94 lines
2.2 KiB
C
94 lines
2.2 KiB
C
/***************************************************************
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*
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* OpenBeacon.org - piezo speaker sound functions
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*
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* Copyright 2010 Milosch Meriac <meriac@openbeacon.de>
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*
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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 General Public License as published by
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the Free Software Foundation; version 2.
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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 General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program; if not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include <openbeacon.h>
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#include <sound.h>
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#ifdef SOUND_ENABLE
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#define ARRAY_COUNT(x) (sizeof(x)/sizeof(x[0]))
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void
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snd_beep (uint16_t frequency)
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{
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uint32_t t;
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LPC_TMR32B1->TCR = 0;
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if (frequency)
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{
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t = (SYSTEM_CORE_CLOCK / 2) / frequency;
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LPC_TMR32B1->MR0 = LPC_TMR32B1->MR1 = t;
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if (LPC_TMR32B1->TC >= t)
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LPC_TMR32B1->TC = t;
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LPC_TMR32B1->TCR = 1;
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}
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}
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static inline uint16_t
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snd_get_frequency_for_tone (uint8_t tone)
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{
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static const uint16_t frequency[] = { 26263, 29366, 32963, 34923, 39200, 44000, 49388 };
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return (((uint32_t) frequency[tone % ARRAY_COUNT (frequency)]) * (1 << (tone/ARRAY_COUNT(frequency))))/100;
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}
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void
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snd_tone (uint8_t tone)
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{
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static uint8_t lasttone = 0;
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if (tone != lasttone)
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{
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if (tone)
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{
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LPC_SYSCON->SYSAHBCLKCTRL |= EN_CT32B1;
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LPC_TMR32B1->EMR = 1 | (0x3 << 4) | (0x3 << 6);
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snd_beep (tone ? snd_get_frequency_for_tone (tone - 1) : 0);
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}
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else
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{
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LPC_TMR32B1->EMR = 0;
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LPC_SYSCON->SYSAHBCLKCTRL &= ~EN_CT32B1;
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}
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lasttone = tone;
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}
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}
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void
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snd_init (void)
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{
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/* Set sound port to PIO1_1 and PIO1_2 */
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LPC_GPIO1->DIR |= 0x6;
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LPC_IOCON->JTAG_TDO_PIO1_1 = 3;
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LPC_IOCON->JTAG_nTRST_PIO1_2 = 3;
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/* run 32 bit timer for sound generation */
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LPC_SYSCON->SYSAHBCLKCTRL |= EN_CT32B1;
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LPC_TMR32B1->TCR = 2;
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LPC_TMR32B1->MCR = 1 << 4;
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LPC_TMR32B1->EMR = 0;
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}
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#endif /*SOUND_ENABLE */
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