Is NUM_TOTAL_PINS correct? #6
Description
in variant/uno2018/pins_arduino.h there is:
#define NUM_DIGITAL_PINS 20
#define NUM_ANALOG_INPUTS 6
:
#define NUM_TOTAL_PINS (NUM_DIGITAL_PINS + NUM_ANALOG_INPUTS + NUM_TESTPOINT_PINS + NUM_OCCUPIED_PINS)
But the DIGITAL_PINS and ANALOG_INPUTS overlap, right? Pin14 an Ain0 are the same.
(also, NUM_TOTAL_PINS turns out to be 39, but the digital_pin_to_xxx[] arrays have 41 elements.)
I think there are:
20 normal digital and analog pins,
2 dedicated pins for I2C
3 dedicated pins for SPI on the ISP connector
1 dedicated LED (hey - 6 randomish pins, just like NUM_ANALOG_INPUTS, so it comes out ALMOST right.)
10 pins dedicated to the on-board IO (IMU, NINA, Debug USART),
1 pin that doesn't seem to be connected anywhere (PC3)
4 pins with dedicated functions TOSC1/2, VREF, RESET
Which adds up to the 41 IO pins that the datasheet mentions. (add UPDI and 6 power pins to total 48 pins on the package.)
(It looks like the only place that NUM_TOTAL_PINS is used, currently, is in the digitalPintoXXX() macros, range checking. So the extent of the actual "bug" is that Pin39 (VREF) and Pin40 (RESET) will not be usable for IO. Which is not very important...)
It would be nice to pin down exactly what these numbers are supposed to mean, since they appear to be part of the standard variant definitions.