/
MsTimer2.cpp
206 lines (185 loc) · 6.36 KB
/
MsTimer2.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
/*
MsTimer2.h - Using timer2 with 1ms resolution
Javier Valencia <javiervalencia80@gmail.com>
History:
29/Dec/11 - V0.6 added support for ATmega32u4, AT90USB646, AT90USB1286 (paul@pjrc.com)
some improvements added by Bill Perry
note: uses timer4 on Atmega32u4
29/May/09 - V0.5 added support for Atmega1280 (thanks to Manuel Negri)
19/Mar/09 - V0.4 added support for ATmega328P (thanks to Jerome Despatis)
11/Jun/08 - V0.3
changes to allow working with different CPU frequencies
added support for ATMega128 (using timer2)
compatible with ATMega48/88/168/8
10/May/08 - V0.2 added some security tests and volatile keywords
9/May/08 - V0.1 released working on ATMEGA168 only
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <MsTimer2.h>
unsigned long MsTimer2::msecs;
void (*MsTimer2::func)();
volatile unsigned long MsTimer2::count;
volatile char MsTimer2::overflowing;
volatile unsigned int MsTimer2::tcnt2;
void MsTimer2::set(unsigned long ms, void (*f)()) {
float prescaler = 0.0;
if (ms == 0)
msecs = 1;
else
msecs = ms;
func = f;
#if defined (__AVR_ATmega168__) || defined (__AVR_ATmega48__) || defined (__AVR_ATmega88__) || defined (__AVR_ATmega328P__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__) || defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB1286__)
TIMSK2 &= ~(1<<TOIE2);
TCCR2A &= ~((1<<WGM21) | (1<<WGM20));
TCCR2B &= ~(1<<WGM22);
ASSR &= ~(1<<AS2);
TIMSK2 &= ~(1<<OCIE2A);
if ((F_CPU >= 1000000UL) && (F_CPU <= 16000000UL)) { // prescaler set to 64
TCCR2B |= (1<<CS22);
TCCR2B &= ~((1<<CS21) | (1<<CS20));
prescaler = 64.0;
} else if (F_CPU < 1000000UL) { // prescaler set to 8
TCCR2B |= (1<<CS21);
TCCR2B &= ~((1<<CS22) | (1<<CS20));
prescaler = 8.0;
} else { // F_CPU > 16Mhz, prescaler set to 128
TCCR2B |= ((1<<CS22) | (1<<CS20));
TCCR2B &= ~(1<<CS21);
prescaler = 128.0;
}
#elif defined (__AVR_ATmega8__)
TIMSK &= ~(1<<TOIE2);
TCCR2 &= ~((1<<WGM21) | (1<<WGM20));
TIMSK &= ~(1<<OCIE2);
ASSR &= ~(1<<AS2);
if ((F_CPU >= 1000000UL) && (F_CPU <= 16000000UL)) { // prescaler set to 64
TCCR2 |= (1<<CS22);
TCCR2 &= ~((1<<CS21) | (1<<CS20));
prescaler = 64.0;
} else if (F_CPU < 1000000UL) { // prescaler set to 8
TCCR2 |= (1<<CS21);
TCCR2 &= ~((1<<CS22) | (1<<CS20));
prescaler = 8.0;
} else { // F_CPU > 16Mhz, prescaler set to 128
TCCR2 |= ((1<<CS22) && (1<<CS20));
TCCR2 &= ~(1<<CS21);
prescaler = 128.0;
}
#elif defined (__AVR_ATmega128__)
TIMSK &= ~(1<<TOIE2);
TCCR2 &= ~((1<<WGM21) | (1<<WGM20));
TIMSK &= ~(1<<OCIE2);
if ((F_CPU >= 1000000UL) && (F_CPU <= 16000000UL)) { // prescaler set to 64
TCCR2 |= ((1<<CS21) | (1<<CS20));
TCCR2 &= ~(1<<CS22);
prescaler = 64.0;
} else if (F_CPU < 1000000UL) { // prescaler set to 8
TCCR2 |= (1<<CS21);
TCCR2 &= ~((1<<CS22) | (1<<CS20));
prescaler = 8.0;
} else { // F_CPU > 16Mhz, prescaler set to 256
TCCR2 |= (1<<CS22);
TCCR2 &= ~((1<<CS21) | (1<<CS20));
prescaler = 256.0;
}
#elif defined (__AVR_ATmega32U4__)
TCCR4B = 0;
TCCR4A = 0;
TCCR4C = 0;
TCCR4D = 0;
TCCR4E = 0;
if (F_CPU >= 16000000L) {
TCCR4B = (1<<CS43) | (1<<PSR4);
prescaler = 128.0;
} else if (F_CPU >= 8000000L) {
TCCR4B = (1<<CS42) | (1<<CS41) | (1<<CS40) | (1<<PSR4);
prescaler = 64.0;
} else if (F_CPU >= 4000000L) {
TCCR4B = (1<<CS42) | (1<<CS41) | (1<<PSR4);
prescaler = 32.0;
} else if (F_CPU >= 2000000L) {
TCCR4B = (1<<CS42) | (1<<CS40) | (1<<PSR4);
prescaler = 16.0;
} else if (F_CPU >= 1000000L) {
TCCR4B = (1<<CS42) | (1<<PSR4);
prescaler = 8.0;
} else if (F_CPU >= 500000L) {
TCCR4B = (1<<CS41) | (1<<CS40) | (1<<PSR4);
prescaler = 4.0;
} else {
TCCR4B = (1<<CS41) | (1<<PSR4);
prescaler = 2.0;
}
tcnt2 = (int)((float)F_CPU * 0.001 / prescaler) - 1;
OCR4C = tcnt2;
return;
#else
#error Unsupported CPU type
#endif
tcnt2 = 256 - (int)((float)F_CPU * 0.001 / prescaler);
}
void MsTimer2::start() {
count = 0;
overflowing = 0;
#if defined (__AVR_ATmega168__) || defined (__AVR_ATmega48__) || defined (__AVR_ATmega88__) || defined (__AVR_ATmega328P__) || defined (__AVR_ATmega1280__) || defined(__AVR_ATmega2560__) || defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB1286__)
TCNT2 = tcnt2;
TIMSK2 |= (1<<TOIE2);
#elif defined (__AVR_ATmega128__)
TCNT2 = tcnt2;
TIMSK |= (1<<TOIE2);
#elif defined (__AVR_ATmega8__)
TCNT2 = tcnt2;
TIMSK |= (1<<TOIE2);
#elif defined (__AVR_ATmega32U4__)
TIFR4 = (1<<TOV4);
TCNT4 = 0;
TIMSK4 = (1<<TOIE4);
#endif
}
void MsTimer2::stop() {
#if defined (__AVR_ATmega168__) || defined (__AVR_ATmega48__) || defined (__AVR_ATmega88__) || defined (__AVR_ATmega328P__) || defined (__AVR_ATmega1280__) || defined(__AVR_ATmega2560__) || defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB1286__)
TIMSK2 &= ~(1<<TOIE2);
#elif defined (__AVR_ATmega128__)
TIMSK &= ~(1<<TOIE2);
#elif defined (__AVR_ATmega8__)
TIMSK &= ~(1<<TOIE2);
#elif defined (__AVR_ATmega32U4__)
TIMSK4 = 0;
#endif
}
void MsTimer2::_overflow() {
count += 1;
if (count >= msecs && !overflowing) {
overflowing = 1;
count = count - msecs; // subtract ms to catch missed overflows
// set to 0 if you don't want this.
(*func)();
overflowing = 0;
}
}
#if defined (__AVR_ATmega32U4__)
ISR(TIMER4_OVF_vect) {
#else
ISR(TIMER2_OVF_vect) {
#endif
#if defined (__AVR_ATmega168__) || defined (__AVR_ATmega48__) || defined (__AVR_ATmega88__) || defined (__AVR_ATmega328P__) || defined (__AVR_ATmega1280__) || defined(__AVR_ATmega2560__) || defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB1286__)
TCNT2 = MsTimer2::tcnt2;
#elif defined (__AVR_ATmega128__)
TCNT2 = MsTimer2::tcnt2;
#elif defined (__AVR_ATmega8__)
TCNT2 = MsTimer2::tcnt2;
#elif defined (__AVR_ATmega32U4__)
// not necessary on 32u4's high speed timer4
#endif
MsTimer2::_overflow();
}