Creating an entry for mega1284P-MU

Other Hardware 3rd Party Boards
1

Hi all,

I've used the Mighty 1284P files in the past with good success, however - I'm working on a device with a 1284P-MU, the 44pin QFN version. It has a few more GP IO pins and is mapped different in terms of pin numbers, so clearly I need to play with some files.

Here's the full pins file for the might 1284p with a 'standard' pinout.

#ifndef Pins_Arduino_h
#define Pins_Arduino_h

#include <avr/pgmspace.h>

// ATMEL ATMEGA1284P

/*
   PCINT15-8: D7-0  : bit 1
   PCINT31-24: D15-8  : bit 3
   PCINT23-16: D23-16 : bit 2
   PCINT7-0: D31-24   : bit 0
   */

#define NUM_DIGITAL_PINS            31
#define NUM_ANALOG_INPUTS           8
#define analogInputToDigitalPin(p)  ((p < NUM_ANALOG_INPUTS) ? (p) + 24 : -1)

#define digitalPinHasPWM(p)         ((p) == 3 || (p) == 4 || (p) == 6 || (p) == 7 || (p) == 12 || (p) == 13 || (p) == 14 || (p) == 15)

static const uint8_t SS   = 4;
static const uint8_t MOSI = 5;
static const uint8_t MISO = 6;
static const uint8_t SCK  = 7;

static const uint8_t SDA = 17;
static const uint8_t SCL = 16;
static const uint8_t LED = 7;

static const uint8_t A0 = 24;
static const uint8_t A1 = 25;
static const uint8_t A2 = 26;
static const uint8_t A3 = 27;
static const uint8_t A4 = 28;
static const uint8_t A5 = 29;
static const uint8_t A6 = 30;
static const uint8_t A7 = 31;

#define digitalPinToPCICR(p)    (((p) >= 0 && (p) < NUM_DIGITAL_PINS) ? (&PCICR) : ((uint8_t *)0))
#define digitalPinToPCICRbit(p) (((p) <= 7) ? 1 : (((p) <= 15) ? 3 : (((p) <= 23) ? 2 : 0)))
#define digitalPinToPCMSK(p)    (((p) <= 7) ? (&PCMSK2) : (((p) <= 13) ? (&PCMSK0) : (((p) <= 21) ? (&PCMSK1) : ((uint8_t *)0))))
#define digitalPinToPCMSKbit(p) ((p) % 8)

#ifdef ARDUINO_MAIN

#define PA 1
#define PB 2
#define PC 3
#define PD 4

// these arrays map port names (e.g. port B) to the
// appropriate addresses for various functions (e.g. reading
// and writing)
const uint16_t PROGMEM port_to_mode_PGM[] =
{
	NOT_A_PORT,
	(uint16_t) &DDRA,
	(uint16_t) &DDRB,
	(uint16_t) &DDRC,
	(uint16_t) &DDRD,
};

const uint16_t PROGMEM port_to_output_PGM[] =
{
	NOT_A_PORT,
	(uint16_t) &PORTA,
	(uint16_t) &PORTB,
	(uint16_t) &PORTC,
	(uint16_t) &PORTD,
};

const uint16_t PROGMEM port_to_input_PGM[] =
{
	NOT_A_PORT,
	(uint16_t) &PINA,
	(uint16_t) &PINB,
	(uint16_t) &PINC,
	(uint16_t) &PIND,
};

const uint8_t PROGMEM digital_pin_to_port_PGM[] =
{
	PB, /* 0 */
	PB,
	PB,
	PB,
	PB,
	PB,
	PB,
	PB,
	PD, /* 8 */
	PD,
	PD,
	PD,
	PD,
	PD,
	PD,
	PD,
	PC, /* 16 */
	PC,
	PC,
	PC,
	PC,
	PC,
   	PC,
	PC,
	PA, /* 24 */
	PA,
	PA,
	PA,
	PA,
	PA,
	PA,
	PA  /* 31 */
};

const uint8_t PROGMEM digital_pin_to_bit_mask_PGM[] =
{
	_BV(0), /* 0, port B */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(6),
	_BV(7),
	_BV(0), /* 8, port D */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(6),
	_BV(7),
	_BV(0), /* 16, port C */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(6),
	_BV(7),
	_BV(0), /* 24, port A */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(6),
	_BV(7)
};

const uint8_t PROGMEM digital_pin_to_timer_PGM[] =
{
	NOT_ON_TIMER, 	/* 0  - PB0 */
	NOT_ON_TIMER, 	/* 1  - PB1 */
	NOT_ON_TIMER, 	/* 2  - PB2 */
	TIMER0A,     	/* 3  - PB3 */
	TIMER0B, 	/* 4  - PB4 */
	NOT_ON_TIMER, 	/* 5  - PB5 */
	TIMER3A, 	/* 6  - PB6 */
	TIMER3B,	/* 7  - PB7 */
	NOT_ON_TIMER, 	/* 8  - PD0 */
	NOT_ON_TIMER, 	/* 9  - PD1 */
	NOT_ON_TIMER, 	/* 10 - PD2 */
	NOT_ON_TIMER, 	/* 11 - PD3 */
	TIMER1B,     	/* 12 - PD4 */
	TIMER1A,     	/* 13 - PD5 */
	TIMER2B,     	/* 14 - PD6 */
	TIMER2A,     	/* 15 - PD7 */
	NOT_ON_TIMER, 	/* 16 - PC0 */
	NOT_ON_TIMER,   /* 17 - PC1 */
	NOT_ON_TIMER,   /* 18 - PC2 */
	NOT_ON_TIMER,   /* 19 - PC3 */
	NOT_ON_TIMER,   /* 20 - PC4 */
	NOT_ON_TIMER,   /* 21 - PC5 */
	NOT_ON_TIMER,   /* 22 - PC6 */
	NOT_ON_TIMER,   /* 23 - PC7 */
	NOT_ON_TIMER,   /* 24 - PA0 */
	NOT_ON_TIMER,   /* 25 - PA1 */
	NOT_ON_TIMER,   /* 26 - PA2 */
	NOT_ON_TIMER,   /* 27 - PA3 */
	NOT_ON_TIMER,   /* 28 - PA4 */
	NOT_ON_TIMER,   /* 29 - PA5 */
	NOT_ON_TIMER,   /* 30 - PA6 */
	NOT_ON_TIMER   /* 31 - PA7 */
};

#endif // ARDUINO_MAIN

#endif // Pins_Arduino_h
// vim:ai:cin:sts=2 sw=2 ft=cpp

Personally, with my new pin mapping, I'd much rather just map pin numbers to physical pin numbers - and remove the extra layer of abstraction, as the package is not a DIP package on a breadboard, so it's of little help to number them any other way.

Assigning the SPI, I2C and analog pins is trivial, but what about the "static const uint8_t LED = 7;" line, LED - what LED?

No idea what these are doing...

// these arrays map port names (e.g. port B) to the
// appropriate addresses for various functions (e.g. reading
// and writing)
const uint16_t PROGMEM port_to_mode_PGM[] =
{
[u]	NOT_A_PORT,
	(uint16_t) &DDRA,
	(uint16_t) &DDRB,
	(uint16_t) &DDRC,
	(uint16_t) &DDRD,
};

const uint16_t PROGMEM port_to_output_PGM[] =
{
	NOT_A_PORT,
	(uint16_t) &PORTA,
	(uint16_t) &PORTB,
	(uint16_t) &PORTC,
	(uint16_t) &PORTD,
};

const uint16_t PROGMEM port_to_input_PGM[] =
{
	NOT_A_PORT,
	(uint16_t) &PINA,
	(uint16_t) &PINB,
	(uint16_t) &PINC,
	(uint16_t) &PIND,
};

These surely assign which pins are part of which port?

const uint8_t PROGMEM digital_pin_to_port_PGM[] =
{
	PB, /* 0 */
	PB,
	PB,
	PB,
	PB,
	PB,
	PB,
	PB,
	PD, /* 8 */
	PD,
	PD,
	PD,
	PD,
	PD,
	PD,
	PD,
	PC, /* 16 */
	PC,
	PC,
	PC,
	PC,
	PC,
   	PC,
	PC,
	PA, /* 24 */
	PA,
	PA,
	PA,
	PA,
	PA,
	PA,
	PA  /* 31 */
};

These lines must shift the pin numbers in to each port name - why?

const uint8_t PROGMEM digital_pin_to_bit_mask_PGM[] =
{
	_BV(0), /* 0, port B */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(6),
	_BV(7),
	_BV(0), /* 8, port D */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(6),
	_BV(7),
	_BV(0), /* 16, port C */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(6),
	_BV(7),
	_BV(0), /* 24, port A */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(6),
	_BV(7)
};

These lines clearly assign which pin is on a timer, and which pin is not.

const uint8_t PROGMEM digital_pin_to_timer_PGM[] =
{
	NOT_ON_TIMER, 	/* 0  - PB0 */
	NOT_ON_TIMER, 	/* 1  - PB1 */
	NOT_ON_TIMER, 	/* 2  - PB2 */
	TIMER0A,     	/* 3  - PB3 */
	TIMER0B, 	/* 4  - PB4 */
	NOT_ON_TIMER, 	/* 5  - PB5 */
	TIMER3A, 	/* 6  - PB6 */
	TIMER3B,	/* 7  - PB7 */
	NOT_ON_TIMER, 	/* 8  - PD0 */
	NOT_ON_TIMER, 	/* 9  - PD1 */
	NOT_ON_TIMER, 	/* 10 - PD2 */
	NOT_ON_TIMER, 	/* 11 - PD3 */
	TIMER1B,     	/* 12 - PD4 */
	TIMER1A,     	/* 13 - PD5 */
	TIMER2B,     	/* 14 - PD6 */
	TIMER2A,     	/* 15 - PD7 */
	NOT_ON_TIMER, 	/* 16 - PC0 */
	NOT_ON_TIMER,   /* 17 - PC1 */
	NOT_ON_TIMER,   /* 18 - PC2 */
	NOT_ON_TIMER,   /* 19 - PC3 */
	NOT_ON_TIMER,   /* 20 - PC4 */
	NOT_ON_TIMER,   /* 21 - PC5 */
	NOT_ON_TIMER,   /* 22 - PC6 */
	NOT_ON_TIMER,   /* 23 - PC7 */
	NOT_ON_TIMER,   /* 24 - PA0 */
	NOT_ON_TIMER,   /* 25 - PA1 */
	NOT_ON_TIMER,   /* 26 - PA2 */
	NOT_ON_TIMER,   /* 27 - PA3 */
	NOT_ON_TIMER,   /* 28 - PA4 */
	NOT_ON_TIMER,   /* 29 - PA5 */
	NOT_ON_TIMER,   /* 30 - PA6 */
	NOT_ON_TIMER   /* 31 - PA7 */

What about these remaining lines - it looks like digitalPinHasPWM is the digital pin number that is associated with an output compare channel? What about the very last line in the below code snippet?

[u]#define analogInputToDigitalPin(p)  ((p < NUM_ANALOG_INPUTS) ? (p) + 24 : -1)[/u]

#define digitalPinHasPWM(p)         ((p) == 3 || (p) == 4 || (p) == 6 || (p) == 7 || (p) == 12 || (p) == 13 || (p) == 14 || (p) == 15)

#define digitalPinToPCICR(p)    (((p) >= 0 && (p) < NUM_DIGITAL_PINS) ? (&PCICR) : ((uint8_t *)0))
#define digitalPinToPCICRbit(p) (((p) <= 7) ? 1 : (((p) <= 15) ? 3 : (((p) <= 23) ? 2 : 0)))
#define digitalPinToPCMSK(p)    (((p) <= 7) ? (&PCMSK2) : (((p) <= 13) ? (&PCMSK0) : (((p) <= 21) ? (&PCMSK1) : ((uint8_t *)0))))
#define digitalPinToPCMSKbit(p) ((p) % 8)[/u]

// vim:ai:cin:sts=2 sw=2 ft=cpp

The device will also have a different device signature, which I presume I will need to change in the avrdude boards conf file - what else should I be looking at changing?

Many thanks in advance!