contiki/platform/avr-rss2/dev/battery-sensor.c
2016-02-22 20:46:07 +01:00

88 lines
2.6 KiB
C

/*
* Copyright (c) 2006, Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISE OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*
* -----------------------------------------------------------------
*
* Author : Dag Björklund, Robert Olsson
* Created : 2005-11-01
* Updated : $Date: 2010/08/25 19:30:52 $
* $Revision: 1.11 $
*/
#include "contiki.h"
#include "dev/battery-sensor.h"
#include <util/delay_basic.h>
#define delay_us(us) (_delay_loop_2(1 + (us * F_CPU) / 4000000UL))
const struct sensors_sensor battery_sensor;
/* Returns the MCU voltage in mV read from the BATMON MCU register
* See AtMega chip docs for BATMON details.
*/
static int
value(int type)
{
uint16_t mv;
int i;
/* Resolution is 75mV if V>=2.55V; and 50mV if V<=2.45V */
mv = 3675;
for(i = 0x1f; 1; i--) {
BATMON = i;
delay_us(100);
if(BATMON & 0x20) {
break;
}
if(i == 0x10) { /* Range hi or lo */
mv = 2500;
}
if(i > 0x10) {
mv -= 75;
} else {
mv -= 50;
}
}
return (int)((float)mv);
}
static int
configure(int type, int c)
{
return 0;
}
static int
status(int type)
{
return 1;
}
SENSORS_SENSOR(battery_sensor, BATTERY_SENSOR, value, configure, status);