Trying to make change in weight readings cause a decrease in computer volume

Other Hardware Sensors
1

Hello! Im making a project where if your weight shifts on a load cell scale, it makes the audio in my computer decrease.

So far, Ive built a working, reading scale with 4 load cells hooked up to my Arduino Rev3 Uno. Im trying to translate those readings through python to have a reading decrease the volume on my macbook. (At this point, I am at least trying to get any weight to decrease the volume, and then hoping I can work from there to alter it to any change in weight reading..)

Thing is, I cant get the readings to trigger a VolumeDown command through Arduino IDE. Heres my code so far:
#include "HX711.h"

#define calibration_factor -7050.0 //This value is obtained using the SparkFun_HX711_Calibration sketch

#define LOADCELL_DOUT_PIN 3
#define LOADCELL_SCK_PIN 2

HX711 scale;

void setup() {
Serial.begin(9600);
Serial.println("HX711 scale demo");

scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
scale.set_scale(calibration_factor); //This value is obtained by using the SparkFun_HX711_Calibration sketch
scale.tare(); //Assuming there is no weight on the scale at start up, reset the scale to 0

float scaleValue = scale.get_units();

Serial.println("Readings:");
}

void loop() {
Serial.print("Reading: ");
Serial.print(scale.get_units(), 1); //scale.get_units() returns a float
Serial.print(" lbs"); //You can change this to kg but you'll need to refactor the calibration_factor
Serial.println();

if (scale.get_units()>10.0);
{(Serial.println("VDown"));delay (500);}

}

My thought was -- at the end, if the reading is over 10 lbs, then it will send a VDown (volume down) signal. Through python, it will then trigger my computer to decrease volume. I feel okay with the python aspect -- but it's sending a VDown signal to python with every single reading (even of 0lbs)
Any ideas? Am I using the wrong if _ statement?
New to Arduino this week. Apologies to any lengthiness or lack of clarity. Appreciate any comments.

2

Remove the semicolon at the end of this line. That semicolor terminates the if statement.

2 Likes
3

Wow. Thanks. I really appreciate you taking the time to check it over for even such a small thing.. You fixed my project!! (:

4

A quick trick to highlight that error is to use the Tools/auto format:

void setup() {
  // put your setup code here, to run once:
  if (false);
    Serial.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:
}

and with Tools/Auto Format:

void setup() {
  // put your setup code here, to run once:
  if (false)
    ;
  Serial.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:
}
5

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