Hx711.h

00001 #ifndef HX711_h
00002 #define HX711_h
00003 //Translatet module from arduino to mbed https://codebender.cc/library/HX711#HX711.h
00004 
00005 #include "mbed.h"
00006 
00007 class HX711
00008 {
00009     private:
00010         DigitalOut _pin_slk;    // Power Down and Serial Clock Input Pin
00011         DigitalIn _pin_dout;      // Serial Data Output Pin
00012         char GAIN;      // amplification factor
00013         long OFFSET;    // used for tare weight
00014         float SCALE;    // used to return weight in grams, kg, ounces, whatever
00015     public:
00016         // define clock and data pin, channel, and gain factor
00017         // channel selection is made by passing the appropriate gain: 128 or 64 for channel A, 32 for channel B
00018         // gain: 128 or 64 for channel A; channel B works with 32 gain factor only
00019         HX711(PinName pin_dout, PinName pin_slk);
00020 
00021         virtual ~HX711();
00022 
00023         // check if HX711 is ready
00024         // from the datasheet: When output data is not ready for retrieval, digital output pin DOUT is high. Serial clock
00025         // input PD_SCK should be low. When DOUT goes to low, it indicates data is ready for retrieval.
00026 
00027 
00028         // set the gain factor; takes effect only after a call to read()
00029         // channel A can be set for a 128 or 64 gain; channel B has a fixed 32 gain
00030         // depending on the parameter, the channel is also set to either A or B
00031         void set_gain(char gain = 128);
00032 
00033         // waits for the chip to be ready and returns a reading
00034         long read();
00035 
00036         // returns an average reading; times = how many times to read
00037         long read_average(char times = 10);
00038 
00039         // returns (read_average() - OFFSET), that is the current value without the tare weight; times = how many readings to do
00040         double get_value(char times = 1);
00041 
00042         // returns get_value() divided by SCALE, that is the raw value divided by a value obtained via calibration
00043         // times = how many readings to do
00044         float get_units(char times = 1);
00045 
00046         // set the OFFSET value for tare weight; times = how many times to read the tare value
00047         void tare(char times = 10);
00048 
00049         // set the SCALE value; this value is used to convert the raw data to "human readable" data (measure units)
00050         void set_scale(float scale = 1.f);
00051 
00052         // set OFFSET, the value that's subtracted from the actual reading (tare weight)
00053         void set_offset(long offset = 0);
00054 
00055         // puts the chip into power down mode
00056         void power_down();
00057 
00058         // wakes up the chip after power down mode
00059         void power_up();
00060 };
00061 
00062 #endif /* HX711_h */