Hello everyone,
I am currently working on a project that takes weight measurements from a urine bag for hospital purposes. The project using a load cell and a HX711 amplifier in order to take the load from the bag. I use the values taken from the cell in excel to create some result graphs. The problem is that when I am trying to add liquid on the bag and is moving I am getting false results. Is there a way to use a gy-521 accelerometer to discard those values the time the bag is moving? Thank you
Here is my code:
#include "HX711.h"
const int LOADCELL_DOUT_PIN = A0;
const int LOADCELL_SCK_PIN = A1;
HX711 scale;
float calibration_factor = 227.0; //=100g
float output;
int readIndex;
float total=0;
float average=0;
float average_last=0;
const int cycles=20;
float readings[cycles];
void setup() {
Serial.begin(9600);
Serial.println("Date & Time, Weight *g");
//Serial.println("HX711 calibration sketch");
//Serial.println("Remove all weight from scale");
//Serial.println("After readings begin, place known weight on scale");
//Serial.println("Press + or a to increase calibration factor");
//Serial.println("Press - or z to decrease calibration factor");
scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
scale.set_scale();
scale.tare(); //Reset the scale to 0
long zero_factor = scale.read_average(); //Get a baseline reading
//Serial.print("Zero factor: "); //This can be used to remove the need to tare the scale. Useful in permanent scale projects.
//Serial.println(zero_factor);
}
void loop() {
scale.set_scale(calibration_factor); //Adjust to this calibration factor
//Serial.print("Reading: ");
output=scale.get_units(), 2;
//Serial.print(output);
//Smoothing the results
// subtract the last reading:
total = total - readings[readIndex];
// read from the scale
readings[readIndex] = scale.get_units(), 2;
// add the reading to the total:
total = total + readings[readIndex];
// advance to the next position in the array:
readIndex = readIndex + 1;
// if we're at the end of the array...
if (readIndex >= cycles) {
// ...wrap around to the beginning:
readIndex = 0;
}
// calculate the average:
average = total / cycles;
average=scale.get_units(), 2;
//Zero drift compensation
if((average_last>average+0.03 || average_last<average-0.03)){
//Minimum Load defines Zero-Band
if (average<0.06){average=0;}
//Serial.print("\tFilter: ");
Serial.print(",");
Serial.print(average);
average_last=average;
}
else{
//Serial.print("\tFilter: ");
Serial.print(",");
Serial.print(average_last);
}
//Serial.print(" g"); //Change this to kg and re-adjust the calibration factor if you follow SI units like a sane person
//Serial.print(" calibration_factor: ");
//Serial.print(calibration_factor);
Serial.println();
if(Serial.available())
{
char temp = Serial.read();
if(temp == '+' || temp == 'a')
calibration_factor += 10;
else if(temp == '-' || temp == 'z')
calibration_factor -= 10;
}
}
