HX711 Class
Here we can find the documentation for the HX711 library
HX711 public functions
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HX711()
Construct a new HX711 object.
Note
The constructer can be used without any parameter. If no parameter is given it will use the standart pins set by
menuconfig.
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HX711(hx711_conf_t *conf_hx711)
Construct a new HX711 object with config.
If you want to setup the hx711 from programm you can use this function.
- Parameters:
conf_hx711 – Config struct for hx711 modul. See hx711_conf_t.
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inline ~HX711()
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float getOffset()
Get the the offset of the hx711 modul.
- Returns:
Return the offset value.
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float getScale()
Get the scale factor value.
- Returns:
Return the scale factor
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void poweron()
Function to power on the hx711 controller.
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void setGain(hx711_gain gain)
Set the gain for hx711.
Here you can set the gain. There are 3 option aviable. See hx711_gain for more information.
- Parameters:
gain – Set the gain
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void setOffset(float newoffset)
Set the offset for hx711 modul.
- Parameters:
newoffset – Offset value
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void setScale(float scaleFactor)
Function to set the scale factor.
This factor will be used to get right value based on which load cell is connected to the hx711
- Parameters:
scaleFactor – Set the scale factor
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void standby()
Function to bring the hx711 to standby mode.
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void startTask()
Start background task.
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void stopTask()
Stop background task.
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void tare()
Function to tare the cell load.
In this function we will read the sensor for the number TARESAMPLES to get the offset. In the start of the function we will also read the load until 2 seconds to get a more accurate result.
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void update()
Function to manuel trigger value read.
This function can be used to trigger the read. It will be used when no background task running. This function will trigger ::wait_ready.
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bool wait_ready(unsigned long delay_ms = 1)
Function to wait until hx711 is ready for shift out data.
It will wait until PDOUT went LOW or it will be more the 10 trys. In this case ::_error will get true and it will stop to read value. In the case ::_error will get true maybe there is a problem with your wiring.
Note
Note we read the value for 10 times to get an average to have a more accurate result. When the hx711 modul is set to 10Mhz we get all second one result 10MHz/10. After some testing it resuslts that it looks like the modul i testet has about 5Mhz. So we get a result every 2 seconds.
- Parameters:
delay_ms – Time wait between next call
- Returns:
true
- Returns:
false
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float cellload
HX711 private functions
Note
Only show for complete the documentation
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void init()
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void _readData()
Function to shift out the value from hx711 modul.
Note
In this function we disable all interrupts to for shifting
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float read_average(uint8_t times)
Helper function to get the average of load.
This function will always be called when we read the value. It will take samples of
ntimes to get a more accurate result. It will also remove the highest and lowest value.- Parameters:
times – number of reading value
- Returns:
float return the average sum of readings
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uint8_t trys
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gpio_num_t _pdsck
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gpio_num_t _dout
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int _gain
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float _oload
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float _scale
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uint8_t raw_data[3]
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gpio_config_t pdsck_conf
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gpio_config_t dout_conf
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float offset
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int read_times
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bool _error
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float _loadsamples[TARESAMPLES]
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bool taskrun
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static void hx711Task(void *pvParameter)
Background Task for reading out hx711 value.
HX711 gain enum
Definition of the gain for hx711
HX711 config struct
Struct used to set the config for hx711 library
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struct hx711_conf_t
Struct for configuration.
HX711 defines
Here you can see the defaults defines
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SCALE 491.f
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OFFSET 46709.0
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TARESAMPLES 20
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WAIT_TIME 20