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RobTillaartRobTillaart
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fix ESP compile failure
added flags & error messages added MIT license refactor
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-61
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‎sketches/DHT_Simulator/DHT_Simulator.ino‎

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Original file line numberDiff line numberDiff line change
@@ -1,22 +1,48 @@
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//
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// FILE: DHT_simulator.ino
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// AUTHOR: Rob Tillaart
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// VERSION: 0.1.01
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// PURPOSE:
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// VERSION: 0.2.0
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// PURPOSE: Simulation of the DHT protocol
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// DATE: 2014-06-14
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// URL:
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//
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// Released to the public domain
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//
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// URL: https://github.com/RobTillaart/DHT_Simulator
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// TODO
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// - robustness
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// - timeout loops
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// - simulate CRC errors
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// - simulate timeout error
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// - simulate pulselength error (single bit)
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// - split loop into some functions?
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// SET ACTUAL PINS PER PLATFORM
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const int dataPin = 5; // connect to MCU ( !! also connect GND !! )
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#if defined(__AVR__)
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const int humPin = A0; // analog pins for potmeters.
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const int tempPin = A2;
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#elif defined(ESP32)
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const int humPin = 14;
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const int tempPin = 15;
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#elif defined(ESP8266)
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const int humPin = 2;
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const int tempPin = 3;
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#endif
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const int dataPin = 5;
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byte b[5];
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void setup()
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// DATA TO SEND
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byte b[5]; // actual bytes sent
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int humidity; // humidity * 10 - prevent float operations
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int temperature; // temperature * 10
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// CONFIGURE
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const bool randomize = true; // use random generator
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const bool debug = false; // test data generation
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uint32_t count = 0; // count values per second generated
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uint32_t lastTime = 0; // keep track of timing
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/////////////////////////////////////////
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void setup()
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{
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Serial.begin(115200);
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Serial.print("Start ");
@@ -25,48 +51,84 @@ void setup()
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pinMode(dataPin, INPUT_PULLUP);
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}
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void loop()
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void loop()
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{
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// T = -200 .. 1800
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analogRead(A2);
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int T = analogRead(A2) * 2 - 200;
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// H = 0 .. 1000
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analogRead(A0);
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int H = analogRead(A0);
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if (H > 1000)
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yield(); // keep ESP happy
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count++;
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uint32_t now = millis();
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if (now - lastTime >= 1000)
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{
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H = 1000;
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uint32_t nps = round((1000.0 * count) / (now - lastTime));
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Serial.print("DATA PER SECOND: ");
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Serial.println(nps);
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lastTime = now;
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count = 0;
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}
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if (randomize)
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{
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humidity = random(20, 1000);
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temperature = random(-200, 1800);
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}
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else
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{
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analogRead(humPin);
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humidity = analogRead(humPin);
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analogRead(tempPin);
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temperature = analogRead(tempPin) * 2 - 200;
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}
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humidity = constrain(humidity, 0, 1000);
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temperature = constrain(temperature, -200, 1800);
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if (debug)
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{
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Serial.print(humidity);
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Serial.print("\t");
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Serial.print(temperature);
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Serial.println();
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}
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// Serial.print(H);
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// Serial.print("\t");
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// Serial.println(T);
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// WAKE UP SIGNAL DETECTED
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if (digitalRead(dataPin) == LOW)
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if (digitalRead(dataPin) == LOW)
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{
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uint32_t start = micros();
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// wait until signal goes high
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// todo timeout on blocking loop
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// wait max 1500 us until signal goes high
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while (digitalRead(dataPin) == LOW)
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{
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if (micros() - start > 1500) return;
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if (micros() - start > 1500)
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{
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// Serial.println("ERROR: low puise too long");
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return;
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}
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}
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if (micros() - start > 500) // serious request...
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if (micros() - start > 500) // serious request...
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{
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DHTsend(H, T);
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DHTsend(humidity, temperature);
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Serial.print(H);
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Serial.print(humidity);
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Serial.print("\t");
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Serial.println(T);
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Serial.print(temperature);
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Serial.print("\t");
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for (int i = 0; i < 5; i++)
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{
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if (b[i] < 0x10) Serial.print('0');
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Serial.print(b[i], HEX);
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Serial.print(' ');
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}
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Serial.println();
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}
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else
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{
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Serial.println("ERROR: low puise too short");
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}
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}
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}
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void DHTsend(int H, int T)
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{
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pinMode(dataPin, OUTPUT);
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pinMode(dataPin, OUTPUT);
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// SEND ACK
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digitalWrite(dataPin, LOW);
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delayMicroseconds(80); // 80 us
@@ -78,7 +140,7 @@ void DHTsend(int H, int T)
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b[1] = H & 255;
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b[2] = 0;
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if (T < 0)
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if (T < 0)
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{
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T = -T;
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b[2] = 0x80;
@@ -99,21 +161,13 @@ void DHTsend(int H, int T)
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digitalWrite(dataPin, LOW);
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delayMicroseconds(50); // 50 us
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pinMode(dataPin, INPUT_PULLUP);
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// DEBUG
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// for (int i = 0; i < 5; i++)
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// {
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// Serial.print(b[i]);
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// Serial.print(" ");
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// }
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// Serial.println();
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}
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// timing manual tuned
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void DHTsendbyte(byte b)
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{
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byte mask = 128;
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for(int i = 0; i < 8; i++)
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for (int i = 0; i < 8; i++)
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{
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digitalWrite(dataPin, LOW);
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delayMicroseconds(45); // 50 us
@@ -124,21 +178,4 @@ void DHTsendbyte(byte b)
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}
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}
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// -- END OF FILE --

‎sketches/DHT_Simulator/LICENSE‎

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MIT License
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Copyright (c) 2014-2020 Rob Tillaart
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.

‎sketches/DHT_Simulator/README.md‎

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# DHT_Simulator
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Arduino sketch to simulate a DHT22
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## Description
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The DHT22 is an often used sensor and many libraries are written for it
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including my own DHTNEW library. To better understand the protocol and
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to be able to debug my library I wrote a simulator for the DHT sensors
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in 2014.
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The simulator can be used to test applications to that use a DHT sensor,
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e.g. to get high alarm temp or whatever.
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Currently the code uses two analog ports to get some value for temperature
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and humidity. Just connect two potmeters to play and simulate increase and
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decrease of the temperature and humidity.
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## 0.2.0 version
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- added flag for random generation of data
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- added flag for debug
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- explicit support ESP32 & ESP8266
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- added counter # samples generated per second ==> so one sees it still runs
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- added error and debug messages // some commented
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The simulator is not tested extensively so please report bugs.
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## Future
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Idea is to use the code of the simulator in combination with a
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Senserion or two separate sensors (DS18B20 + ? ) to provide an
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accurate temperature and humidity. These could then be readable
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with any DHT library with the performance of a DHT (~ 5ms).
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(when time permits)
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## Operation
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- adjust the pins in the head of the program to meet your setup
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- compile, connect, run
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And have fun.

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