382 lines
8.6 KiB
C
382 lines
8.6 KiB
C
/*
|
|
* Copyright (c) 2007, 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 ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* @(#)$Id: sht11.c,v 1.3 2008/11/10 21:10:36 adamdunkels Exp $
|
|
*/
|
|
|
|
/*
|
|
* Device driver for the Sensirion SHT1x/SHT7x family of humidity and
|
|
* temperature sensors.
|
|
*/
|
|
|
|
#include "contiki.h"
|
|
#include <stdio.h>
|
|
#include <dev/sht11.h>
|
|
#include "sht11-arch.h"
|
|
|
|
#define DEBUG 0
|
|
|
|
#if DEBUG
|
|
#include <stdio.h>
|
|
#define PRINTF(...) printf(__VA_ARGS__)
|
|
#else
|
|
#define PRINTF(...)
|
|
#endif
|
|
|
|
#ifndef SDA_0
|
|
#define SDA_0() (SHT11_PxDIR |= BV(SHT11_ARCH_SDA)) /* SDA Output=0 */
|
|
#define SDA_1() (SHT11_PxDIR &= ~BV(SHT11_ARCH_SDA)) /* SDA Input */
|
|
#define SDA_IS_1 (SHT11_PxIN & BV(SHT11_ARCH_SDA))
|
|
|
|
#define SCL_0() (SHT11_PxOUT &= ~BV(SHT11_ARCH_SCL)) /* SCL Output=0 */
|
|
#define SCL_1() (SHT11_PxOUT |= BV(SHT11_ARCH_SCL)) /* SCL Output=1 */
|
|
#endif
|
|
/* adr command r/w */
|
|
#define STATUS_REG_W 0x06 /* 000 0011 0 */
|
|
#define STATUS_REG_R 0x07 /* 000 0011 1 */
|
|
#define MEASURE_TEMP 0x03 /* 000 0001 1 */
|
|
#define MEASURE_HUMI 0x05 /* 000 0010 1 */
|
|
#define RESET 0x1e /* 000 1111 0 */
|
|
|
|
/* This can probably be reduced to 250ns according to data sheet. */
|
|
#ifndef delay_400ns
|
|
#define delay_400ns() _NOP()
|
|
#endif
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
sstart(void)
|
|
{
|
|
SDA_1(); SCL_0();
|
|
delay_400ns();
|
|
SCL_1();
|
|
delay_400ns();
|
|
SDA_0();
|
|
delay_400ns();
|
|
SCL_0();
|
|
delay_400ns();
|
|
SCL_1();
|
|
delay_400ns();
|
|
SDA_1();
|
|
delay_400ns();
|
|
SCL_0();
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
sreset(void)
|
|
{
|
|
int i;
|
|
SDA_1();
|
|
SCL_0();
|
|
for(i = 0; i < 9 ; i++) {
|
|
SCL_1();
|
|
delay_400ns();
|
|
SCL_0();
|
|
delay_400ns();
|
|
}
|
|
sstart(); /* Start transmission, why??? */
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/*
|
|
* Return true if we received an ACK.
|
|
*/
|
|
static int
|
|
swrite(unsigned _c)
|
|
{
|
|
unsigned char c = _c;
|
|
int i;
|
|
int ret;
|
|
|
|
for(i = 0; i < 8; i++, c <<= 1) {
|
|
if(c & 0x80) {
|
|
SDA_1();
|
|
} else {
|
|
SDA_0();
|
|
}
|
|
SCL_1();
|
|
delay_400ns();
|
|
SCL_0();
|
|
delay_400ns();
|
|
}
|
|
|
|
SDA_1();
|
|
SCL_1();
|
|
delay_400ns();
|
|
ret = !SDA_IS_1;
|
|
|
|
SCL_0();
|
|
|
|
return ret;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
static unsigned
|
|
sread(int send_ack)
|
|
{
|
|
int i;
|
|
unsigned char c = 0x00;
|
|
|
|
SDA_1();
|
|
for(i = 0; i < 8; i++) {
|
|
c <<= 1;
|
|
SCL_1();
|
|
delay_400ns();
|
|
if(SDA_IS_1) {
|
|
c |= 0x1;
|
|
}
|
|
SCL_0();
|
|
delay_400ns();
|
|
}
|
|
|
|
if(send_ack) {
|
|
SDA_0();
|
|
}
|
|
SCL_1();
|
|
delay_400ns();
|
|
SCL_0();
|
|
|
|
SDA_1(); /* Release SDA */
|
|
|
|
return c;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
#define CRC_CHECK
|
|
#ifdef CRC_CHECK
|
|
static unsigned char
|
|
rev8bits(unsigned char v)
|
|
{
|
|
unsigned char r = v;
|
|
int s = 7;
|
|
|
|
for (v >>= 1; v; v >>= 1) {
|
|
r <<= 1;
|
|
r |= v & 1;
|
|
s--;
|
|
}
|
|
r <<= s; /* Shift when v's highest bits are zero */
|
|
return r;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/* BEWARE: Bit reversed CRC8 using polynomial ^8 + ^5 + ^4 + 1 */
|
|
static unsigned
|
|
crc8_add(unsigned acc, unsigned byte)
|
|
{
|
|
int i;
|
|
acc ^= byte;
|
|
for(i = 0; i < 8; i++) {
|
|
if(acc & 0x80) {
|
|
acc = (acc << 1) ^ 0x31;
|
|
} else {
|
|
acc <<= 1;
|
|
}
|
|
}
|
|
return acc & 0xff;
|
|
}
|
|
#endif /* CRC_CHECK */
|
|
/*---------------------------------------------------------------------------*/
|
|
/*
|
|
* Power up the device. The device can be used after an additional
|
|
* 11ms waiting time.
|
|
*/
|
|
void
|
|
sht11_init(void)
|
|
{
|
|
/*
|
|
* SCL Output={0,1}
|
|
* SDA 0: Output=0
|
|
* 1: Input and pull-up (Output=0)
|
|
*/
|
|
#ifdef SHT11_INIT
|
|
SHT11_INIT();
|
|
#else
|
|
/* As this driver is bit-bang based, disable the I2C first
|
|
This assumes the SDA/SCL pins passed in the -arch.h file are
|
|
actually the same used for I2C operation, else comment out the following
|
|
*/
|
|
#warning SHT11: DISABLING I2C BUS
|
|
SHT11_PxSEL &= ~(BV(SHT11_ARCH_SDA) | BV(SHT11_ARCH_SCL));
|
|
#if defined(__MSP430_HAS_MSP430X_CPU__) || defined(__MSP430_HAS_MSP430XV2_CPU__)
|
|
SHT11_PxREN &= ~(BV(SHT11_ARCH_SDA) | BV(SHT11_ARCH_SCL));
|
|
#endif
|
|
|
|
/* Configure SDA/SCL as GPIOs */
|
|
SHT11_PxOUT |= BV(SHT11_ARCH_PWR);
|
|
SHT11_PxOUT &= ~(BV(SHT11_ARCH_SDA) | BV(SHT11_ARCH_SCL));
|
|
SHT11_PxDIR |= BV(SHT11_ARCH_PWR) | BV(SHT11_ARCH_SCL);
|
|
#endif
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/*
|
|
* Power of device.
|
|
*/
|
|
void
|
|
sht11_off(void)
|
|
{
|
|
#ifdef SHT11_OFF
|
|
SHT11_OFF();
|
|
#else
|
|
SHT11_PxOUT &= ~BV(SHT11_ARCH_PWR);
|
|
SHT11_PxOUT &= ~(BV(SHT11_ARCH_SDA) | BV(SHT11_ARCH_SCL));
|
|
SHT11_PxDIR |= BV(SHT11_ARCH_PWR) | BV(SHT11_ARCH_SCL);
|
|
#endif
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/*
|
|
* Only commands MEASURE_HUMI or MEASURE_TEMP!
|
|
*/
|
|
static unsigned int
|
|
scmd(unsigned cmd)
|
|
{
|
|
unsigned int n;
|
|
|
|
if(cmd != MEASURE_HUMI && cmd != MEASURE_TEMP) {
|
|
PRINTF("Illegal command: %d\n", cmd);
|
|
return -1;
|
|
}
|
|
|
|
sstart(); /* Start transmission */
|
|
if(!swrite(cmd)) {
|
|
PRINTF("SHT11: scmd - swrite failed\n");
|
|
goto fail;
|
|
}
|
|
|
|
for(n = 0; n < 20000; n++) {
|
|
if(!SDA_IS_1) {
|
|
unsigned t0, t1, rcrc;
|
|
t0 = sread(1);
|
|
t1 = sread(1);
|
|
rcrc = sread(0);
|
|
PRINTF("SHT11: scmd - read %d, %d\n", t0, t1);
|
|
#ifdef CRC_CHECK
|
|
{
|
|
unsigned crc;
|
|
crc = crc8_add(0x0, cmd);
|
|
crc = crc8_add(crc, t0);
|
|
crc = crc8_add(crc, t1);
|
|
if(crc != rev8bits(rcrc)) {
|
|
PRINTF("SHT11: scmd - crc check failed %d vs %d\n",
|
|
crc, rev8bits(rcrc));
|
|
goto fail;
|
|
}
|
|
}
|
|
#endif
|
|
return (t0 << 8) | t1;
|
|
}
|
|
/* short wait before next loop */
|
|
clock_wait(1);
|
|
}
|
|
fail:
|
|
sreset();
|
|
return -1;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/*
|
|
* Call may take up to 210ms.
|
|
*/
|
|
unsigned int
|
|
sht11_temp(void)
|
|
{
|
|
return scmd(MEASURE_TEMP);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/*
|
|
* Call may take up to 210ms.
|
|
*/
|
|
unsigned int
|
|
sht11_humidity(void)
|
|
{
|
|
return scmd(MEASURE_HUMI);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
#if 1 /* But ok! */
|
|
unsigned
|
|
sht11_sreg(void)
|
|
{
|
|
unsigned sreg, rcrc;
|
|
|
|
sstart(); /* Start transmission */
|
|
if(!swrite(STATUS_REG_R)) {
|
|
goto fail;
|
|
}
|
|
|
|
sreg = sread(1);
|
|
rcrc = sread(0);
|
|
|
|
#ifdef CRC_CHECK
|
|
{
|
|
unsigned crc;
|
|
crc = crc8_add(0x0, STATUS_REG_R);
|
|
crc = crc8_add(crc, sreg);
|
|
if (crc != rev8bits(rcrc))
|
|
goto fail;
|
|
}
|
|
#endif
|
|
|
|
return sreg;
|
|
|
|
fail:
|
|
sreset();
|
|
return -1;
|
|
}
|
|
#endif
|
|
/*---------------------------------------------------------------------------*/
|
|
#if 0
|
|
int
|
|
sht11_set_sreg(unsigned sreg)
|
|
{
|
|
sstart(); /* Start transmission */
|
|
if(!swrite(STATUS_REG_W)) {
|
|
goto fail;
|
|
}
|
|
if(!swrite(sreg)) {
|
|
goto fail;
|
|
}
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
sreset();
|
|
return -1;
|
|
}
|
|
#endif
|
|
/*---------------------------------------------------------------------------*/
|
|
#if 0
|
|
int
|
|
sht11_reset(void)
|
|
{
|
|
sstart(); /* Start transmission */
|
|
if(!swrite(RESET)) {
|
|
goto fail;
|
|
}
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
sreset();
|
|
return -1;
|
|
}
|
|
#endif
|
|
/*---------------------------------------------------------------------------*/
|