# CPR Trainer Final

By: Daniel Bustamante and Joe Solimanto

Description

The CPR trainer project uses the accelerometer in a Wii Nunchuck to find the rate of compressions. The one set of LEDs uses the acceleration to show whether the compressions are reaching the correct depth, and the second set registers the amount of time between compressions (time and depth attained from health teacher and are .5 seconds a compression and 2 inches for the depth). Currently, the LEDs are set so the ideal compression depth and timing will light up the third LED. The LEDs are set so the minimum LED starts lit (which also shows if the nunchuck is upside down). Too much pressure and too long of compressions will light up the 4th and 5th LED, while too little pressure and too short of compressions will light up the 1st and 2nd LED.    Programming Description

The CPR trainer uses a nunchuck library attained online. This library allows the arduino to access the nunchucks data for acceleration and for the buttons. However, the CPR trainer program only uses one of the accelerations (which is why the nunchuck is on its side) For the CPR trainer, the program primarily uses if else functions to determine which LEDs will light for the depth. For timing, the programing once again uses if else functions, but this time it is based off a counter (millis) that starts when the program starts. Also, the if statement only measures for compressions that reach the ideal depth in order to avoid multiple points for a single compression.

The Program

#include <Wire.h> //pulls up wire.h library

#include "nunchuck_funcs.h" //pulls up nunchuck_funcs.h library

int loop_cnt=0; //adds loop_cnt as a variable

int t = 2500; //sets t as a variable

long time; //sets time as a large variable

long x = 0; //sets x as a large variable

long y = 0; //sets y as a large variable

long z =0; //sets z as a large variable

int d = 8; //sets d as 8

int e = 2; //sets e as 2

int a = 5; //sets a as 5

int b = 6; //sets b as 6

int c = 7; //sets c as 7

int f = 10; //sets f as 10

int g = 11; //sets g as 11

int h = 12; //sets h as 12

int i = 13; //sets i as 13

int j = 9; //sets j as 9

byte accx,accy,zbut,cbut; //sets accx,accy,zbut,cbut as bytes

void setup()

{

pinMode (a, OUTPUT); //sets pin a as an output

pinMode (b, OUTPUT); //sets pin b as an output

pinMode (c, OUTPUT); //sets pin c as an output

pinMode (d, OUTPUT); //sets pin d as an output

pinMode (e, OUTPUT); //sets pin e as an output

pinMode (f, OUTPUT); //sets pin f as an output

pinMode (g, OUTPUT); //sets pin g as an output

pinMode (h, OUTPUT); //sets pin h as an output

pinMode (i, OUTPUT); //sets pin i as an output

pinMode (j, OUTPUT); //sets pin j as an output

Serial.begin(19200); // arduino sends data back in 19200

nunchuck_setpowerpins(); //sets analog pins as ground and positive for nunchuck

nunchuck_init(); // send the initilization handshake

}

void loop()

{

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

loop_cnt = 0; // sets loop_cnt equal to 0

nunchuck_get_data(); // recieves data from nunchuck

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

if (accx > 160) {

digitalWrite (a,HIGH);} //if accx > 160 a is on

else {

digitalWrite (a, LOW);} //if accx< 160 a is off

if (accx > 183) {

digitalWrite (b,HIGH);} //if accx>183 b is on

else {

digitalWrite (b, LOW);} //if accx<183 b is off

if (accx > 190) {

digitalWrite (c,HIGH);} //if accx>190 c is on

else {

digitalWrite (c, LOW);} //if accx<190 c is off

if (accx > 205) {

digitalWrite (d,HIGH);} //if accx>205 d is on

else {

digitalWrite (d, LOW);} //if accx<205 d is off

if (accx > 220) {

digitalWrite (e,HIGH);} //if accx>220 e is on

else {

digitalWrite (e, LOW);} //if accx<220 e is off

if (accx > 190)

{

Serial.print("accx: "); Serial.print((byte)accx,DEC); //prints byte for accx when >190 Serial.print("time: "); Serial.println((long)millis(), DEC); //prints time for accx

x=millis(); //sets x equal to time in mseconds

z=x-y; //sets z equal to new time minus old time

if (z<1500){ //uses z only when difference of time less than 1.5 seconds

if (z > 100) {

digitalWrite (f,HIGH);} //when z >100 f is on

else {

digitalWrite (f, LOW);} //when z <100 f is off

if (z > 250) {

digitalWrite (g,HIGH);} //when z >250 g is on

else {

digitalWrite (g, LOW);} //when z < 250 g is off

if (z > 400) {

digitalWrite (h,HIGH);} //when z >400 h is on

else {

digitalWrite (h, LOW);} //when z<400 h is off

if (accx > 750) {

digitalWrite (i,HIGH);} //when z>750 i is on

else {

digitalWrite (i, LOW);} //when z<750 i is off

if (accx > 1000) {

digitalWrite (j,HIGH);} //when z>1000 j is on

else {

digitalWrite (j, LOW);} //when z<1000 j is off

}

}

y=x; //sets y equal to old time

}

loop_cnt++; //adds 1 to loop_cnt variable

delay(1); //delays for one microsecond

}

Problems

One problem encountered is the multiple data points for a single compression. So, if the arduino records two data points for a single compression, then the timing will register as too short. The best solution found so far is to only have the arduino register data above a certain acceleration so only one point will register for peak. However, this also creates the problem of too soft of compressions not registering a time. Currently, there is no solution we have found to having too soft of compressions register a time without having multiple points register for harder compressions.