CPR Trainer

By: Joe & Dan

January 6th 2010

We had decided to come up with a CPR training dummy that would show the user if they are doing the chest compressions the right way. This could be done by using the Nunchuck from a Wii gaming system and an arduino board. The nunchuck is placed on the inside of the dummy and connected to the arduino through analog pins 5,4,3, and 2 as Inputs via an adapter found Here.

The Library was found on the same website

The code that we are currently using is:

#include <Wire.h>

#include "nunchuck_funcs.h"

int an[] = {11,12,13,11,12,13,10,13,10,12,10,11,10,9,9,11,12,9,8,11,8,10,8,9,8,7,9,7,10,7,7,11,12,7,13,7};

int ca[] = {12,11,11,13,13,12,13,10,12,10,11,10,9,10,11,9,9,12,11,8,10,8,9,8,7,8,7,9,7,10,11,7,7,12,7,13};

int loop_cnt=0;

int t = 2500;

byte accx,accy,zbut,cbut;

int ledPin = 13;

int x=0;

void setup()

{

for (int pin =7; pin<=13; pin++)

{

pinMode(pin,INPUT); // Set as input

}

Serial.begin(19200);

nunchuck_setpowerpins();

nunchuck_init(); // send the initilization handshake

Serial.print("WiiChuckDemo ready\n");

}

void loop()

{

if( loop_cnt > 100 ) { // every 100 msecs get new data

loop_cnt = 0;

nunchuck_get_data();

accx = nunchuck_accelx(); // ranges from approx 70 - 182

accy = nunchuck_accely(); // ranges from approx 65 - 173

zbut = nunchuck_zbutton(); // show data everytime the Z button is pressed

cbut = nunchuck_cbutton(); // show data everytime the C button is pressed

x = nunchuck_accelx(); // sets variable x = nunchuck_accelx

x= map(x,0,255,0,35); // sets variable x = map(x,0,255,0,35)

delayMicroseconds(t); // sets delay to variable (t)

pinMode (an[x], OUTPUT); // declares an[x] as an OUTPUT

pinMode (ca[x], OUTPUT); // declares ca[x] as an OUTPUT

digitalWrite(an[x], HIGH); // set an[x] to HIGH

digitalWrite(ca[x], LOW); // set ca[x] to LOW

delayMicroseconds(t); // sets delay to variable (t)

digitalWrite(an[x], LOW); // sets an[x] to LOW

digitalWrite(ca[x], LOW); // sets an[x] to LOW

delayMicroseconds(t); // shows variable (t) for delay

pinMode (an[x], INPUT); // sets an[x] as an INPUT

pinMode (ca[x], INPUT); // sets ca[x] as an INPUT

Serial.print("accx: "); Serial.print((byte)accx,DEC);

Serial.print("\taccy: "); Serial.print((byte)accy,DEC);

Serial.print("\tzbut: "); Serial.print((byte)zbut,DEC);

Serial.print("\tcbut: "); Serial.println((byte)cbut,DEC);

}

loop_cnt++;

delay(1);

}

Conversions for the serial monitor:

+1g = 180

-1g = 72

0g = 128

-2g = 0

+2g = 255

This is a calculation of the amount of G's that are being experienced.

So when it's not moving, the normal force = the force of gravity which is 0g (not moving).

y = 63.75x + 128