Welcome to programming the NeuroMaker Hand using C++ programming! In this project, we are going to create sample code that will allow us to make finger movements that will allow us to grasp a pen and other small objects!

Estimated Time

Approximately 1 hour

Number of People

1-4 students for each available NeuroMaker Hand

Necessary Supplies

  • One fully built NeuroMaker Hand
  • One MacOS, Windows or Chrome OS computer
  • Arduino Online Editor with Arduino Create Agent fully installed
  • A pen, pencil or other small cylindrical item to grab with the hand

Necessary Program Files

  • Please see the code breakdown in the below instructions

Preparations

  • Please ensure that the NeuroMaker Hand has working batteries. Additional power lights on the power board of the Hand should turn on when the on/off switch has been turn on. If your fingers move erratically or don’t move it all after uploading the below code this could mean that your batteries are running low.
  • Please ensure that the Arduino Create Agent and Arduino Online Editor are safe listed on your district firewall. Instructions for IT personnel is provided here: Arduino Editor Safe listing Guide
  • In case you have not yet installed the Arduino Editor, please complete the Set Up C++ Coding Environment Project

Background

Most prosthetic hands used in the assistive technology field don’t move each finger individually. Instead, each hand gesture a patient wishes to make is provided as a set. For instance, if an amputee wishes to pick up a piece of paper or a pen, that person would press a button or complete a different command that would produce the necessary gesture. Manipulating each finger individually like we do with a natural human hand is very laborious for someone working with a prosthetic. Keeping this in mind, we are going to produce a specific gesture in order to pick up a pen or other small cylindrical object. Upload your code to the hand and see what you can pick up or what other modifications you can make!

Project Instructions

Please follow the instructions in the following presentation walkthrough!

Grab a Pen with the NeuroMaker Hand Walkthrough

*Please note, in case objects slip out of your NeuroMaker Hand, consider adding some friction to the fingers with a rubber glove, tape or other materials.

For your convenience, the code in this project has been provided below:

/*
This program uses the index finger and thumb to grab a pen.
*/

//include the servo library to control the servo motors
#include <Servo.h>

//create 5 servos in an array
Servo servos[5];

//set up servo motors of fingers

void setup() {
  //servos 0, 1, 2, 3, and 4 move the thumb, index, middle, ring, and pinkie fingers respectively.
  servos[0].attach(6);
  servos[1].attach(5);
  servos[2].attach(4);
  servos[3].attach(3);
  servos[4].attach(2);
  
  //place hand is in starting position
  startingPos();

  //wait 3 sec (at this point, place pen between two up fingers)
  delay(3000);
}

void startingPos() {
  //servos close all fingers except thumb and index
  servos[0].write(0);
  servos[1].write(180);
  servos[2].write(180);
  servos[3].write(180);
  servos[4].write(0);
  return;
}

void loop() {
  //close fingers to grab pen
  servos[0].write(180);
  servos[1].write(0);
}

 

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