Science 2022 - Polling Sensors - Temperature and RH

CMakeLists.txt

@@ -114,6 +114,7 @@ add_app_subdirectory(${TEST_APPS_DIR}/test-pwm)
 add_app_subdirectory(${TEST_APPS_DIR}/test-pwmin)
 add_app_subdirectory(${TEST_APPS_DIR}/test-quadrature64cpr)
 add_app_subdirectory(${TEST_APPS_DIR}/test-stress-can)
+add_app_subdirectory(${TEST_APPS_DIR}/test-temp-RH)
 add_app_subdirectory(${TEST_APPS_DIR}/test-units)
 add_app_subdirectory(${TEST_APPS_DIR}/test-watchdog)
 

libs/sensors/CMakeLists.txt

@@ -21,6 +21,16 @@ target_link_libraries(CurrentSensor
         Sensor
         mbed-os
         )
+
+add_library(DHT22 STATIC)
+target_sources(DHT22 PRIVATE src/DHT22.cpp)
+target_include_directories(DHT22 PUBLIC include)
+target_link_libraries(DHT22
+        PRIVATE
+        Sensor
+        mbed-os
+        )
+
 add_library(PollingSensors STATIC)
 target_sources(PollingSensors PRIVATE src/PollingSensors.cpp)
 target_include_directories(PollingSensors PUBLIC include)
@@ -30,4 +40,3 @@ target_link_libraries(PollingSensors
         mbed-os
         Logger
         )
-

libs/sensors/include/DHT22.h

@@ -0,0 +1,61 @@
+/*
+ *  DHT Library for  Digital-output Humidity and Temperature sensors
+ *
+ *  Works with DHT11, DHT21, DHT22
+ *             SEN11301P,  Grove - Temperature&Humidity Sensor     (Seeed Studio)
+ *             SEN51035P,  Grove - Temperature&Humidity Sensor Pro (Seeed Studio)
+ *             AM2302   ,  temperature-humidity sensor
+ *             RHT01,RHT02, RHT03    ,  Humidity and Temperature Sensor         (Sparkfun)
+ *
+ *  Copyright (C) Wim De Roeve
+ *                based on DHT22 sensor library by HO WING KIT
+ *                Arduino DHT11 library
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documnetation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to  whom the Software is
+ * furished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS OR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This code has been modified to work with the sensor module
+ */
+
+#pragma once
+
+#include "Sensor.h"
+#include "mbed.h"
+
+namespace Sensor {
+class DHT final : public Sensor {
+ public:
+  DHT(PinName pin);
+  ~DHT();
+  [[nodiscard]] bool reset() override;
+  [[nodiscard]] bool update(void);
+  float read(void) override;
+  float alternateRead(void) override;
+  bool getStatus() const override;
+
+ private:
+  time_t _lastReadTime;
+  float _lastTemperature;
+  float _lastHumidity;
+  PinName _pin;
+  bool _firsttime;
+  int DHT_data[6];
+  float CalcTemperature();
+  float CalcHumidity();
+};
+}  // namespace Sensor

libs/sensors/src/DHT22.cpp

@@ -0,0 +1,195 @@
+/*
+ *  DHT Library for  Digital-output Humidity and Temperature sensors
+ *
+ *  Works with DHT11, DHT22
+ *             SEN11301P,  Grove - Temperature&Humidity Sensor     (Seeed Studio)
+ *             SEN51035P,  Grove - Temperature&Humidity Sensor Pro (Seeed Studio)
+ *             AM2302   ,  temperature-humidity sensor
+ *             HM2303   ,  Digital-output humidity and temperature sensor
+ *
+ *  Copyright (C) Wim De Roeve
+ *                based on DHT22 sensor library by HO WING KIT
+ *                Arduino DHT11 library
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documnetation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to  whom the Software is
+ * furished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS OR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This code has been modified to work with the sensor module
+ */
+
+#include "DHT22.h"
+
+#define DHT_DATA_BIT_COUNT 41
+
+using namespace Sensor;
+
+DHT::DHT(PinName pin) {
+  _pin       = pin;
+  _firsttime = true;
+}
+
+DHT::~DHT() {}
+
+// Reads temparature and relative humidity data from sensor, saves it in corresponding variables
+bool DHT::update() {
+  int i, j, retryCount, b;
+  unsigned int bitTimes[DHT_DATA_BIT_COUNT];
+
+  time_t currentTime = time(NULL);
+
+  DigitalInOut DHT_io(_pin);
+
+  for (i = 0; i < DHT_DATA_BIT_COUNT; i++) {
+    bitTimes[i] = 0;
+  }
+
+  // Only asks for data if more than 2 seconds has lapsed since last call
+  if (!_firsttime) {
+    if (int(currentTime - _lastReadTime) < 2) {
+      // printf("Too Fast!");
+      return false;
+    }
+  } else {
+    _firsttime    = false;
+    _lastReadTime = currentTime;
+  }
+  retryCount = 0;
+
+  do {
+    if (retryCount > 125) {
+      // printf("Bus Busy");
+      return false;
+    }
+    retryCount++;
+    wait_us(2);
+  } while ((DHT_io == 0));
+
+  // Send start signal
+  DHT_io.output();
+  DHT_io = 0;
+  wait_us(18000);
+  DHT_io = 1;
+  wait_us(40);
+  DHT_io.input();
+
+  // Fails if sensor doesn't pull down data bus
+  retryCount = 0;
+  do {
+    if (retryCount > 40) {
+      // printf("No Response from sensor");
+      return false;
+    }
+    retryCount++;
+    wait_us(1);
+  } while ((DHT_io == 1));
+
+  // Sensor pulls down for 80us
+  wait_us(80);
+
+  // Gather data from sensor
+  for (i = 0; i < 5; i++) {
+    for (j = 0; j < 8; j++) {
+      retryCount = 0;
+      do {
+        if (retryCount > 75) {
+          // printf("Data Timeout");
+          return false;
+        }
+        retryCount++;
+        wait_us(1);
+      } while (DHT_io == 0);
+
+      wait_us(40);
+
+      bitTimes[i * 8 + j] = DHT_io;
+
+      int count = 0;
+      while (DHT_io == 1 && count < 100) {
+        wait_us(1);
+        count++;
+      }
+    }
+  }
+  DHT_io.output();
+  DHT_io = 1;
+
+  // Populate DHT_data byte array with bit data
+  for (i = 0; i < 5; i++) {
+    b = 0;
+    for (j = 0; j < 8; j++) {
+      if (bitTimes[i * 8 + j + 1] > 0) {
+        b |= (1 << (7 - j));
+      }
+    }
+    DHT_data[i] = b;
+  }
+
+  if (DHT_data[4] == ((DHT_data[0] + DHT_data[1] + DHT_data[2] + DHT_data[3]) & 0xFF)) {
+    _lastReadTime    = currentTime;
+    _lastTemperature = CalcTemperature();
+    _lastHumidity    = CalcHumidity();
+
+  } else {
+    // printf("Checksum failed");
+    return false;
+  }
+
+  return true;
+}
+
+// Map the temperature data from the sensor and return the mapped value
+float DHT::CalcTemperature() {
+  int v;
+
+  v = DHT_data[2] & 0x7F;
+  v *= 256;
+  v += DHT_data[3];
+  v /= 10;
+  if (DHT_data[2] & 0x80) v *= -1;
+  return float(v);
+}
+
+// Return last read humidity value
+float DHT::read() {
+  return _lastHumidity;
+}
+
+// Returns the last read temperature in the wanted scale
+float DHT::alternateRead() {
+  return _lastTemperature;
+}
+
+float DHT::CalcHumidity() {
+  int v;
+
+  v = DHT_data[0];
+  v *= 256;
+  v += DHT_data[1];
+  v /= 10;
+  return float(v);
+}
+
+// No current purpose
+bool DHT::reset() {
+  return true;
+}
+
+// No current purpose
+bool DHT::getStatus() const {
+  return true;
+}

supported_build_configurations.yaml

@@ -71,6 +71,9 @@ test-adafruitSTEMMA:
   - SCIENCE_REV2_2021
   #  - UWRT_NUCLEO
 
+test-temp-RH:
+  - UWRT_NUCLEO
+
 test-units:
   - UWRT_NUCLEO
 

test-apps/test-temp-RH/CMakeLists.txt

@@ -0,0 +1,10 @@
+add_executable(test-temp-RH)
+target_sources(test-temp-RH PRIVATE src/main.cpp)
+target_include_directories(test-temp-RH PUBLIC include)
+target_link_libraries(test-temp-RH 
+        PRIVATE 
+        DHT22 
+        Logger
+        uwrt-mars-rover-hw-bridge
+        )
+mbed_set_post_build(test-temp-RH)

test-apps/test-temp-RH/src/main.cpp

@@ -0,0 +1,23 @@
+#include "DHT22.h"
+#include "Logger.h"
+#include "PinNames.h"
+#include "mbed.h"
+
+int main() {
+  Sensor::DHT sensor(D7);
+  while (true) {
+    ThisThread::sleep_for(2000ms);
+
+    if (sensor.update()) {
+      printf("\r\nSensor data received\r\n");
+
+      ThisThread::sleep_for(1000ms);
+
+      printf("Humidity: %i\r\n", 1000 * (int)sensor.read());
+      printf("Temperature: %i\r\n", 1000 * (int)sensor.alternateRead());
+
+    } else {
+      printf("\r\nSensor reading failed\r\n");
+    }
+  }
+}