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
|
/*
* This file is subject to the terms of the GFX License. If a copy of
* the license was not distributed with this file, you can obtain one at:
*
* http://ugfx.io/license.html
*/
#ifndef GAUDIO_PLAY_BOARD_H
#define GAUDIO_PLAY_BOARD_H
/* Our timer callback */
static void gptcallback(GPTDriver *gptp) {
(void) gptp;
gaudio_play_pwm_timer_callbackI();
}
/* PWM configuration structure. The speaker is on PWM0/PB19 ie PWM1/PIN1 in ChibiOS speak */
static PWMConfig pwmcfg = {
1000000, /* 1 MHz PWM clock frequency. Ignored as we are using PWM_MCK_DIV_n */
1024, /* PWM period is 1024 cycles (10 bits). */
0,
{
{PWM_MCK_DIV_1 | PWM_OUTPUT_CENTER | PWM_OUTPUT_ACTIVE_HIGH | PWM_OUTPUT_PIN1 | PWM_DISABLEPULLUP_PIN1, 0},
},
};
/* Timer configuration structure. We use Timer 2 (TC1) */
static GPTConfig gptcfg = {
8192, // frequency
gptcallback, // callback
GPT_CLOCK_FREQUENCY, // clocksource
GPT_GATE_NONE, // clockgate
GPT_TRIGGER_NONE, // trigger
};
static gU16 lastvalue;
static gBool gaudio_play_pwm_setup(gU32 frequency, ArrayDataFormat format) {
if (format == ARRAY_DATA_10BITUNSIGNED)
pwmcfg.period = 1024;
else if (format == ARRAY_DATA_8BITUNSIGNED)
pwmcfg.period = 256;
else
return gFalse;
gptcfg.frequency = frequency;
return gTrue;
}
static void gaudio_play_pwm_start(void) {
/* Start the PWM */
pwmStart(&PWMD1, &pwmcfg);
lastvalue = pwmcfg.period>>1;
pwmEnableChannelI(&PWMD1, 0, lastvalue);
/* Start the timer interrupt */
gptStart(&GPTD2, &gptcfg);
gptStartContinuous(&GPTD2, 0);
}
static void gaudio_play_pwm_stop(void) {
/* Stop the timer interrupt */
gptStopTimer(&GPTD2);
/* Stop the PWM */
pwmStop(&PWMD1);
}
static void gaudio_play_pwm_setI(gU16 value) {
if (value != lastvalue) {
lastvalue = value;
pwmEnableChannelI(&PWMD1, 0, value);
}
}
#endif /* GAUDIO_PLAY_BOARD_H */
|
