0.3.0 HX711

2024-10-03 18:09:02 -04:00 · 2021-11-16 17:42:29 +01:00 · 2021-11-16 17:42:29 +01:00 · b59bfcd56f
commit b59bfcd56f
parent 36c3e468a0
18 changed files with 281 additions and 73 deletions
--- a/libraries/HX711/.arduino-ci.yml
+++ b/libraries/HX711/.arduino-ci.yml
@ -2,6 +2,10 @@ compile:
  # Choosing to run compilation tests on 2 different Arduino platforms
  platforms:
    - uno
-    - leonardo
-    - due
-    - zero
+    # - due
+    # - zero
+    # - leonardo
+    - m4
+    - esp32
+    # - esp8266
+    # - mega2560
--- a/libraries/HX711/.github/workflows/arduino_test_runner.yml
+++ b/libraries/HX711/.github/workflows/arduino_test_runner.yml
@ -4,11 +4,14 @@ name: Arduino CI
 on: [push, pull_request]

 jobs:
-  arduino_ci:
+  runTest:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v2
-      # - uses: Arduino-CI/action@latest
-      - uses: Arduino-CI/action@master
-          #   Arduino-CI/action@v0.1.1
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.6
+      - run: |
+          gem install arduino_ci
+          arduino_ci.rb
--- a/libraries/HX711/HX711.cpp
+++ b/libraries/HX711/HX711.cpp
@ -1,7 +1,7 @@
 //
 //    FILE: HX711.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.2.3
+// VERSION: 0.3.0
 // PURPOSE: Library for Loadcells for UNO
 //     URL: https://github.com/RobTillaart/HX711
 //
@ -12,6 +12,9 @@
 //  0.2.1   2020-12-28  add arduino-ci + unit test
 //  0.2.2   2021-05-10  add read_median(), fix typo, add mode operandi
 //  0.2.3   2021-05-26  add running_average() mode
+//  0.3.0   2021-11-14  fix #11 shiftIn timing
+//                      update build-CI, readme.md, badges
+


 #include "HX711.h"
@ -28,7 +31,7 @@ HX711::~HX711() {}

 void HX711::begin(uint8_t dataPin, uint8_t clockPin)
 {
-  _dataPin = dataPin;
+  _dataPin  = dataPin;
  _clockPin = clockPin;

  pinMode(_dataPin, INPUT);
@ -55,6 +58,11 @@ bool HX711::is_ready()
 }


+//  from datasheet page 4
+//  When output data is not ready for retrieval,
+//  digital output pin DOUT is high. Serial clock
+//  input PD_SCK should be low. When DOUT goes
+//  to low, it indicates data is ready for retrieval.
 float HX711::read() 
 {
  // this waiting takes most time...
@ -69,9 +77,12 @@ float HX711::read()
  noInterrupts();

  // Pulse the clock pin 24 times to read the data.
-  v.data[2] = shiftIn(_dataPin, _clockPin, MSBFIRST);
-  v.data[1] = shiftIn(_dataPin, _clockPin, MSBFIRST);
-  v.data[0] = shiftIn(_dataPin, _clockPin, MSBFIRST);
+  // v.data[2] = shiftIn(_dataPin, _clockPin, MSBFIRST);
+  // v.data[1] = shiftIn(_dataPin, _clockPin, MSBFIRST);
+  // v.data[0] = shiftIn(_dataPin, _clockPin, MSBFIRST);
+  v.data[2] = _shiftIn();
+  v.data[1] = _shiftIn();
+  v.data[0] = _shiftIn();

  // TABLE 3 page 4 datasheet
  // only default verified, so other values not supported yet
@ -271,4 +282,27 @@ void HX711::power_up()
  digitalWrite(_clockPin, LOW);
 }

+
+//  MSB_FIRST optimized shiftIn
+//  see datasheet page 5 for timing
+uint8_t HX711::_shiftIn()
+{
+  uint8_t value = 0;
+  uint8_t mask = 0x80;
+  while(mask > 0)
+  {
+    digitalWrite(_clockPin, HIGH);
+    delayMicroseconds(1);               // T2  >= 0.2 us
+    if (digitalRead(_dataPin) == HIGH)
+    {
+      value |= mask;
+    }
+    digitalWrite(_clockPin, LOW);
+    delayMicroseconds(1);               // keep duty cycle ~50%
+    mask >>= 1;
+  }
+  return value;
+}
+
+
 // -- END OF FILE --
--- a/libraries/HX711/HX711.h
+++ b/libraries/HX711/HX711.h
@ -2,7 +2,7 @@
 //
 //    FILE: HX711.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.2.3
+// VERSION: 0.3.0
 // PURPOSE: Library for Loadcells for UNO
 //     URL: https://github.com/RobTillaart/HX711
 //
@ -15,7 +15,7 @@

 #include "Arduino.h"

-#define HX711_LIB_VERSION  (F("0.2.3"))
+#define HX711_LIB_VERSION               (F("0.3.0"))


 const uint8_t HX711_AVERAGE_MODE = 0x00;
@ -39,7 +39,7 @@ public:

  void     reset();

-  // checks if loadcell is ready to read.
+  // checks if load cell is ready to read.
  bool     is_ready();
  
  // wait until ready, 
@ -142,6 +142,7 @@ private:
  uint8_t  _mode     = 0;

  void     _insertSort(float * array, uint8_t size);
+  uint8_t  _shiftIn();
 };

 // -- END OF FILE --
--- a/libraries/HX711/README.md
+++ b/libraries/HX711/README.md
@ -1,22 +1,39 @@

 [![Arduino CI](https://github.com/RobTillaart/HX711/workflows/Arduino%20CI/badge.svg)](https://github.com/marketplace/actions/arduino_ci)
+[![Arduino-lint](https://github.com/RobTillaart/HX711/actions/workflows/arduino-lint.yml/badge.svg)](https://github.com/RobTillaart/HX711/actions/workflows/arduino-lint.yml)
+[![JSON check](https://github.com/RobTillaart/HX711/actions/workflows/jsoncheck.yml/badge.svg)](https://github.com/RobTillaart/HX711/actions/workflows/jsoncheck.yml)
 [![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/RobTillaart/HX711/blob/master/LICENSE)
 [![GitHub release](https://img.shields.io/github/release/RobTillaart/HX711.svg?maxAge=3600)](https://github.com/RobTillaart/HX711/releases)


 # HX711

-Arduino library for HX711 24 bit ADC  used for load cells and scales.
+Arduino library for HX711 24 bit ADC used for load cells and scales.


 ## Description

-This HX711 library has an interface which is a superset of a library made by bogde.
+This HX711 library has an interface which is a superset of a library made by Bogde.
 Some missing functions were added to get more info from the lib. 

-Another important difference is that this library uses floats. The 23 bits mantisse 
-of the IEE754 float matches the 24 bit ADC very well. Furthermore it gave a smaller
-footprint.
+Another important difference is that this library uses floats. 
+The 23 bits mantissa of the IEE754 float matches the 24 bit ADC very well. 
+Furthermore it gave a smaller footprint.
+
+
+### Breaking change 0.3.0
+
+In issue #11 it became clear that the timing of the default **shiftIn()** function that
+reads the value of the internal ADC was too fast on some processor boards for the HX711.
+This resulted in missing the first = sign bit and value read could be a factor two
+higher than should. If one calibrated the sensor this would be compensated with the 
+factor that is derived in the calibration process. 
+
+In 0.3.0 a dedicated **shiftIn()** function is added into this library that uses hard
+coded delays to keep the timing of the clock within datasheet parameters. 
+This should guarantee that the sign bit is read correctly on all platforms. 
+Drawback is that reading the HX711 takes an ~50 extra microseconds.
+How much this affects performance is to be investigated.


 ## Main flow
@ -37,26 +54,105 @@ Steps to take for calibration
 1. save the offset and scale for later use e.g. EEPROM.


-## Pricing
+## Interface
+
+
+#### Base
+
+- **HX711()** constructor.
+- **~HX711()**
+- **void begin(uint8_t dataPin, uint8_t clockPin)** sets a fixed gain 128 for now.
+- **void reset()** set internal state to start condition.
+- **bool is_ready()** checks if load cell is ready to read.
+- **void wait_ready(uint32_t ms = 0)** wait until ready, check every ms.
+- **bool wait_ready_retry(uint8_t retries = 3, uint32_t ms = 0)** wait max retries.
+- **bool wait_ready_timeout(uint32_t timeout = 1000, uint32_t ms = 0)** wait max timeout.
+- **float read()** raw read.
+- **float read_average(uint8_t times = 10)** get average of times raw reads. times = 1 or more.
+- **float read_median(uint8_t times = 7)** get median of multiple raw reads. 
+times = 3..15 - odd numbers preferred.
+- **float read_medavg(uint8_t times = 7)** get average of "middle half" of multiple raw reads.
+times = 3..15 - odd numbers preferred.
+- **float read_runavg(uint8_t times = 7, float alpha = 0.5)** get running average over times measurements.
+The weight alpha can be set to any value between 0 and 1, times >= 1.
+- **uint32_t last_read()** returns timestamp in milliseconds.
+
+
+#### Gain
+
+read datasheet - see also Connections HX711 below
+
+- **void set_gain(uint8_t gain = 128)** values: 128 (default), 64 32  - only 128 tested & verified.
+- **uint8_t get_gain()** returns set gain.
+
+
+#### Mode 
+
+Get and set the operational mode for get_value() and indirect get_units().
+In median and medavg mode only 3..15 samples are allowed.
+- **void set_average_mode()**
+- **void set_median_mode()**
+- **void set_medavg_mode()**
+- **void set_runavg_mode()** default alpha = 0.5.
+- **uint8_t get_mode()**
+
+
+#### Get values
+
+get values corrected for offset and scale
+
+- **float get_value(uint8_t times = 1)** read value, corrected for offset.
+- **float get_units(uint8_t times = 1)** read value, converted to proper units.
+- **void set_scale(float scale = 1.0)** set scale factor; scale > 0.
+- **float get_scale()** returns set scale factor.
+- **void set_offset(long offset = 0)** idem.
+- **long get_offset()** idem.
+
+
+#### Tare & calibration
+
+Steps to take for calibration
+1. clear the scale
+1. call tare() to set the zero offset
+1. put a known weight on the scale 
+1. call calibrate_scale(weight) 
+1. scale is calculated.
+1. save the offset and scale for later use e.g. EEPROM.
+
+- **void tare(uint8_t times = 10)** call tare to calibrate zero level
+- **float get_tare()** idem.
+- **bool tare_set()** checks if a tare has been set.
+- **void calibrate_scale(uint16_t weight, uint8_t times = 10)** idem.
+
+
+#### Power management
+
+- **void power_down()** idem.
+- **void power_up()** idem.
+
+
+#### Pricing

 Some price functions were added to make it easy to use this library
-for pricing goods or for educational purposes. These functions are under discussion
-if they will stay. Another set of function to add weights together didn't make it in 
-the 0.2.0 release, it is on a todo list.
-
+for pricing goods or for educational purposes. 
+These functions are under discussion if they will stay.
 For weight conversion functions see https://github.com/RobTillaart/weight

+- **float get_price(uint8_t times = 1)** idem.
+- **void  set_unit_price(float price = 1.0)** idem.
+- **float get_unit_price()** idem.
+

 ## Notes


-### Scale values for loadcells
+### Scale values for load cells

-These scale values worked pretty well with a set of loadcells, 
-Use calibrate to find your values.
+These scale values worked pretty well with a set of load cells I have, 
+Use calibrate to find your favourite values.

- 5 KG loadcell   scale.set_scale(420.52); 
- 20 KG loadcell  scale.set_scale(127.15); 
+- 5 KG load cell   scale.set_scale(420.52);
+- 20 KG load cell  scale.set_scale(127.15);


 ### Connections HX711
@ -67,31 +163,32 @@ Use calibrate to find your values.

 ### Connections

-| HX711 Pin | Color |
-|:----:|:----:|
-|  E+  |  red           |
-|  E-  |  black         |
-|  A-  |  white         |
-|  A+  |  green         |
-|  B-  |  not connected |
-|  B+  |  not connected |
+| HX711 Pin |  Colour        |
+|:---------:|:--------------:|
+|    E+     |  red           |
+|    E-     |  black         |
+|    A-     |  white         |
+|    A+     |  green         |
+|    B-     |  not connected |
+|    B+     |  not connected |


-| HX711 Pin | Color |
-|:----:|:----:|
-|  E+  | red           |
-|  E-  | black         |
-|  A-  | blue          |
-|  A+  | white         |
-|  B-  | not connected |
-|  B+  | not connected |
+| HX711 Pin |  Colour        |
+|:---------:|:--------------:|
+|    E+     |  red           |
+|    E-     |  black         |
+|    A-     |  blue          |
+|    A+     |  white         |
+|    B-     |  not connected |
+|    B+     |  not connected |


 ### Temperature

-Loadcells do have a temperature related error.
+
+Load cells do have a temperature related error. (check datasheet)
 This can be reduced by doing the calibration and take the tare 
-at the temperature one also does the measurements.
+at the temperature one also uses for the measurements.

 Another way to handle this is to add a good temperature sensor
 (e.g. DS18B20, SHT85) and compensate for the temperature
@ -101,3 +198,17 @@ differences in your code.
 ## Operation

 See examples
+
+
+## Future
+
+- update documentation
+- add examples
+- test different load cells
+- optimize the build-in **ShiftIn()** function to improve performance again.
+
+
+#### the adding scale
+
+- void weight_clr(), void weight_add(), float weight_get() - adding scale 
+
--- a/libraries/HX711/examples/HX_delta_scale/HX_delta_scale.ino
+++ b/libraries/HX711/examples/HX_delta_scale/HX_delta_scale.ino
@ -9,6 +9,7 @@
 // 0.1.0    2020-06-16 initial version
 //

+
 // to be tested 

 #include "HX711.h"
@ -20,6 +21,7 @@ uint8_t clockPin = 7;

 float w1, w2, previous = 0;

+
 void setup()
 {
  Serial.begin(115200);
@ -33,16 +35,17 @@ void setup()
  Serial.print("UNITS: ");
  Serial.println(scale.get_units(10));

-  // loadcell factor 20 KG
+  // load cell factor 20 KG
  // scale.set_scale(127.15);
-  // loadcell factor 5 KG
-  scale.set_scale(420.0983);
+  // load cell factor 5 KG
+  scale.set_scale(420.0983);       // TODO you need to calibrate this yourself.
  scale.tare();

  Serial.print("UNITS: ");
  Serial.println(scale.get_units(10));
 }

+
 void loop()
 {
  // read until stable
@ -71,4 +74,6 @@ void loop()
  delay(100);
 }

-// END OF FILE
+
+// -- END OF FILE --
+
--- a/libraries/HX711/examples/HX_grocery_scale/HX_grocery_scale.ino
+++ b/libraries/HX711/examples/HX_grocery_scale/HX_grocery_scale.ino
@ -9,6 +9,7 @@
 // 0.1.0    2020-06-16 initial version
 //

+
 #include "HX711.h"

 HX711 scale;
@ -54,6 +55,7 @@ void setup()
  scale.set_unit_price(0.031415);  // we only have one price
 }

+
 void loop()
 {
  Serial.print("UNITS: ");
@ -63,4 +65,6 @@ void loop()
  delay(250);
 }

-// END OF FILE
+
+// -- END OF FILE --
+
--- a/libraries/HX711/examples/HX_kitchen_scale/HX_kitchen_scale.ino
+++ b/libraries/HX711/examples/HX_kitchen_scale/HX_kitchen_scale.ino
@ -9,6 +9,7 @@
 // 0.1.0    2020-06-16 initial version
 //

+
 #include "HX711.h"

 HX711 scale;
@ -48,11 +49,13 @@ void setup()
  Serial.println(scale.get_units(10));

  Serial.println("\nScale is calibrated, press a key to continue");
+  // Serial.println(scale.get_scale());
+  // Serial.println(scale.get_offset());
  while(!Serial.available());
  while(Serial.available()) Serial.read();
-
 }

+
 void loop()
 {
  Serial.print("UNITS: ");
@ -60,4 +63,6 @@ void loop()
  delay(250);
 }

-// END OF FILE
+
+// -- END OF FILE --
+
--- a/libraries/HX711/examples/HX_performance/HX_performance.ino
+++ b/libraries/HX711/examples/HX_performance/HX_performance.ino
@ -9,6 +9,7 @@
 // 0.1.0    2020-06-15 initial version
 //

+
 #include "HX711.h"

 HX711 scale;
@ -19,6 +20,7 @@ uint8_t clockPin = 7;
 uint32_t start, stop;
 volatile float f;

+
 void setup()
 {
  Serial.begin(115200);
@ -34,11 +36,11 @@ void setup()
  measure(10);

  // TODO find a nice solution for this calibration..
-  // loadcell factor 20 KG
+  // load cell factor 20 KG
  // scale.set_scale(127.15);

-  // loadcell factor 5 KG
-  scale.set_scale(420.0983);
+  // load cell factor 5 KG
+  scale.set_scale(420.0983);       // TODO you need to calibrate this yourself.
  // reset the scale to zero = 0
  scale.tare();

@ -54,6 +56,11 @@ void setup()
  delay(1000);
  measure(10);

+/*
+ * PERFORMANCE
+ * 100x get_units(1) = 9404352  (UNO)
+ * VAL: 0.05
+ */
  Serial.println("\nPERFORMANCE");
  start = micros();
  f = 0;
@ -75,9 +82,9 @@ void setup()
  }
  Serial.print("  VAL:");
  Serial.println(f * 0.01, 4);
-
 }

+
 void loop()
 {
  // continuous scale 4x per second
@ -86,6 +93,7 @@ void loop()
  delay(250);
 }

+
 void measure(uint8_t cnt)
 {
  Serial.print("  RAW: ");
@ -100,3 +108,4 @@ void measure(uint8_t cnt)


 // -- END OF FILE --
+
--- a/libraries/HX711/examples/HX_performance2/HX_performance2.ino
+++ b/libraries/HX711/examples/HX_performance2/HX_performance2.ino
@ -9,6 +9,7 @@
 // 0.1.0    2020-06-15 initial version
 //

+
 #include "HX711.h"

 HX711 scale;
@ -19,6 +20,7 @@ uint8_t clockPin = 7;
 uint32_t start, stop;
 volatile float f;

+
 void setup()
 {
  Serial.begin(115200);
@ -30,21 +32,23 @@ void setup()
  scale.begin(dataPin, clockPin);

  // TODO find a nice solution for this calibration..
-  // loadcell factor 20 KG
+  // load cell factor 20 KG
  // scale.set_scale(127.15);

-  // loadcell factor 5 KG
-  scale.set_scale(420.0983);
+  // load cell factor 5 KG
+  scale.set_scale(420.0983);       // TODO you need to calibrate this yourself.
  // reset the scale to zero = 0
  scale.tare();

  measure();
 }

+
 void loop()
 {
 }

+
 void measure()
 {
  Serial.println("Counting get_units() calls for 1 minute...");
@ -66,3 +70,4 @@ void measure()


 // -- END OF FILE --
+
--- a/libraries/HX711/examples/HX_plotter/HX_plotter.ino
+++ b/libraries/HX711/examples/HX_plotter/HX_plotter.ino
@ -9,6 +9,7 @@
 // 0.1.0    2020-06-15 initial version
 //

+
 #include "HX711.h"

 HX711 scale;
@ -19,6 +20,7 @@ uint8_t clockPin = 7;
 uint32_t start, stop;
 volatile float f;

+
 void setup()
 {
  Serial.begin(115200);
@ -30,14 +32,15 @@ void setup()
  scale.begin(dataPin, clockPin);

  // TODO find a nice solution for this calibration..
-  // loadcell factor 20 KG
+  // load cell factor 20 KG
  // scale.set_scale(127.15);
-  // loadcell factor 5 KG
-  scale.set_scale(420.0983);
+  // load cell factor 5 KG
+  scale.set_scale(420.0983);       // TODO you need to calibrate this yourself.
  // reset the scale to zero = 0
  scale.tare();
 }

+
 void loop()
 {
  // continuous scale 4x per second
@ -46,4 +49,6 @@ void loop()
  delay(250);
 }

+
 // -- END OF FILE --
+
--- a/libraries/HX711/examples/HX_read_median/HX_read_median.ino
+++ b/libraries/HX711/examples/HX_read_median/HX_read_median.ino
@ -9,6 +9,7 @@
 // 0.1.0    2021-05-10 initial version
 //

+
 #include "HX711.h"

 HX711 scale;
@ -19,6 +20,7 @@ uint8_t clockPin = 7;
 uint32_t start, stop;
 volatile float f;

+
 void setup()
 {
  Serial.begin(115200);
@ -30,10 +32,10 @@ void setup()
  scale.begin(dataPin, clockPin);

  // TODO find a nice solution for this calibration..
-  // loadcell factor 20 KG
-  scale.set_scale(127.15);
+  // load cell factor 20 KG
+  scale.set_scale(127.15);       // TODO you need to calibrate this yourself.

-  // loadcell factor 5 KG
+  // load cell factor 5 KG
  // scale.set_scale(420.0983);
  // reset the scale to zero = 0
  scale.tare();
@ -52,6 +54,7 @@ void setup()
  Serial.println(f, 2);
 }

+
 void loop()
 {
  // continuous scale once per second
@ -62,3 +65,4 @@ void loop()


 // -- END OF FILE --
+
--- a/libraries/HX711/examples/HX_read_median_average/HX_read_median_average.ino
+++ b/libraries/HX711/examples/HX_read_median_average/HX_read_median_average.ino
@ -9,6 +9,7 @@
 // 0.1.0    2021-05-13 initial version
 //

+
 #include "HX711.h"

 HX711 scale;
@ -19,6 +20,7 @@ uint8_t clockPin = 7;
 uint32_t start, stop;
 volatile float f;

+
 void setup()
 {
  Serial.begin(115200);
@ -52,6 +54,7 @@ void setup()
  Serial.println(f, 2);
 }

+
 void loop()
 {
  // continuous scale once per second
@ -60,4 +63,6 @@ void loop()
  delay(1000);
 }

+
 // -- END OF FILE --
+
--- a/libraries/HX711/examples/HX_set_mode/HX_set_mode.ino
+++ b/libraries/HX711/examples/HX_set_mode/HX_set_mode.ino
@ -9,6 +9,7 @@
 // 0.1.0    2021-05-13 initial version
 //

+
 #include "HX711.h"

 HX711 scale;
@ -19,6 +20,7 @@ uint8_t clockPin = 7;
 uint32_t start, stop;
 volatile float f;

+
 void setup()
 {
  Serial.begin(115200);
@ -91,8 +93,11 @@ void setup()
  Serial.println("\ndone...");
 }

+
 void loop()
 {
 }

+
 // -- END OF FILE --
+
--- a/libraries/HX711/keywords.txt
+++ b/libraries/HX711/keywords.txt
@ -1,8 +1,9 @@
-# Syntax Coloring Map For HX711
+# Syntax Colouring Map For HX711

-# Datatypes (KEYWORD1)
+# Data types (KEYWORD1)
 HX711	KEYWORD1

+
 # Methods and Functions (KEYWORD2)
 begin	KEYWORD2
 reset	KEYWORD2
@ -16,6 +17,7 @@ read	KEYWORD2
 read_average	KEYWORD2
 read_median	KEYWORD2
 read_medavg	KEYWORD2
+read_runavg	KEYWORD2

 set_average_mode	KEYWORD2
 set_median_mode	KEYWORD2
@ -49,8 +51,13 @@ get_price	KEYWORD2
 set_unit_price	KEYWORD2
 get_unit_price	KEYWORD2

+
 # Instances (KEYWORD2)

+
 # Constants (LITERAL1)
 HX711_LIB_VERSION	LITERAL1
-
+HX711_AVERAGE_MODE	LITERAL1
+HX711_MEDIAN_MODE	LITERAL1
+HX711_MEDAVG_MODE	LITERAL1
+HX711_RUNAVG_MODE	LITERAL1
--- a/libraries/HX711/library.json
+++ b/libraries/HX711/library.json
@ -15,7 +15,7 @@
    "type": "git",
    "url": "https://github.com/RobTillaart/HX711"
  },
-  "version": "0.2.3",
+  "version": "0.3.0",
  "license": "MIT",
  "frameworks": "arduino",
  "platforms": "*"
--- a/libraries/HX711/library.properties
+++ b/libraries/HX711/library.properties
@ -1,5 +1,5 @@
 name=HX711
-version=0.2.3
+version=0.3.0
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino library for HX711 loadcell amplifier
--- a/libraries/HX711/test/unit_test_001.cpp
+++ b/libraries/HX711/test/unit_test_001.cpp
@ -53,6 +53,7 @@ unittest(test_constructor)
  assertEqual(0, scale.last_read());
 }

+
 unittest(test_gain)
 {
  HX711 scale;