Noobe simple syntax questions

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1

Serial.print("one reading:\t");
Serial.print(scale.get_units(), 1);
Serial.print("\t| average:\t");
Serial.println(scale.get_units(10), 1);

This is one section of a digital scale program for use with the H7111 ADC/instrumentation amplifier.
My question is about the 2nd and 4th line ...the Serial.print(scale.get_units(), );
How am I supposed to know that scale.get_units grabs the current count of the ADC? At no point in this program is scale.get_units defined as either a variable or command.In the comments after each line it says that this line is supposed to print the average of 10 readings from the ADC, WHAT IS THE ''1' FOR ALSO.
HERE is the entire program
#include "HX711.h"

// HX711.DOUT - pin #A1
// HX711.PD_SCK - pin #A0

HX711 scale(A1, A0); // parameter "gain" is ommited; the default value 128 is used by the library

void setup() {
Serial.begin(38400);
Serial.println("HX711 Demo");

Serial.println("Before setting up the scale:");
Serial.print("read: \t\t");
Serial.println(scale.read()); // print a raw reading from the ADC

Serial.print("read average: \t\t");
Serial.println(scale.read_average(20)); // print the average of 20 readings from the ADC

Serial.print("get value: \t\t");
Serial.println(scale.get_value(5)); // print the average of 5 readings from the ADC minus the tare weight (not set yet)

Serial.print("get units: \t\t");
Serial.println(scale.get_units(5), 1); // print the average of 5 readings from the ADC minus tare weight (not set) divided
// by the SCALE parameter (not set yet)

scale.set_scale(2280.f); // this value is obtained by calibrating the scale with known weights; see the README for details
scale.tare(); // reset the scale to 0

Serial.println("After setting up the scale:");

Serial.print("read: \t\t");
Serial.println(scale.read()); // print a raw reading from the ADC

Serial.print("read average: \t\t");
Serial.println(scale.read_average(20)); // print the average of 20 readings from the ADC

Serial.print("get value: \t\t");
Serial.println(scale.get_value(5)); // print the average of 5 readings from the ADC minus the tare weight, set with tare()

Serial.print("get units: \t\t");
Serial.println(scale.get_units(5), 1); // print the average of 5 readings from the ADC minus tare weight, divided
// by the SCALE parameter set with set_scale

Serial.println("Readings:");
}

void loop() {
Serial.print("one reading:\t");
Serial.print(scale.get_units(), 1);
Serial.print("\t| average:\t");
Serial.println(scale.get_units(10), 1);

scale.power_down(); // put the ADC in sleep mode
delay(5000);
scale.power_up();
}
I have built this circuit using 1 load cell and everything works fine , I am getting proportional readings from the serial monitor, however I would like to convert these unknown units into pounds and I have worked out that approx. 7.5 units from the ADC is equivalent to 1 pound but I am having difficulty finding the right place in the program to insert this conversion because I am expecting to see variables initialized and named but I do not see anything remotely like that in this program..in fact that is my biggest hangup with this program is that their are no varibles, why?

4

beatlessteve:
How am I supposed to know that scale.get_units grabs the current count of the ADC? At no point in this program is scale.get_units defined as either a variable or command.In the comments after each line it says that this line is supposed to print the average of 10 readings from the ADC,

The 'scale' object is declared as type "HX711". That class is likely declared in the HX711.h file. The HX711 library should have come with documentation or examples.

beatlessteve:
WHAT IS THE ''1' FOR ALSO.

If the function returns a 'float' it means "display with 1 decimal place" (the default is 2). If the function returns an integer the '1' means nothing. There are some defined constants DEC=10 (decimal), HEX=16 (hexadecimal), OCT=8 (octal), and BIN=2 (binary) which select the display format for integers. The default is DEC.

beatlessteve:
my biggest hangup with this program is that their are no variables, why?

Because they are not needed. From your output you can see which function calls return which data. If it's a simple matter of scaling you can just add that to the expression:

const float CountsPerPound = 7.5;
  Serial.print("one reading:\t");
  Serial.print(scale.get_units() / CountsPerPound, 1);
  Serial.print("\t| average:\t");
  Serial.println(scale.get_units(10) / CountsPerPound, 1);
5

beatlessteve:
How am I supposed to know that scale.get_units grabs the current count of the ADC? At no point in this program is scale.get_units defined as either a variable or command.

Ok. So you need to learn about classes and class methods.

Read this: http://www.cplusplus.com/doc/tutorial/classes/.