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Fix DHTLIB bug of DHT22, DHT21, DHT33, DHT44.

This commit is contained in:
vowstar 2015-06-20 00:26:59 +08:00
parent c56659e84d
commit cda7992c1a
3 changed files with 39 additions and 25 deletions
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1
app/dhtlib/Makefile
View File

@ -42,6 +42,7 @@ INCLUDES += -I ./
INCLUDES += -I ./include
INCLUDES += -I ../include
INCLUDES += -I ../../include
INCLUDES += -I ../libc
INCLUDES += -I ../platform
PDIR := ../$(PDIR)
sinclude $(PDIR)Makefile

61
app/dhtlib/dht.c
View File

@ -29,6 +29,7 @@
#include "user_interface.h"
#include "platform.h"
#include "c_stdio.h"
#include "dht.h"
#ifndef LOW
@ -39,12 +40,12 @@
#define HIGH 1
#endif /* ifndef HIGH */
#define COMBINE_HIGH_AND_LOW_BYTE(byte_high, byte_low) ((byte_high << 8) | (byte_low))
#define COMBINE_HIGH_AND_LOW_BYTE(byte_high, byte_low) (((byte_high) << 8) | (byte_low))
static double dht_humidity;
static double dht_temperature;
static uint8_t dht_bits[5]; // buffer to receive data
static uint8_t dht_bytes[5]; // buffer to receive data
static int dht_readSensor(uint8_t pin, uint8_t wakeupDelay);
/////////////////////////////////////////////////////
@ -81,19 +82,28 @@ int dht_read_universal(uint8_t pin)
return rv; // propagate error value
}
#if defined(DHT_DEBUG_BYTES)
int i;
for (i = 0; i < 5; i++)
{
DHT_DEBUG("%02X\n", dht_bytes[i]);
}
#endif // defined(DHT_DEBUG_BYTES)
// Assume it is DHT11
// If it is DHT11, both bit[1] and bit[3] is 0
if ((dht_bits[1] == 0) && (dht_bits[3] == 0))
if ((dht_bytes[1] == 0) && (dht_bytes[3] == 0))
{
// It may DHT11
// CONVERT AND STORE
dht_humidity = dht_bits[0]; // dht_bits[1] == 0;
dht_temperature = dht_bits[2]; // dht_bits[3] == 0;
DHT_DEBUG("DHT11 method\n");
dht_humidity = dht_bytes[0]; // dht_bytes[1] == 0;
dht_temperature = dht_bytes[2]; // dht_bytes[3] == 0;
// TEST CHECKSUM
// dht_bits[1] && dht_bits[3] both 0
uint8_t sum = dht_bits[0] + dht_bits[2];
if (dht_bits[4] != sum)
// dht_bytes[1] && dht_bytes[3] both 0
uint8_t sum = dht_bytes[0] + dht_bytes[2];
if (dht_bytes[4] != sum)
{
// It may not DHT11
dht_humidity = DHTLIB_INVALID_VALUE; // invalid value, or is NaN prefered?
@ -108,16 +118,17 @@ int dht_read_universal(uint8_t pin)
// Assume it is not DHT11
// CONVERT AND STORE
dht_humidity = (double)COMBINE_HIGH_AND_LOW_BYTE(dht_bits[0], dht_bits[1]) * 0.1;
dht_temperature = (double)COMBINE_HIGH_AND_LOW_BYTE(dht_bits[2] & 0x7F, dht_bits[3]) * 0.1;
if (dht_bits[2] & 0x80) // negative dht_temperature
DHT_DEBUG("DHTxx method\n");
dht_humidity = (double)COMBINE_HIGH_AND_LOW_BYTE(dht_bytes[0], dht_bytes[1]) * 0.1;
dht_temperature = (double)COMBINE_HIGH_AND_LOW_BYTE(dht_bytes[2] & 0x7F, dht_bytes[3]) * 0.1;
if (dht_bytes[2] & 0x80) // negative dht_temperature
{
dht_temperature = -dht_temperature;
}
// TEST CHECKSUM
uint8_t sum = dht_bits[0] + dht_bits[1] + dht_bits[2] + dht_bits[3];
if (dht_bits[4] != sum)
uint8_t sum = dht_bytes[0] + dht_bytes[1] + dht_bytes[2] + dht_bytes[3];
if (dht_bytes[4] != sum)
{
return DHTLIB_ERROR_CHECKSUM;
}
@ -140,13 +151,13 @@ int dht_read11(uint8_t pin)
}
// CONVERT AND STORE
dht_humidity = dht_bits[0]; // dht_bits[1] == 0;
dht_temperature = dht_bits[2]; // dht_bits[3] == 0;
dht_humidity = dht_bytes[0]; // dht_bytes[1] == 0;
dht_temperature = dht_bytes[2]; // dht_bytes[3] == 0;
// TEST CHECKSUM
// dht_bits[1] && dht_bits[3] both 0
uint8_t sum = dht_bits[0] + dht_bits[2];
if (dht_bits[4] != sum) return DHTLIB_ERROR_CHECKSUM;
// dht_bytes[1] && dht_bytes[3] both 0
uint8_t sum = dht_bytes[0] + dht_bytes[2];
if (dht_bytes[4] != sum) return DHTLIB_ERROR_CHECKSUM;
return DHTLIB_OK;
}
@ -168,16 +179,16 @@ int dht_read(uint8_t pin)
}
// CONVERT AND STORE
dht_humidity = (double)COMBINE_HIGH_AND_LOW_BYTE(dht_bits[0], dht_bits[1]) * 0.1;
dht_temperature = (double)COMBINE_HIGH_AND_LOW_BYTE(dht_bits[2] & 0x7F, dht_bits[3]) * 0.1;
if (dht_bits[2] & 0x80) // negative dht_temperature
dht_humidity = (double)COMBINE_HIGH_AND_LOW_BYTE(dht_bytes[0], dht_bytes[1]) * 0.1;
dht_temperature = (double)COMBINE_HIGH_AND_LOW_BYTE(dht_bytes[2] & 0x7F, dht_bytes[3]) * 0.1;
if (dht_bytes[2] & 0x80) // negative dht_temperature
{
dht_temperature = -dht_temperature;
}
// TEST CHECKSUM
uint8_t sum = dht_bits[0] + dht_bits[1] + dht_bits[2] + dht_bits[3];
if (dht_bits[4] != sum)
uint8_t sum = dht_bytes[0] + dht_bytes[1] + dht_bytes[2] + dht_bytes[3];
if (dht_bytes[4] != sum)
{
return DHTLIB_ERROR_CHECKSUM;
}
@ -231,7 +242,7 @@ int dht_readSensor(uint8_t pin, uint8_t wakeupDelay)
// volatile uint8_t *PIR = portInputRegister(port);
// EMPTY BUFFER
for (i = 0; i < 5; i++) dht_bits[i] = 0;
for (i = 0; i < 5; i++) dht_bytes[i] = 0;
// REQUEST SAMPLE
// pinMode(pin, OUTPUT);
@ -283,7 +294,7 @@ int dht_readSensor(uint8_t pin, uint8_t wakeupDelay)
if ((system_get_time() - t) > 40)
{
dht_bits[idx] |= mask;
dht_bytes[idx] |= mask;
}
mask >>= 1;
if (mask == 0) // next byte?

2
app/dhtlib/dht.h
View File

@ -30,6 +30,8 @@
#define DHTLIB_DHT_WAKEUP 1
#define DHTLIB_DHT_UNI_WAKEUP 18
#define DHT_DEBUG
// max timeout is 100 usec.
// For a 16 Mhz proc 100 usec is 1600 clock cycles
// loops using DHTLIB_TIMEOUT use at least 4 clock cycli