From 72b6c699d355fcd41addb9919d846e63105b9db7 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Mon, 13 May 2013 22:34:19 -0700 Subject: altos: Add debounce helper. Use in button and quadrature drivers for TeleLCO Signed-off-by: Keith Packard --- src/core/ao_debounce.h | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 src/core/ao_debounce.h (limited to 'src/core') diff --git a/src/core/ao_debounce.h b/src/core/ao_debounce.h new file mode 100644 index 00000000..ebe290e1 --- /dev/null +++ b/src/core/ao_debounce.h @@ -0,0 +1,52 @@ +/* + * Copyright © 2013 Keith Packard + * + * 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. + */ + +#ifndef _AO_DEBOUNCE_H_ +#define _AO_DEBOUNCE_H_ + +struct ao_debounce { + struct ao_debounce *next; + + /* time that pin value must be stable before accepting */ + int8_t hold; + + /* last value reported to app; don't report it twice */ + uint8_t value; + + /* current count of intervals pin value has been stable */ + int8_t count; + + /* This pin is running */ + uint8_t running; + + /* Get the current pin value */ + uint8_t (*_get)(struct ao_debounce *debounce); + + /* The stable value has changed */ + void (*_set)(struct ao_debounce *debounce, uint8_t value); +}; + +void +_ao_debounce_start(struct ao_debounce *debounce); + +void +_ao_debounce_stop(struct ao_debounce *debounce); + +void +ao_debounce_init(void); + +#endif /* _AO_DEBOUNCE_H_ */ -- cgit v1.2.3