https://student-wiki.eolab.de/ 2026-04-15T23:34:22+00:00 https://student-wiki.eolab.de/ https://student-wiki.eolab.de/lib/tpl/dokuwiki/images/favicon.ico text/html 2023-01-05T14:38:56+00:00 Anonymous (anonymous@undisclosed.example.com) https://student-wiki.eolab.de/doku.php?id=amc2020:group_n:deepsleep&rev=1672925936&do=diff ESP32 Deep Sleep Mode 1. About ESP32 Deep Sleep In this project the ESP32 is idle for more than 95% of the time because it is supposed to take measurements only once an hour, transmit the data and wait again. However, the ESP32 has the possibility to be run in different power modes. Besides the active mode where all peripherals are powered, there are also the modem-sleep mode, light-sleep mode, deep-sleep mode, hibernation mode and power-off mode.$\mu A$ text/html 2023-01-05T14:38:56+00:00 Anonymous (anonymous@undisclosed.example.com) https://student-wiki.eolab.de/doku.php?id=amc2020:group_n:dht22&rev=1672925936&do=diff DHT-22 Air Temperature and Humidity Sensor 1. About the Sensor Module Even though the DHT-22 is a sensor used to determine air temperature and relative humidity, what it actually measures are resistances and capacitances which are affected by temperature and humidity of the air, respectively. The DHT-22 combines two different sensors and a little circuit board in one device. The circuit board does calculations and also converts the analog output from the sensors to a digital output signal whic… text/html 2023-01-05T14:38:56+00:00 Anonymous (anonymous@undisclosed.example.com) https://student-wiki.eolab.de/doku.php?id=amc2020:group_n:ds18b20&rev=1672925936&do=diff DS18B20 Waterproof Digital Temperature Sensor 1. About the Sensor Module The DS18B20 is a digital temperature sensor chip. It is produced by Maxim Integrated Circuits and the sensor comes in different variants, for example as SMD package (Surface Mount Device) or with three pins as TO-92 package; that is a compact type of casing often used for transistors and small ICs (Integrated Circuits). There are also water-proof metal casings with a longer wire attached to it, which makes sensing in hars… text/html 2023-01-05T14:38:56+00:00 Anonymous (anonymous@undisclosed.example.com) https://student-wiki.eolab.de/doku.php?id=amc2020:group_n:ds3231rtc&rev=1672925936&do=diff DS3231 Real Time Clock 1. About the Module The DS3231 (figure 1) is a cheap but highly accurate RTC (Real Time Clock) module which communicates using I2C (Inter Integrated Circuit), which is a two-wire communication bus system. The IC includes a temperature-compensated crystal oscillator (TCXO). The module in figure 1 with the breakout pins is actually called ZS-042; the DS3231 is only the large IC at the top of the module, but both terms are used commonly.$2^{15}\mathrm{Hz}$ text/html 2023-01-05T14:38:56+00:00 Anonymous (anonymous@undisclosed.example.com) https://student-wiki.eolab.de/doku.php?id=amc2020:group_n:sn74hc595n&rev=1672925936&do=diff SN74HC595(N) Shift Register 1. About the Module As the monitoring station should be more or less self-sustainable later on, an important factor to consider is the power consumption of the devices. There are different sources of power losses that drain the batteries of the station over time. One such loss is the current that flows through the VDD pins to GND in the sensors while they are not used. This power loss could be lowered if the power supply would be just activated when the sensor is ac… text/html 2023-01-05T14:38:56+00:00 Anonymous (anonymous@undisclosed.example.com) https://student-wiki.eolab.de/doku.php?id=amc2020:group_n:start&rev=1672925936&do=diff Group N: Jonas Zender (21125) and Nepomuk Garden Pond Monitoring Station 1. Introduction In environmental monitoring different environmental parameters are measured in a systematic way to gain an insight into the processes going on in the environment. The aim is not only to better understand the complex world that surrounds us, but also to track the long-term development of for example ecosystems as it can help to register alarming trends and changes early on such that appropriate actions ca… text/html 2023-01-05T14:38:56+00:00 Anonymous (anonymous@undisclosed.example.com) https://student-wiki.eolab.de/doku.php?id=amc2020:group_n:test&rev=1672925936&do=diff 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. Relative Positions (for smartphones etc.) Advantage: position of the hot spots scales with the size of the image displayed. text/html 2023-01-05T14:38:56+00:00 Anonymous (anonymous@undisclosed.example.com) https://student-wiki.eolab.de/doku.php?id=amc2020:group_n:tutorial&rev=1672925936&do=diff Tutorial: Interactive Image in dokuwiki This is a short tutorial on how to make an image in dokuwiki interactive by implementing clickable links in different areas of the image using HTML. Below you see an image I use here as an example. I want to make three clickable areas which link to different webpages. The palm tree will link to google, the sunset to Wikipedia and the sea to YouTube. Of course, you can change the image and the links however you want. I used it in my project to make an int… text/html 2023-01-05T14:38:56+00:00 Anonymous (anonymous@undisclosed.example.com) https://student-wiki.eolab.de/doku.php?id=amc2020:group_n:wifi&rev=1672925936&do=diff ESP32 Connection to WiFi and MQTT 1. About MQTT MQTT stands for Message Queuing Telemetry Transport and is a publish-subscribe network protocol for transporting messages between different devices. It was first developed in 1999 and is very popular for IoT (Internet of Things) applications.