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Topic: HX711_ADC.h (Read 66 times) previous topic - next topic

superdmp

OK, I'm defeated and now ready to ask for help. I feel like I am giving up my man card asking, but three solid days and I feel I'm just missing the simplest of details.

I've been trying to use a load cell with the HX711_ADC.h library. I have not been able to get stabilized output with my own code. I went to the extreme and pulled up the Calibration file, trying to hard-code the calibration weight and every time I change the calibration to a hard-coded known value, the program throws a shit-fit. It works PERFECTLY using the calibration example, but as soon as I try to skip the user input and just assign the value, all hell breaks loose.

If anyone has any ideas, I'm all ears. This is absolutely driving me nuts.

Thank you in advance for any help.

//-------------------------------------------------------------------------------------
// HX711_ADC.h
// Arduino master library for HX711 24-Bit Analog-to-Digital Converter for Weigh Scales
// Olav Kallhovd sept2017
// Tested with      : HX711 asian module on channel A and YZC-133 3kg load cell
// Tested with MCU  : Arduino Nano, ESP8266
//-------------------------------------------------------------------------------------
// This is an example sketch on how to use this library
// Settling time (number of samples) and data filtering can be adjusted in the config.h file

// This example shows how to calibrate the load cell and optionally save the calibration 
// value to EEPROM, and also how to change the value.
// The value can later be fetched from EEPROM in your project sketch.

#include <HX711_ADC.h>
#include <EEPROM.h>

//HX711 constructor (dout pin, sck pin):
HX711_ADC LoadCell(4, 5);

int eepromAdress = 0;

long t;

void calibrate() {
  Serial.println("***");
  Serial.println("Start calibration:");
  Serial.println("It is assumed that the mcu was started with no load applied to the load cell.");
  Serial.println("Now, place your known mass on the loadcell,");
  Serial.println("then send the weight of this mass (i.e. 100.0) from serial monitor.");
  float m = 0;
  boolean f = 0;
  while (f == 0) {
    LoadCell.update();
    if (Serial.available() > 0) {


      m = Serial.parseFloat();     <- this is the line I try to replace with "m=20;" All hell just breaks loose. All of the values returned when I do this, are jumbled and complete garbage.


      if (m != 0) {
        Serial.print("Known mass is: ");
        Serial.println(m);
        f = 1;
      }
      else {
        Serial.println("Invalid value");
      }
    }
  }
  float c = LoadCell.getData() / m;
  LoadCell.setCalFactor(c);
  Serial.print("Calculated calibration value is: ");
  Serial.print(c);
  Serial.println(", use this in your project sketch");
  f = 0;
  Serial.print("Save this value to EEPROM adress ");
  Serial.print(eepromAdress);
  Serial.println("? y/n");
  while (f == 0) {
    if (Serial.available() > 0) {
      char inByte = Serial.read();
      if (inByte == 'y') {
        #if defined(ESP8266)
        EEPROM.begin(512);
        #endif
        EEPROM.put(eepromAdress, c);
        #if defined(ESP8266)
        EEPROM.commit();
        #endif
        EEPROM.get(eepromAdress, c);
        Serial.print("Value ");
        Serial.print(c);
        Serial.print(" saved to EEPROM address: ");
        Serial.println(eepromAdress);
        f = 1;

      }
      else if (inByte == 'n') {
        Serial.println("Value not saved to EEPROM");
        f = 1;
      }
    }
  }
  Serial.println("End calibration");
  Serial.println("For manual edit, send 'c' from serial monitor");
  Serial.println("***");
}

void changeSavedCalFactor() {
  float c = LoadCell.getCalFactor();
  boolean f = 0;
  Serial.println("***");
  Serial.print("Current value is: ");
  Serial.println(c);
  Serial.println("Now, send the new value from serial monitor, i.e. 696.0");
  while (f == 0) {
    if (Serial.available() > 0) {
      c = Serial.parseFloat();
      if (c != 0) {
        Serial.print("New calibration value is: ");
        Serial.println(c);
        LoadCell.setCalFactor(c);
        f = 1;
      }
      else {
        Serial.println("Invalid value, exit");
        return;
      }
    }
  }
  f = 0;
  Serial.print("Save this value to EEPROM adress ");
  Serial.print(eepromAdress);
  Serial.println("? y/n");
  while (f == 0) {
    if (Serial.available() > 0) {
      char inByte = Serial.read();
      if (inByte == 'y') {
        #if defined(ESP8266)
        EEPROM.begin(512);
        #endif
        EEPROM.put(eepromAdress, c);
        #if defined(ESP8266)
        EEPROM.commit();
        #endif
        EEPROM.get(eepromAdress, c);
        Serial.print("Value ");
        Serial.print(c);
        Serial.print(" saved to EEPROM address: ");
        Serial.println(eepromAdress);
        f = 1;
      }
      else if (inByte == 'n') {
        Serial.println("Value not saved to EEPROM");
        f = 1;
      }
    }
  }
  Serial.println("End change calibration value");
  Serial.println("***");
}

void setup() {
  Serial.begin(9600); delay(10);
  Serial.println();
  Serial.println("Starting...");
  LoadCell.begin();
  long stabilisingtime = 2000; // tare preciscion can be improved by adding a few seconds of stabilising time
  LoadCell.start(stabilisingtime);
  if (LoadCell.getTareTimeoutFlag()) {
    Serial.println("Tare timeout, check MCU>HX711 wiring and pin designations");
  }
  else {
    LoadCell.setCalFactor(1.0); // user set calibration value (float)
    Serial.println("Startup + tare is complete");
  }
  while (!LoadCell.update());
  calibrate();
}
void loop() {
  //update() should be called at least as often as HX711 sample rate; >10Hz@10SPS, >80Hz@80SPS
  //longer delay in sketch will reduce effective sample rate (be carefull with delay() in the loop)
  LoadCell.update();

  //get smoothed value from the data set
  if (millis() > t + 250) {
    float i = LoadCell.getData();
    Serial.print("Load_cell output val: ");
    Serial.println(i);
    t = millis();
  }

  //receive from serial terminal
  if (Serial.available() > 0) {
    float i;
    char inByte = Serial.read();
    if (inByte == 't') LoadCell.tareNoDelay();
    else if (inByte == 'c') changeSavedCalFactor();
  }

  //check if last tare operation is complete
  if (LoadCell.getTareStatus() == true) {
    Serial.println("Tare complete");
  }

}

pert

every time I change the calibration to a hard-coded known value, the program throws a [EXPLETIVE DELETED]-fit. It works PERFECTLY using the calibration example, but as soon as I try to skip the user input and just assign the value, all hell breaks loose.
Please provide a detailed description of the problem you encounter when you do that.

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