1.2.7

examples/Calibration/Calibration.ino

@@ -19,7 +19,9 @@
 */
 
 #include <HX711_ADC.h>
+#if defined(ESP8266)|| defined(ESP32) || defined(AVR)
 #include <EEPROM.h>
+#endif
 
 //pins:
 const int HX711_dout = 4; //mcu > HX711 dout pin
@@ -38,7 +40,7 @@ void setup() {
 
   LoadCell.begin();
   unsigned long stabilizingtime = 2000; // preciscion right after power-up can be improved by adding a few seconds of stabilizing time
-  boolean _tare = false; //set this to false if you don't want tare to be performed in the next step
+  boolean _tare = true; //set this to false if you don't want tare to be performed in the next step
   LoadCell.start(stabilizingtime, _tare);
   if (LoadCell.getTareTimeoutFlag() || LoadCell.getSignalTimeoutFlag()) {
     Serial.println("Timeout, check MCU>HX711 wiring and pin designations");

examples/Persistent_zero_offset/Persistent_zero_offset.ino

@@ -0,0 +1,108 @@
+/*
+   -------------------------------------------------------------------------------------
+   HX711_ADC
+   Arduino library for HX711 24-Bit Analog-to-Digital Converter for Weight Scales
+   Olav Kallhovd sept2017
+   -------------------------------------------------------------------------------------
+*/
+
+/*
+   Settling time (number of samples) and data filtering can be adjusted in the config.h file
+   For calibration and storing the calibration value in eeprom, see example file "Calibration.ino"
+
+   The update() function checks for new data and starts the next conversion. In order to acheive maximum effective
+   sample rate, update() should be called at least as often as the HX711 sample rate; >10Hz@10SPS, >80Hz@80SPS.
+   If you have other time consuming code running (i.e. a graphical LCD), consider calling update() from an interrupt routine,
+   see example file "Read_1x_load_cell_interrupt_driven.ino".
+
+   This is an example sketch on how to use this library
+*/
+
+#include <HX711_ADC.h>
+
+#if defined(ESP8266)|| defined(ESP32) || defined(AVR)
+#include <EEPROM.h>
+#endif
+
+//pins:
+const int HX711_dout = 4; //mcu > HX711 dout pin
+const int HX711_sck = 5; //mcu > HX711 sck pin
+
+//HX711 constructor:
+HX711_ADC LoadCell(HX711_dout, HX711_sck);
+
+const int calVal_eepromAdress = 0;
+const int tareOffsetVal_eepromAdress = 4;
+unsigned long t = 0;
+
+void setup() {
+  Serial.begin(57600); delay(10);
+  Serial.println();
+  Serial.println("Starting...");
+
+  LoadCell.begin();
+  float calibrationValue; // calibration value (see example file "Calibration.ino")
+  calibrationValue = 696.0; // uncomment this if you want to set the calibration value in the sketch
+
+#if defined(ESP8266)|| defined(ESP32)
+  EEPROM.begin(512);
+#endif
+
+  //EEPROM.get(calVal_eepromAdress, calibrationValue); // uncomment this if you want to fetch the calibration value from eeprom
+
+  //restore the zero offset value from eeprom:
+  long tare_offset = 0;
+  EEPROM.get(tareOffsetVal_eepromAdress, tare_offset);
+  LoadCell.setTareOffset(tare_offset);
+  boolean _tare = false; //set this to false as the value has been resored from eeprom
+
+  unsigned long stabilizingtime = 2000; // preciscion right after power-up can be improved by adding a few seconds of stabilizing time
+  LoadCell.start(stabilizingtime, _tare);
+  if (LoadCell.getTareTimeoutFlag()) {
+    Serial.println("Timeout, check MCU>HX711 wiring and pin designations");
+    while (1);
+  }
+  else {
+    LoadCell.setCalFactor(calibrationValue); // set calibration value (float)
+    Serial.println("Startup is complete");
+  }
+}
+
+void loop() {
+  static boolean newDataReady = 0;
+  const int serialPrintInterval = 250; //increase value to slow down serial print activity
+
+  // check for new data/start next conversion:
+  if (LoadCell.update()) newDataReady = true;
+
+  // get smoothed value from the dataset:
+  if (newDataReady) {
+    if (millis() > t + serialPrintInterval) {
+      float i = LoadCell.getData();
+      Serial.print("Load_cell output val: ");
+      Serial.println(i);
+      newDataReady = 0;
+      t = millis();
+    }
+  }
+
+  // receive command from serial terminal, send 't' to initiate tare operation:
+  if (Serial.available() > 0) {
+    char inByte = Serial.read();
+    if (inByte == 't') refreshOffsetValueAndSaveToEEprom();
+  }
+}
+
+// zero offset value (tare), calculate and save to EEprom:
+void refreshOffsetValueAndSaveToEEprom() {
+  long _offset = 0;
+  Serial.println("Calculating tare offset value...");
+  LoadCell.tare(); // calculate the new tare / zero offset value (blocking)
+  _offset = LoadCell.getTareOffset(); // get the new tare / zero offset value
+  EEPROM.put(tareOffsetVal_eepromAdress, _offset); // save the new tare / zero offset value to EEprom
+  LoadCell.setTareOffset(_offset); // set value as library parameter (next restart it will be read from EEprom)
+  Serial.print("New tare offset value:");
+  Serial.print(_offset);
+  Serial.print(", saved to EEprom adr:");
+  Serial.println(tareOffsetVal_eepromAdress);
+}

examples/Read_1x_load_cell/Read_1x_load_cell.ino

@@ -19,7 +19,9 @@
 */
 
 #include <HX711_ADC.h>
+#if defined(ESP8266)|| defined(ESP32) || defined(AVR)
 #include <EEPROM.h>
+#endif
 
 //pins:
 const int HX711_dout = 4; //mcu > HX711 dout pin

examples/Read_1x_load_cell_interrupt_driven/Read_1x_load_cell_interrupt_driven.ino

@@ -19,7 +19,9 @@
 */
 
 #include <HX711_ADC.h>
+#if defined(ESP8266)|| defined(ESP32) || defined(AVR)
 #include <EEPROM.h>
+#endif
 
 const int HX711_dout = 3; //mcu > HX711 dout pin, must be external interrupt capable!
 const int HX711_sck = 5; //mcu > HX711 sck pin

examples/Read_2x_load_cell/Read_2x_load_cell.ino

@@ -9,7 +9,9 @@
 // Settling time (number of samples) and data filtering can be adjusted in the config.h file
 
 #include <HX711_ADC.h>
+#if defined(ESP8266)|| defined(ESP32) || defined(AVR)
 #include <EEPROM.h>
+#endif
 
 //pins:
 const int HX711_dout_1 = 4; //mcu > HX711 no 1 dout pin

examples/Testing/Testing.ino

@@ -19,7 +19,9 @@
 */
 
 #include <HX711_ADC.h>
+#if defined(ESP8266)|| defined(ESP32) || defined(AVR)
 #include <EEPROM.h>
+#endif
 
 //pins:
 const int HX711_dout = 6; //mcu > HX711 dout pin

library.properties

@@ -1,5 +1,5 @@
 name=HX711_ADC
-version=1.2.6
+version=1.2.7
 author=Olav Kallhovd
 maintainer=Olav Kallhovd
 sentence=Library for the HX711 24-bit ADC for weight scales.

src/HX711_ADC.cpp

@@ -96,7 +96,7 @@ int HX711_ADC::startMultiple(unsigned long t)
 			}
 			isFirst = 0;
 		}	
-		if(millis() - startMultipleTimeStamp > startMultipleWaitTime) {
+		if((millis() - startMultipleTimeStamp) < startMultipleWaitTime) {
 			update(); //do conversions during stabilization time
 			yield();
 			return 0;
@@ -145,7 +145,7 @@ int HX711_ADC::startMultiple(unsigned long t, bool dotare)
 			}
 			isFirst = 0;
 		}	
-		if(millis() - startMultipleTimeStamp > startMultipleWaitTime) {
+		if((millis() - startMultipleTimeStamp) < startMultipleWaitTime) {
 			update(); //do conversions during stabilization time
 			yield();
 			return 0;