osd-contiki/examples/osd/climate/resources/res-ds1820.c
2014-11-26 17:12:34 +01:00

124 lines
4.5 KiB
C

/*
* Copyright (c) 2014, Nimbus Centre for Embedded Systems Research, Cork Institute of Technology.
* 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 ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*/
/**
* \file
* DS1820 Sensor Resource
*
* This is a simple GET resource that returns the temperature in Celsius
* and the humidity reading from the SHT11.
* \author
* Pablo Corbalan <paul.corbalan@gmail.com>
*/
#include "contiki.h"
#if PLATFORM_HAS_DS1820
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <math.h>
#include "rest-engine.h"
#include "dev/ds1820.h"
/* A simple getter example. Returns the reading from ds1820 sensor */
#define DS1820_TEMP_LSB 0
#define DS1820_TEMP_MSB 1
#define DS1820_COUNT_REMAIN 6
#define DS1820_COUNT_PER_C 7
//RESOURCE(ds1820, METHOD_GET, "s/temp", "title=\"Temperatur DS1820\";rt=\"temperature-c\"");
static void res_get_ds1820_handler(void *request, void *response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset);
/* A simple getter example. Returns the reading from light sensor with a simple etag */
RESOURCE(res_ds1820,
"title=\"Temperature DHTxx\";rt=\"temperature c\"",
res_get_ds1820_handler,
NULL,
NULL,
NULL);
static void
res_get_ds1820_handler(void* request, void* response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset)
{
char message[100];
int length = 0; /* |<-------->| */
union temp_raw {
int16_t s_int16;
uint16_t u_int16;
} temp_raw;
double temp_c;
int temp_integral;
int temp_centi;
unsigned int accept = -1;
REST.get_header_accept(request, &accept);
// temp = temp_read - 0.25°C + (count_per_c - count_remain) / count_per_c;
temp_raw.u_int16 = ds1820_ok[DS1820_TEMP_MSB] << 8 | ds1820_ok[DS1820_TEMP_LSB];
temp_c = temp_raw.s_int16 / 2.0
- 0.25
+ ((double) ds1820_ok[DS1820_COUNT_PER_C] - (double) ds1820_ok[DS1820_COUNT_REMAIN])
/ (double) ds1820_ok[DS1820_COUNT_PER_C];
temp_integral = (int) temp_c;
temp_centi = (int) (fabs (temp_c - (int) temp_c) * 100.0);
if(accept == -1 || accept == REST.type.TEXT_PLAIN)
{
REST.set_header_content_type(response, REST.type.TEXT_PLAIN);
snprintf(message, REST_MAX_CHUNK_SIZE, "%d.%02d C", temp_integral, temp_centi);
length = strlen(message);
memcpy(buffer, message,length );
REST.set_response_payload(response, buffer, length);
}
else if (accept == REST.type.APPLICATION_JSON)
{
REST.set_header_content_type(response, REST.type.APPLICATION_JSON);
snprintf(message, REST_MAX_CHUNK_SIZE, "{\"temp\":\"%d.%02d\"}", temp_integral, temp_centi);
length = strlen(message);
memcpy(buffer, message,length );
REST.set_response_payload(response, buffer, length);
}
else
{
REST.set_response_status(response, REST.status.NOT_ACCEPTABLE);
REST.set_response_payload(response, (uint8_t *)"Supporting content-types text/plain and application/json", 56);
}
}
#endif /* PLATFORM_HAS_DS1820 */