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- Committer: Dan
- Date: 2011-11-03 00:18:13 UTC
- Revision ID: dan@waxworlds.org-20111103001813-gwefcqb2m5mk1ye2
Added Notes
- files removed:
- .bzrignore
- project
- src
- src/util
- test
- test/fan-test
- test/led-test
- test/phantom-button-presses
- files renamed:
- src/Makefile => Makefile
- notes => Notes.rtf
added
removed
src/propeller-clock.ino
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/* -*- mode: c++; compile-command: "BOARD=pro5v make"; -*- */
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/*
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* propeller-clock.ino
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*
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* Copyright (C) 2011 Tim Marston <tim@ed.am> and Dan Marston.
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*
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* This file is part of propeller-clock (hereafter referred to as "this
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* program"). See http://ed.am/dev/software/arduino/propeller-clock for more
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* information.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published
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* by the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/******************************************************************************
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Set up:
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* a PC fan is wired up to a 12V power supply
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* the fan's SENSE (tachiometer) pin connected to pin 2 on the
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arduino.
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* the pins 4 to 13 on the arduino should directly drive an LED (the
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LED on pin 4 is in the centre of the clock face and the LED on pin
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13 is at the outside.
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* if a longer hand (and a larger clock face) is desired, pin 4 can be
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used to indirectly drive a transistor which in turn drives several
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LEDs that turn on anf off in unison in the centre of the clock.
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* a button should be attached to pin 3 that grounds it when pressed.
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* A DS1307 remote clock is connected via I2C on analog pins 4 and 5.
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Implementation details:
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* for a schematic, see ../project/propeller-clock.sch.
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* the timing of the drawing of the clock face is recalculated with
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every rotation of the propeller.
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* a PC fan actually sends 2 tachiometer pulses per revolution, so the
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software skips every other one. This means that the clock may
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appear upside-down if started with the propeller in the wrong
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position. You will need to experiment to dicsover the position that
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the propeller must be in when starting the clock.
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Usage instructions:
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* pressing the button cycles between variations of the current
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display mode.
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* pressing and holding the button for a second cycles between display
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modes (e.g., analogue and digital).
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* pressing and holding the button for 5 seconds enters "time set"
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mode. In this mode, the following applies:
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- the field that is being set flashes
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- pressing the button increments the field currently being set
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- pressing and holding the button for a second cycles through the
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fields that can be set
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- pressing and holding the button for 5 seconds sets the time and
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exits "time set" mode
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******************************************************************************/
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#include <Bounce.h>
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#include <DS1307.h>
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#include <Wire.h>
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//_____________________________________________________________________________
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// data
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// when non-zero, the time (in microseconds) of a new fan pulse that
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// has just occurred, which means that segment drawing needs to be
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// restarted
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static unsigned long new_pulse_at = 0;
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// the time (in microseconds) when the last fan pulse occurred
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static unsigned long last_pulse_at = 0;
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// duration (in microseconds) that a segment should be displayed
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static unsigned long segment_step = 0;
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// remainder after divisor and a tally of the remainders for each segment
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static unsigned long segment_step_sub_step = 0;
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static unsigned long segment_step_sub = 0;
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// flag to indicate that the drawing mode should be cycled to the next one
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static bool inc_draw_mode = false;
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// a bounce-managed button
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static Bounce button( 3, 50 );
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// the time
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static int time_hours = 0;
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static int time_minutes = 0;
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static int time_seconds = 0;
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// number of segments in a full display (rotation) is 60 (one per
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// second) times the desired number of sub-divisions of a second
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#define NUM_SECOND_SEGMENTS 5
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#define NUM_SEGMENTS ( 60 * NUM_SECOND_SEGMENTS )
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//_____________________________________________________________________________
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// code
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// check for button presses
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void checkButtons()
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{
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// update buttons
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button.update();
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// notice button presses
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if( button.risingEdge() )
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inc_draw_mode = true;
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}
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// keep track of time
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void trackTime()
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{
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// previous time and any carried-over milliseconds
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static unsigned long last_time = millis();
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static unsigned long carry = 0;
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// how many milliseonds have elapsed since we last checked?
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unsigned long next_time = millis();
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unsigned long delta = next_time - last_time + carry;
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// update the previous time and carried-over milliseconds
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last_time = next_time;
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carry = delta % 1000;
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// add the seconds that have passed to the time
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time_seconds += delta / 1000;
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while( time_seconds >= 60 ) {
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time_seconds -= 60;
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time_minutes++;
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if( time_minutes >= 60 ) {
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time_minutes -= 60;
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time_hours++;
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if( time_hours >= 24 )
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time_hours -= 24;
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}
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}
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}
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// turn an led on/off
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void ledOn( int num, bool on )
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{
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if( num < 0 || num > 9 ) return;
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// convert to pin no.
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num += 4;
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// pin 4 needs to be inverted (it's driving a PNP)
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// NOTE: PIN 4 TEMPORARILY DISABLED
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if( num == 4 ) on = true; //!on
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digitalWrite( num, on? HIGH : LOW );
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}
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// draw a segment for the test display
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void drawNextSegment_test( bool reset )
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{
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// keep track of segment
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static unsigned int segment = 0;
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if( reset ) segment = 0;
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segment++;
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// turn on inside and outside LEDs
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ledOn( 0, true );
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ledOn( 9, true );
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// display segment number in binary across in the inside LEDs,
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// with the LED on pin 12 showing the least-significant bit
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for( int a = 0; a < 8; a++ )
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ledOn( 8 - a, ( segment >> a ) & 1 );
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}
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// draw a segment for the time display
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void drawNextSegment_time( bool reset )
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{
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static int second = 0;
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static int segment = 0;
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// handle display reset
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if( reset ) {
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second = 0;
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segment = 0;
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}
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// what needs to be drawn?
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bool draw_tick = !segment && second % 5 == 0;
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bool draw_second = !segment && second == time_seconds;
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bool draw_minute = !segment && second == time_minutes;
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bool draw_hour = !segment && second == time_hours;
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// set the LEDs
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ledOn( 9, true );
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ledOn( 8, draw_tick || draw_minute );
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for( int a = 6; a <= 7; a++ )
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ledOn( a, draw_minute || draw_second );
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for( int a = 0; a <= 5; a++ )
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ledOn( a, draw_minute || draw_second || draw_hour );
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// inc position
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if( ++segment >= NUM_SECOND_SEGMENTS ) {
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segment = 0;
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second++;
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}
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}
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// draw a display segment
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void drawNextSegment( bool reset )
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{
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static int draw_mode = 0;
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// handle mode switch requests
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if( reset && inc_draw_mode ) {
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inc_draw_mode = false;
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draw_mode++;
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if( draw_mode >= 2 )
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draw_mode = 0;
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}
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// draw the segment
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switch( draw_mode ) {
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case 0: drawNextSegment_test( reset ); break;
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case 1: drawNextSegment_time( reset ); break;
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}
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}
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// calculate time constants when a new pulse has occurred
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void calculateSegmentTimes()
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{
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// check for overflows, and only recalculate times if there isn't
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// one (if there is, we'll just go with the last pulse's times)
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if( new_pulse_at > last_pulse_at )
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{
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// new segment stepping times
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unsigned long delta = new_pulse_at - last_pulse_at;
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segment_step = delta / NUM_SEGMENTS;
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segment_step_sub = 0;
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segment_step_sub_step = delta % NUM_SEGMENTS;
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}
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// now we have dealt with this pulse, save the pulse time and
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// clear new_pulse_at, ready for the next pulse
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last_pulse_at = new_pulse_at;
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new_pulse_at = 0;
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}
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// wait until it is time to draw the next segment or a new pulse has
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// occurred
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void waitTillNextSegment( bool reset )
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{
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static unsigned long end_time = 0;
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// handle reset
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if( reset )
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end_time = last_pulse_at;
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// work out the time that this segment should be displayed until
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end_time += segment_step;
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segment_step_sub += segment_step_sub_step;
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if( segment_step_sub >= NUM_SEGMENTS ) {
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segment_step_sub -= NUM_SEGMENTS;
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end_time++;
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}
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// wait
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while( micros() < end_time && !new_pulse_at );
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}
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// ISR to handle the pulses from the fan's tachiometer
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void fanPulseHandler()
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{
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// the fan actually sends two pulses per revolution. These pulses
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// may not be exactly evenly distributed around the rotation, so
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// we can't recalculate times on every pulse. Instead, we ignore
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// every other pulse so timings are based on a complete rotation.
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static bool ignore = true;
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ignore = !ignore;
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if( !ignore )
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{
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// set a new pulse time
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new_pulse_at = micros();
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}
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}
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// main setup
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void setup()
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{
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// set up an interrupt handler on pin 2 to nitice fan pulses
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attachInterrupt( 0, fanPulseHandler, RISING );
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digitalWrite( 2, HIGH );
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// set up output pins (4 to 13) for the led array
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for( int a = 4; a < 14; a++ )
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pinMode( a, OUTPUT );
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// set up mode-switch button on pin 3
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pinMode( 3, INPUT );
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digitalWrite( 3, HIGH );
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// get the time from the real-time clock
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int rtc_data[ 7 ];
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RTC.get( rtc_data, true );
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time_hours = rtc_data[ DS1307_HR ];
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time_minutes = rtc_data[ DS1307_MIN ];
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time_seconds = rtc_data[ DS1307_SEC ];
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// serial comms
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Serial.begin( 9600 );
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}
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// main loop
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void loop()
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{
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// if there has been a new pulse, we'll be resetting the display
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bool reset = new_pulse_at? true : false;
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// only do this stuff at the start of a display cycle, to ensure
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// that no state changes mid-display
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if( reset )
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{
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// check buttons
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checkButtons();
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// keep track of time
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trackTime();
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}
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// draw this segment
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drawNextSegment( reset );
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// do we need to recalculate segment times?
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if( reset )
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calculateSegmentTimes();
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// wait till it's time to draw the next segment
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waitTillNextSegment( reset );
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}
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