Read Arduino Hardware specifications in C++ - arduino

Question

I recently started into C++ and Arduino Coding which makes a lot of fun! I have different boards for example an Arduino UNO R3, Arduino Mini and an Arduino compatible Teensy 3.2.
I'd like to make my program to automatically select specific pins. Over the EEPROM library (not sure if library is the right term, as I said im new to c++) I can get the EEPROM size of each board. Is there any way to get other datas as how many digital/analgs pins the board has which can be used as Input and Output pins?

Answer 1

The number of digital pins is defined in the NUM_DIGITAL_PINS macro.
The number of analog input pins is defined in the NUM_ANALOG_INPUTS macro.
The macros are located at(added by request of OP):
Uno: https://github.com/arduino/Arduino/blob/1.6.12/hardware/arduino/avr/variants/standard/pins_arduino.h#L28-L29
#define NUM_DIGITAL_PINS 20
#define NUM_ANALOG_INPUTS 6
Mini: https://github.com/arduino/Arduino/blob/1.6.12/hardware/arduino/avr/variants/standard/pins_arduino.h#L28
#define NUM_DIGITAL_PINS 20
and
https://github.com/arduino/Arduino/blob/1.6.12/hardware/arduino/avr/variants/eightanaloginputs/pins_arduino.h#L25
#include "../standard/pins_arduino.h"
#undef NUM_ANALOG_INPUTS
#define NUM_ANALOG_INPUTS 8
Teensy 3.x:
https://github.com/PaulStoffregen/cores/blob/1.31/teensy3/core_pins.h#L97-L127
#if defined(__MK20DX128__)
#define CORE_NUM_TOTAL_PINS 34
#define CORE_NUM_DIGITAL 34
#define CORE_NUM_INTERRUPT 34
#define CORE_NUM_ANALOG 14
#define CORE_NUM_PWM 10
#elif defined(__MK20DX256__)
#define CORE_NUM_TOTAL_PINS 34
#define CORE_NUM_DIGITAL 34
#define CORE_NUM_INTERRUPT 34
#define CORE_NUM_ANALOG 21
#define CORE_NUM_PWM 12
#elif defined(__MKL26Z64__)
#define CORE_NUM_TOTAL_PINS 27
#define CORE_NUM_DIGITAL 27
#define CORE_NUM_INTERRUPT 24 // really only 18, but 6 "holes"
#define CORE_NUM_ANALOG 13
#define CORE_NUM_PWM 10
#elif defined(__MK64FX512__)
#define CORE_NUM_TOTAL_PINS 64
#define CORE_NUM_DIGITAL 64
#define CORE_NUM_INTERRUPT 64
#define CORE_NUM_ANALOG 27
#define CORE_NUM_PWM 20
#elif defined(__MK66FX1M0__)
#define CORE_NUM_TOTAL_PINS 64
#define CORE_NUM_DIGITAL 64
#define CORE_NUM_INTERRUPT 64
#define CORE_NUM_ANALOG 25
#define CORE_NUM_PWM 22
#endif
and
https://github.com/PaulStoffregen/cores/blob/1.31/teensy3/pins_arduino.h#L157-L158
#define NUM_DIGITAL_PINS CORE_NUM_DIGITAL
#define NUM_ANALOG_INPUTS CORE_NUM_ANALOG
The will be found in similar locations for other boards. You just need to check the build.variant value set in boards.txt for that board and then go to the folder of the same name under the variants folder of the board's platform.
You might find some other useful things by looking through those variant files.