Temperature sensor

esp32test/Esp32DeepSleepTest/include/DS18B20.h

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+/**
+ * @file DS18B20.h
+ * @author your name (you@domain.com)
+ * @brief 
+ * @version 0.1
+ * @date 2020-06-09
+ * 
+ * @copyright Copyright (c) 2020
+ * Based on the LUA code from the ESP8266
+ * --------------------------------------------------------------------------------
+ * -- DS18B20 one wire module for NODEMCU
+ * -- NODEMCU TEAM
+ * -- LICENCE: http://opensource.org/licenses/MIT
+ * -- Vowstar <vowstar@nodemcu.com>
+ * -- 2015/02/14 sza2 <sza2trash@gmail.com> Fix for negative values
+ * --------------------------------------------------------------------------------
+ */
+
+#ifndef DS18B20_H
+#define DS18B20_H
+
+#include <OneWire.h>
+
+class Ds18B20 {
+    private:
+        OneWire* mDs;
+        int foundDevices;
+    public:
+        Ds18B20(int pin) {
+            this->mDs = new OneWire(pin);
+        }
+
+        ~Ds18B20() {
+            delete this->mDs;
+        }
+        /**
+         * @brief read amount sensots
+         * check for available of DS18B20 sensors
+         * @return amount of sensors
+         */
+        int readDevices(void);
+
+        /**
+         * @brief Read all temperatures in celsius
+         * 
+         * @param pTemperatures     array of float valuies
+         * @param maxTemperatures  size of the given array
+         * @return int amount of read temperature values
+         */
+        int readAllTemperatures(float* pTemperatures, int maxTemperatures);
+};
+#endif

esp32test/Esp32DeepSleepTest/src/DS18B20.cpp

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+/**
+ * @file DS18B20.cpp
+ * @author your name (you@domain.com)
+ * @brief 
+ * @version 0.1
+ * @date 2020-06-09
+ * 
+ * @copyright Copyright (c) 2020
+ * 
+ */
+
+#include "DS18B20.h"
+
+#define STARTCONV       0x44
+#define READSCRATCH     0xBE  // Read EEPROM
+#define TEMP_LSB        0
+#define TEMP_MSB        1
+#define SCRATCHPADSIZE  9
+#define OFFSET_CRC8     8       /**< 9th byte has the CRC of the complete data */
+
+//Printf debugging
+//#define DS_DEBUG
+
+int Ds18B20::readDevices() {
+    byte addr[8];
+
+    int amount = -1;
+    while (this->mDs->search(addr)) {
+        amount++;
+    }
+    this->mDs->reset_search();
+    return amount;
+}
+
+int Ds18B20::readAllTemperatures(float* pTemperatures, int maxTemperatures) {
+    byte addr[8];
+    uint8_t scratchPad[SCRATCHPADSIZE];
+    int currentTemp = 0;
+
+    while (this->mDs->search(addr)) {
+#ifdef DS_DEBUG
+        Serial.print(" ROM =");
+        for (i = 0; i < 8; i++) {
+            Serial.write(' ');
+            Serial.print(addr[i], HEX);
+        }
+#endif
+        this->mDs->reset();
+        this->mDs->select(addr);
+        this->mDs->write(STARTCONV);
+        this->mDs->reset();
+        this->mDs->select(addr);
+        this->mDs->write(READSCRATCH);
+
+        // Read all registers in a simple loop
+        // byte 0: temperature LSB
+        // byte 1: temperature MSB
+        // byte 2: high alarm temp
+        // byte 3: low alarm temp
+        // byte 4: DS18S20: store for crc
+        //         DS18B20 & DS1822: configuration register
+        // byte 5: internal use & crc
+        // byte 6: DS18S20: COUNT_REMAIN
+        //         DS18B20 & DS1822: store for crc
+        // byte 7: DS18S20: COUNT_PER_C
+        //         DS18B20 & DS1822: store for crc
+        // byte 8: SCRATCHPAD_CRC
+#ifdef DS_DEBUG
+        Serial.write("\r\nDATA:");
+        for (uint8_t i = 0; i < 9; i++) {
+            Serial.print(scratchPad[i], HEX);
+        }
+#else
+        delay(50);
+#endif
+        for (uint8_t i = 0; i < 9; i++) {
+            scratchPad[i] = this->mDs->read();
+        }
+        uint8_t crc8 = this->mDs->crc8(scratchPad, 8);
+
+        /* Only work an valid data */
+        if (crc8 == scratchPad[OFFSET_CRC8]) {
+            int16_t fpTemperature = (((int16_t) scratchPad[TEMP_MSB]) << 11)
+                | (((int16_t) scratchPad[TEMP_LSB]) << 3);
+            float celsius =  (float) fpTemperature * 0.0078125;
+#ifdef DS_DEBUG
+            Serial.printf("\r\nTemp%d %f °C (Raw: %d, %x =? %x)\r\n", (currentTemp+1), celsius, fpTemperature, crc8, scratchPad[8]);
+#endif
+            /* check, if the buffer as some space for our data */
+            if (currentTemp < maxTemperatures) {
+                pTemperatures[currentTemp] = celsius;
+            } else {
+                return -1;
+            }
+        }
+        currentTemp++;
+    } 
+    this->mDs->reset();
+#ifdef DS_DEBUG
+    Serial.println(" No more addresses.");
+    Serial.println();
+#endif
+
+    return currentTemp;
+}