1 files changed, 82 insertions, 0 deletions
diff --git a/demos/LPC214x-GCC/buzzer.c b/demos/LPC214x-GCC/buzzer.c
new file mode 100644
index 000000000..4700bfb45
--- /dev/null
+++ b/demos/LPC214x-GCC/buzzer.c
@@ -0,0 +1,82 @@
+/*
+    ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
+
+    This file is part of ChibiOS/RT.
+
+    ChibiOS/RT is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    ChibiOS/RT 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ * Buzzer driver for Olimex LPC-P2148.
+ * Uses the timer 1 for wave generation and a Virtual Timer for the sound
+ * duration.
+ * The driver also generates an event when the sound is done and the buzzer
+ * goes silent.
+ */
+#include <ch.h>
+
+#include "lpc214x.h"
+#include "buzzer.h"
+
+EventSource BuzzerSilentEventSource;
+
+#define StartCounter(t) ((t)->TC_EMR = 0xF1, (t)->TC_TCR = 1)
+#define StopCounter(t)  ((t)->TC_EMR = 0, (t)->TC_TCR = 2)
+
+void InitBuzzer(void) {
+
+  chEvtInit(&BuzzerSilentEventSource);
+
+  /*
+   * Switches P0.12 and P0.13 to MAT1.0 and MAT1.1 functions.
+   * Enables Timer1 clock.
+   */
+  PINSEL0 &= 0xF0FFFFFF;
+  PINSEL0 |= 0x0A000000;
+  PCONP = (PCONP & PCALL) | PCTIM1;
+
+  /*
+   * Timer setup.
+   */
+  TC *tc = T1Base;
+  StopCounter(tc);
+  tc->TC_CTCR = 0;                      // Clock source is PCLK.
+  tc->TC_PR = 0;                        // Prescaler disabled.
+  tc->TC_MCR = 2;                       // Clear TC on match MR0.
+}
+
+static void stop(void *p) {
+  TC *tc = T1Base;
+
+  StopCounter(tc);
+  chEvtSendI(&BuzzerSilentEventSource);
+}
+
+void PlaySound(int freq, t_time duration) {
+  static VirtualTimer bvt;
+  TC *tc = T1Base;
+
+  chSysLock();
+
+  if (bvt.vt_func) {                    // If a sound is already being played
+    chVTResetI(&bvt);                   // then aborts it.
+    StopCounter(tc);
+  }
+
+  tc->TC_MR0 = tc->TC_MR1 = (PCLK / (freq * 2));
+  StartCounter(tc);
+  chVTSetI(&bvt, duration, stop, NULL);
+
+  chSysUnlock();
+}