You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
113 lines
2.3 KiB
113 lines
2.3 KiB
7 years ago
|
/* Emulates a DS18B20 using a DHT22
|
||
|
|
*
|
||
|
|
* Provided by Destroyedlolo. (http://destroyedlolo.info)
|
||
|
|
*
|
||
|
|
* 23/03/2018 - First version
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <Arduino.h>
|
||
|
|
#include <LowLevel.h>
|
||
|
|
#include <OneWireSlave.h>
|
||
|
|
|
||
|
|
Pin oneWireData(2); // Where the 1-wire bus is connected to
|
||
|
|
|
||
|
|
const byte owROM[7] = { 0x28, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02 };
|
||
|
|
|
||
|
|
enum OW_Cmd {
|
||
|
|
START_CONVERSION = 0x44,
|
||
|
|
READ_SCRATCHPAD = 0xBE
|
||
|
|
};
|
||
|
|
|
||
|
|
volatile byte scratchpad[9];
|
||
|
|
|
||
|
|
/*
|
||
|
|
* DHT22 related
|
||
|
|
*/
|
||
|
|
#include <SimpleDHT.h> // https://github.com/winlinvip/SimpleDHT
|
||
|
|
|
||
|
|
SimpleDHT22 DHT;
|
||
|
|
#define pinDHT 3
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Let's go
|
||
|
|
*/
|
||
|
|
#define DEBUG // Comment out to be silence
|
||
|
|
|
||
|
|
enum DeviceState {
|
||
|
|
WAIT4RESET,
|
||
|
|
WAIT4COMMAND,
|
||
|
|
CONVERTING,
|
||
|
|
TEMPERATUREREADY
|
||
|
|
};
|
||
|
|
|
||
|
|
volatile DeviceState state = DeviceState::WAIT4RESET;
|
||
|
|
|
||
|
|
void owRcv( OneWireSlave::ReceiveEvent evt, byte cmd ){
|
||
|
|
switch( evt ){
|
||
|
|
case OneWireSlave::RE_Reset:
|
||
|
|
state = DeviceState::WAIT4COMMAND;
|
||
|
|
break;
|
||
|
|
case OneWireSlave::RE_Error:
|
||
|
|
state = DeviceState::WAIT4RESET;
|
||
|
|
break;
|
||
|
|
case OneWireSlave::RE_Byte:
|
||
|
|
switch( cmd ){
|
||
|
|
case OW_Cmd::START_CONVERSION:
|
||
|
|
state = DeviceState::CONVERTING;
|
||
|
|
OWSlave.beginWriteBit(0, true); // send zeros as long as the conversion is not finished
|
||
|
|
break;
|
||
|
|
case OW_Cmd::READ_SCRATCHPAD:
|
||
|
|
state = DeviceState::WAIT4RESET;
|
||
|
|
OWSlave.beginWrite((const byte*)scratchpad, 9, 0);
|
||
|
|
break;
|
||
|
|
#ifdef DEBUG
|
||
|
|
default:
|
||
|
|
Serial.print(F("Unknown command :"));
|
||
|
|
Serial.println( cmd, HEX );
|
||
|
|
#endif
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void setTemperature( float temp ){ // Write given temperature to the scratchpad
|
||
|
|
int16_t raw = (int16_t)(temp * 16.0f + 0.5f);
|
||
|
|
|
||
|
|
scratchpad[0] = (byte)raw;
|
||
|
|
scratchpad[1] = (byte)(raw >> 8);
|
||
|
|
scratchpad[8] = OWSlave.crc8((const byte*)scratchpad, 8);
|
||
|
|
}
|
||
|
|
|
||
|
|
void setup(){
|
||
|
|
Serial.begin(115200); // debugging
|
||
|
|
|
||
|
|
for(int i = 2; i<8; i++)
|
||
|
|
scratchpad[i] = 0;
|
||
|
|
setTemperature( 85 );
|
||
|
|
|
||
|
|
OWSlave.setReceiveCallback(&owRcv);
|
||
|
|
OWSlave.begin(owROM, oneWireData.getPinNumber());
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
void loop(){
|
||
|
|
delay(10);
|
||
|
|
|
||
|
|
if(state == DeviceState::CONVERTING){ // start conversion
|
||
|
|
float temperature = 0;
|
||
|
|
float humidite = 0;
|
||
|
|
int err;
|
||
|
|
|
||
|
|
if((err = DHT.read2(pinDHT, &temperature, &humidite, NULL)) != SimpleDHTErrSuccess){
|
||
|
|
#ifdef DEBUG
|
||
|
|
Serial.print("\nError while reading, err=");
|
||
|
|
Serial.println(err);
|
||
|
|
#endif
|
||
|
|
temperature = 85;
|
||
|
|
} else {
|
||
|
|
setTemperature( temperature );
|
||
|
|
state = DeviceState::TEMPERATUREREADY;
|
||
|
|
OWSlave.beginWriteBit(1, true);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|