Added documentation

README.md

@@ -1,3 +1,92 @@
-# DS18B20_cpp
-
-This is small installable c++ library for raspverry pi to communicate with a DS18B20 temperature sensor.
+# DS18B20_cpp
+
+This is small installable c++ library for raspverry pi (or other single board computers) to communicate with a DS18B20 temperature sensor.
+
+## Usage
+
+```cpp
+void test()
+{
+    // Set GPIO connected to sensors one-Wire interface to input with PullUp resistor
+    // In this example, the bcm2835 library is used, but all other libraries are also good
+    bcm2835_gpio_fsel(4, BCM2835_GPIO_FSEL_INPT);
+    bcm2835_gpio_set_pud(4, BCM2835_GPIO_PUD_UP);
+
+    // Connect to sensor by creating a new DS18B20 object
+    // Give the sensors HW address as parameter in the constructor
+    // You can get the HW address of connected one-Wire devices via folder names in /sys/bus/w1/devices/
+    DS18B20 ds18b20 {"28-3c01d6076edb"}
+
+    // Alternatively you can tell the system to search for a connected sensor
+    // Please notice that this method can only find ONE sensor,
+    // if you want to connect multible DS18B20 sensors, please specify the HW addresses as shown above
+    DS18B20 ds18b20_alt;
+
+    // Read the current temperature with one simple method call
+    // The temperature unit is degrees Celsius and the datatype is float
+    float currentTemp = ds18b20.readTemp();
+}
+```
+
+## Installation
+
+This library can be installed this way:
+
+1. Clone git repository
+1. Create Makefile to compile code
+1. Compile code locally
+1. Install library by copying the code to library folder
+
+```console
+<go to your favourite folder to clone into>
+git clone https://github.com/nilshenrich/DS18B20_cpp.git DS18B20_cpp
+cd DS18B20_cpp
+mkdir build
+cd build/
+cmake ..
+make
+sudo make install
+```
+
+To run test programm, go to repositorys root folder and run compileTest.sh:
+```console
+./compileTest.sh
+```
+
+After compiling has finished successfully, a binary file has been created in build folder you can execute:
+```console
+cd build/
+./DS18B20
+```
+
+Now the include file ds18b20.h lies in /usr/local/include\
+and the lib files lie in /usr/local/lib
+
+### Error help
+
+If you get a compiler error because not found include files in you project that uses this DS18B20 library, adding the compiler search path "/usr/local/include" may fix it.\
+If you get a linker error, adding the linker search path "/usr/local/lib" and the linker flag "-lds18b20" may fix it.
+
+If you get a runtime error like this:
+```
+error while loading shared libraries: libds18b20.so.1: cannot open shared object file: No such file or directory
+```
+runnig this command can solve it:
+```console
+sudo /sbin/ldconfig -v
+```
+
+[See link](https://itsfoss.com/solve-open-shared-object-file-quick-tip/)
+
+## Needed packages
+
+To run the installation process properly, some packages must be preinstalled on your system.\
+This installation guide is for debian based distributions. If you run another operating system, please see specific documentation for package installation on the internet.
+
+1. build-essential (Contains the needed C/C++ compiler)
+1. cmake
+
+```console
+sudo apt install build-essential
+sudo apt install cmake
+```