====== Test Page ====== ==== Image Map ==== Disadvantage: when the image is rescaled, the image map is not. So the hot spots with the links are not where they are supposed to be. DHT-22 DS18B20 DS18B20 ESP32 PV and Battery Level ESP32CAM Pond ==== Relative Positions (for smartphones etc.) ==== Advantage: position of the hot spots scales with the size of the image displayed.
==== Lists ====

Testing Lists with HTML

As mentioned before, the data that is transmitted consists of 40 bits. 2 bytes for the relative humidity, 2 bytes for the temperature and 1 byte (check-sum) to check for finding errors in the transmission. The principle becomes clearer when looking at an example transmission:
\[\mathrm{0000\; 0010\; 1000\; 1100\;\; 0000\; 0001\; 0101\; 1111\;\; 1110\; 1110}\] \[\mathrm{\;\;\;\;\;\;\;\;\; Humidity \;\;\;\;\;\;\;\;\;|\;\;\;\;\;Temperature \;\;\;\;\;\;\;|\; check-sum}\]

  1. The first two bytes contain the relative humidity data, converted to decimal, that gives:
    \[\mathrm{0000\; 0010\;\; 1000\; 1100_{2}} → 652_{10}\] To obtain the relative humidity RH in percent, the value must be divided by 10:
    \[RH = \frac{\mathrm{652}}{\mathrm{10}} = \mathrm{65.2\;\%}\]
  2. For the temperature it works in a similar way. The binary gets converted to decimal and is divided by 10 to obtain the temperature in °C:
    \[\mathrm{0000\; 0001\;\; 0101\; 1111_2 → 351_{10}}\] \[T = \mathrm{\frac{351}{10} = 35.1 °C}\] Unlike relative humidity, the temperature can be below 0 (negative). If that is the case, the first digit of the first temperature byte (byte 3) is a 1.

  3. The last byte contains the 8 least significant bits (LSB) of the sum of both humidity and both temperature bytes:
    \[\mathrm{0000\; 0010 + 1000\; 1100 + 0000\; 0001 + 0101\; 1111 = 1110\; 1110}\] After receiving the data, if the last byte (check-sum) is different from the 8 LSBs of the sum of the other 4 bytes, there was an error in the transmission. The MCU can thus check if the data was transmitted correctly.
==== Changing Fonts and Colours in the text ==== The function Serial.begin() starts the serial connection. Arduino IDE style Fonts for functions etc: === Reoccurring Functions, Templates === InlineText bold TextInCourierNew TextInOrange Black: TextInBlack Orange: TextInOrange Blue: TextInBlue Green: TextInGreen Hexadecimal Color Codes: Orange (Objects, functions): #CD5307 Blue (Variables): #0098A3 Green (preprocessor commands): #5A6B0F Basic: Text **Methods** Class.method() \\ Class.method() \\ Class.method() **Loops and control structures** \\ for() \\ if() \\ setup() \\ loop() **Variables** const int \\ String \\ long \\ unsigned int \\ uint8_t **Preprocessor Commands** #include \\ #define Functions delay() \\ printAddress() ===== Links ===== ↩ Back to the main page
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Main Page Sensors Default Link Color RGB: #2E71B8
===== Materials and Methods ===== ==== Sensors and modules that are used ==== Further information on the sensors and devices used can be seen in their respective pages: **[[dht22|DHT-22 Air Temperature and Humidity Sensor]]** **[[ds18b20|DS18B20 Waterproof Temperature Sensor]]** **[[SN74HC595N|SN74HC595(N) Shift Register]]** **[[DS3231RTC|DS3231 Real Time Clock]]** ==== Programming Deep Sleep and MQTT ==== **[[amc2020:group_n:deepsleep|ESP32 Deep Sleep]]** **[[amc2020:group_n:wifi|Testing Wifi and MQTT]]** ==== Setup of the ESP32 and the Modules ==== ^{{:amc2020:group_n:esp32_sensors_rtc_pn2222.png?direct&500|Figure 2}}^ |**//Figure 2//** Graphic on how to set up the ESP32 and the modules and parts.| ^{{:amc2020:group_n:esp32_wiring.png?direct&800|Figure 3}}^ |**//Figure 3//** Schematic of the connections between ESP32 and the modules and parts.| ===== Results ===== ^ {{:amc2020:group_n:pond_monitoring_station_data_logger_graphana_light_theme.png?800&direct|Figure 4}} ^ | **//Figure 4//** Measurement results of the DHT-22 and DS18B20 sensors visualized in Grafana. | {{:amc2020:group_n:pond.jpg?direct&800|}}