first work on PWM input to TeleScience, 'p' command displays timer 1

[fw/altos] / src / avr / ao_pwmin.c

diff --git a/src/avr/ao_pwmin.c b/src/avr/ao_pwmin.c
new file mode 100644 (file)
index 0000000..4d96404
--- /dev/null
+++ b/src/avr/ao_pwmin.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright © 2012 Robert D. Garbee <robert@gag.com>
+ *
+ * This program 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; version 2 of the License.
+ *
+ * This program 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, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "ao.h"
+#include "ao_pwmin.h"
+
+/* 
+ * This code implements a PWM input using ICP3.  
+ *
+ * The initial use is to measure wind speed in the ULA/Ball summer intern 
+ * project payload developed at Challenger Middle School.  
+ */
+
+static void
+ao_pwmin_display(void) __reentrant
+{
+       uint8_t lo = TCNT1L; 
+       uint8_t hi = TCNT1H;
+       uint16_t value = (hi <<8) | lo;
+
+       /* now display the value we read */
+       printf("timer 1: %5u",  value);
+
+}
+
+__code struct ao_cmds ao_pwmin_cmds[] = {
+       { ao_pwmin_display,     "p\0PWM input" },
+       { 0, NULL },
+};
+
+void
+ao_pwmin_init(void)
+{
+       /* do hardware setup here */
+               /* set the spike filter bit in the TCCR3B register */
+
+       ao_cmd_register(&ao_pwmin_cmds[0]);
+}
+
+