Make Arduino timer stuff work on Contiki

New discovery: Contiki also uses timer 0. With almost the same interface
as Arduino. So we now completely get rid of wiring.c (only the main
file, the other wiring_xxx stay) and implement Arduino timer, delay, etc
in terms of the corresponding Contiki routines. Verified that now delay
works as expected. The LED in examples/osd/arduino-sketch blinks!

Before this, the arduino_init routine in wiring.c destroyed the timer-0
initialization of contiki, making both, contiki timer implementation
*and* contiki timer implementation fail if the arduino_init routine was
called. Now both work.

Squashed with following bug-fix commit.
This commit is contained in:
Ralf Schlatterbeck 2014-06-26 18:37:13 +02:00
parent 08abd8807d
commit c46d6afa39
7 changed files with 61 additions and 273 deletions

View file

@ -50,6 +50,8 @@
*/
#include "arduino-process.h"
#include "hw_timer.h"
#include "hw-arduino.h"
PROCESS(arduino_sketch, "Arduino Sketch Wrapper");
@ -57,7 +59,7 @@ PROCESS_THREAD(arduino_sketch, ev, data)
{
PROCESS_BEGIN();
arduino_init ();
arduino_pwm_timer_init ();
setup ();
while (1) {
loop ();

View file

@ -62,6 +62,7 @@ led_pwm_handler
const uint16_t *accept = NULL;
uint16_t a_ctype = REST.type.APPLICATION_JSON;
uint16_t c_ctype = REST.get_header_content_type (request);
uint32_t tmp = 0;
/* Seems like accepted type is currently unsupported? */
n_acc = REST.get_header_accept (request, &accept);
@ -136,7 +137,11 @@ led_pwm_handler
temp [sizeof (temp) - 1] = 0;
}
PRINTF ("GOT: %s\n", temp);
pwm = atoi (temp);
tmp = strtoul (temp, NULL, 10);
if (tmp > 255) {
tmp = 255;
}
pwm = tmp;
PRINTF ("Setting: %d\n", pwm);
REST.set_response_status(response, REST.status.CHANGED);
} else {
@ -181,6 +186,7 @@ led_period_handler
const uint16_t *accept = NULL;
uint16_t a_ctype = REST.type.APPLICATION_JSON;
uint16_t c_ctype = REST.get_header_content_type (request);
uint32_t tmp = 0;
/* Seems like accepted type is currently unsupported? */
n_acc = REST.get_header_accept (request, &accept);
@ -255,7 +261,14 @@ led_period_handler
temp [sizeof (temp) - 1] = 0;
}
PRINTF ("GOT: %s\n", temp);
period_100ms = (atoi (temp) + 50) / 100;
tmp = (strtoul (temp, NULL, 10) + 50) / 100;
if (tmp > 10) {
tmp = 10;
}
if (tmp == 0) {
tmp = 1;
}
period_100ms = tmp;
PRINTF ("Setting: %dms\n", period_100ms * 100);
REST.set_response_status(response, REST.status.CHANGED);
} else {

View file

@ -28,20 +28,10 @@ void setup (void)
void loop (void)
{
static uint8_t last_pwm = 0;
if (last_pwm != pwm) {
last_pwm = pwm;
analogWrite (LED_PIN, pwm);
printf
( "TCNT3: %04X TCCR3A: %04X TCCR3B: %04X TCCR3C: %04X OCR3C: %04X\n"
, TCNT3, TCCR3A, TCCR3B, TCCR3C, OCR3C
);
}
// Originally I wanted to sleep here to make the LED blink.
// Sleeping currently doesn't work, something turns off the chip.
// Maybe a mechanism to guard agains proto-threads taking too long?
//clock_wait (CLOCK_SECOND * period_100ms / 10);
//analogWrite (LED_PIN, 0);
//printf ("After write\n");
/* Use 255 - pwm, LED on merkur-board is wired to +3.3V */
analogWrite (LED_PIN, 255 - pwm);
printf ("clock : %u\nmillis: %lu\n", clock_time (), millis ());
delay (period_100ms * 100);
analogWrite (LED_PIN, 255); /* OFF: LED on merkur-board is wired to +3.3V */
delay (period_100ms * 100);
}

View file

@ -27,7 +27,7 @@ CONTIKI_TARGET_SOURCEFILES += servo.c servo-sensor.c
#Needed for Relay 1 to 4
CONTIKI_TARGET_SOURCEFILES += relay.c relay-sensor.c
# Arduino
CONTIKI_TARGET_SOURCEFILES += wiring_digital.c wiring.c wiring_analog.c
CONTIKI_TARGET_SOURCEFILES += wiring_digital.c wiring_analog.c
CONTIKIBOARD=.
BOOTLOADER_START = 0x1F000

View file

@ -69,10 +69,6 @@ extern "C"{
#define interrupts() sei()
#define noInterrupts() cli()
#define clockCyclesPerMicrosecond() ( F_CPU / 1000000L )
#define clockCyclesToMicroseconds(a) ( (a) / clockCyclesPerMicrosecond() )
#define microsecondsToClockCycles(a) ( (a) * clockCyclesPerMicrosecond() )
#define lowByte(w) ((uint8_t) ((w) & 0xff))
#define highByte(w) ((uint8_t) ((w) >> 8))
@ -102,10 +98,6 @@ int digitalRead(uint8_t);
int analogRead(uint8_t);
void analogReference(uint8_t mode);
unsigned long millis(void);
unsigned long micros(void);
void delay(unsigned long);
void delayMicroseconds(unsigned int us);
unsigned long pulseIn(uint8_t pin, uint8_t state, unsigned long timeout);
void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val);

View file

@ -48,6 +48,12 @@
*
*/
#ifdef __cplusplus
extern "C"{
#endif
#include "contiki.h"
/*
* The OSD hardware only supports timer 3 for PWM, timer 2 is used by
* contiki for sleep/wakeup timing and is not usable for PWM.
@ -65,9 +71,39 @@
#define arduino_pwm_timer_init() \
(hwtimer_ini (3, HWT_WGM_PWM_PHASE_8_BIT, HWT_CLOCK_PRESCALER_64, 0))
/*
* micros on arduino takes timer overflows into account.
* We put in the seconds counter. To get a consistent seconds / ticks
* value we have to disable interrupts.
*/
static inline uint32_t micros (void)
{
uint32_t ticks;
uint8_t sreg = SREG;
cli ();
ticks = clock_seconds () * 1000000L
+ clock_time () * 1000L / CLOCK_SECOND;
SREG = sreg;
return ticks;
}
/*
* millis counts only internal timer ticks since start, not trying to do
* something about overflows. Note that we don't try to emulate overflow
* behaviour of arduino implementation.
*/
#define millis() (((uint32_t)clock_time())*1000L/CLOCK_SECOND)
#define micros() (clock_seconds()*1000L+
#define delay(ms) clock_delay_msec(ms)
#define delayMicroseconds(us) clock_delay_usec(us)
/*
* VI settings, see coding style
* ex:ts=8:et:sw=2
*/
#ifdef __cplusplus
} // extern "C"
#endif
/** @} */

View file

@ -1,245 +0,0 @@
/*
wiring.c - Partial implementation of the Wiring API for the ATmega8.
Part of Arduino - http://www.arduino.cc/
Copyright (c) 2005-2006 David A. Mellis
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General
Public License along with this library; if not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330,
Boston, MA 02111-1307 USA
$Id$
*/
#include "wiring_private.h"
#include "hw-arduino.h"
// the prescaler is set so that timer0 ticks every 64 clock cycles, and the
// the overflow handler is called every 256 ticks.
#define MICROSECONDS_PER_TIMER0_OVERFLOW (clockCyclesToMicroseconds(64 * 256))
// the whole number of milliseconds per timer0 overflow
#define MILLIS_INC (MICROSECONDS_PER_TIMER0_OVERFLOW / 1000)
// the fractional number of milliseconds per timer0 overflow. we shift right
// by three to fit these numbers into a byte. (for the clock speeds we care
// about - 8 and 16 MHz - this doesn't lose precision.)
#define FRACT_INC ((MICROSECONDS_PER_TIMER0_OVERFLOW % 1000) >> 3)
#define FRACT_MAX (1000 >> 3)
volatile unsigned long timer0_overflow_count = 0;
volatile unsigned long timer0_millis = 0;
static unsigned char timer0_fract = 0;
#if defined(__AVR_ATtiny24__) || defined(__AVR_ATtiny44__) || defined(__AVR_ATtiny84__)
SIGNAL(TIM0_OVF_vect)
#else
SIGNAL(TIMER0_OVF_vect)
#endif
{
// copy these to local variables so they can be stored in registers
// (volatile variables must be read from memory on every access)
unsigned long m = timer0_millis;
unsigned char f = timer0_fract;
m += MILLIS_INC;
f += FRACT_INC;
if (f >= FRACT_MAX) {
f -= FRACT_MAX;
m += 1;
}
timer0_fract = f;
timer0_millis = m;
timer0_overflow_count++;
}
unsigned long millis()
{
unsigned long m;
uint8_t oldSREG = SREG;
// disable interrupts while we read timer0_millis or we might get an
// inconsistent value (e.g. in the middle of a write to timer0_millis)
cli();
m = timer0_millis;
SREG = oldSREG;
return m;
}
unsigned long micros() {
unsigned long m;
uint8_t oldSREG = SREG, t;
cli();
m = timer0_overflow_count;
#if defined(TCNT0)
t = TCNT0;
#elif defined(TCNT0L)
t = TCNT0L;
#else
#error TIMER 0 not defined
#endif
#ifdef TIFR0
if ((TIFR0 & _BV(TOV0)) && (t < 255))
m++;
#else
if ((TIFR & _BV(TOV0)) && (t < 255))
m++;
#endif
SREG = oldSREG;
return ((m << 8) + t) * (64 / clockCyclesPerMicrosecond());
}
void delay(unsigned long ms)
{
uint16_t start = (uint16_t)micros();
while (ms > 0) {
if (((uint16_t)micros() - start) >= 1000) {
ms--;
start += 1000;
}
}
}
/* Delay for the given number of microseconds. Assumes a 8 or 16 MHz clock. */
void delayMicroseconds(unsigned int us)
{
// calling avrlib's delay_us() function with low values (e.g. 1 or
// 2 microseconds) gives delays longer than desired.
//delay_us(us);
#if F_CPU >= 20000000L
// for the 20 MHz clock on rare Arduino boards
// for a one-microsecond delay, simply wait 2 cycle and return. The overhead
// of the function call yields a delay of exactly a one microsecond.
__asm__ __volatile__ (
"nop" "\n\t"
"nop"); //just waiting 2 cycle
if (--us == 0)
return;
// the following loop takes a 1/5 of a microsecond (4 cycles)
// per iteration, so execute it five times for each microsecond of
// delay requested.
us = (us<<2) + us; // x5 us
// account for the time taken in the preceeding commands.
us -= 2;
#elif F_CPU >= 16000000L
// for the 16 MHz clock on most Arduino boards
// for a one-microsecond delay, simply return. the overhead
// of the function call yields a delay of approximately 1 1/8 us.
if (--us == 0)
return;
// the following loop takes a quarter of a microsecond (4 cycles)
// per iteration, so execute it four times for each microsecond of
// delay requested.
us <<= 2;
// account for the time taken in the preceeding commands.
us -= 2;
#else
// for the 8 MHz internal clock on the ATmega168
// for a one- or two-microsecond delay, simply return. the overhead of
// the function calls takes more than two microseconds. can't just
// subtract two, since us is unsigned; we'd overflow.
if (--us == 0)
return;
if (--us == 0)
return;
// the following loop takes half of a microsecond (4 cycles)
// per iteration, so execute it twice for each microsecond of
// delay requested.
us <<= 1;
// partially compensate for the time taken by the preceeding commands.
// we can't subtract any more than this or we'd overflow w/ small delays.
us--;
#endif
// busy wait
__asm__ __volatile__ (
"1: sbiw %0,1" "\n\t" // 2 cycles
"brne 1b" : "=w" (us) : "0" (us) // 2 cycles
);
}
void arduino_init()
{
// this needs to be called before setup() or some functions won't
// work there
// on the ATmega168, timer 0 is also used for fast hardware pwm
// (using phase-correct PWM would mean that timer 0 overflowed half as often
// resulting in different millis() behavior on the ATmega8 and ATmega168)
/*
* RSC: Keep timer0 for now, until we decide how to implement
* millis() etc in a contiki-compatible way
*/
#if defined(TCCR0A) && defined(WGM01)
sbi(TCCR0A, WGM01);
sbi(TCCR0A, WGM00);
#endif
// set timer 0 prescale factor to 64
#if defined(__AVR_ATmega128__)
// CPU specific: different values for the ATmega128
sbi(TCCR0, CS02);
#elif defined(TCCR0) && defined(CS01) && defined(CS00)
// this combination is for the standard atmega8
sbi(TCCR0, CS01);
sbi(TCCR0, CS00);
#elif defined(TCCR0B) && defined(CS01) && defined(CS00)
// this combination is for the standard 168/328/1280/2560
sbi(TCCR0B, CS01);
sbi(TCCR0B, CS00);
#elif defined(TCCR0A) && defined(CS01) && defined(CS00)
// this combination is for the __AVR_ATmega645__ series
sbi(TCCR0A, CS01);
sbi(TCCR0A, CS00);
#else
#error Timer 0 prescale factor 64 not set correctly
#endif
// enable timer 0 overflow interrupt
#if defined(TIMSK) && defined(TOIE0)
sbi(TIMSK, TOIE0);
#elif defined(TIMSK0) && defined(TOIE0)
sbi(TIMSK0, TOIE0);
#else
#error Timer 0 overflow interrupt not set correctly
#endif
/*
* All other PCM timers are initialized here in a
* platform-specific way
*/
arduino_pwm_timer_init ();
/*
* Removed the rest which manipulates the serial pins
*/
}