Install MongoDB as Windows Service

mkdir c:\data\db
mkdir c:\data\log

create a file at C:\mongodb\mongod.cfg

systemLog:
    destination: file
    path: c:\data\log\mongod.log
storage:
    dbPath: c:\data\db

Install the MongoDB service

"C:\mongodb\bin\mongod.exe" --config "C:\mongodb\mongod.cfg" --install

Start the MongoDB service

net start MongoDB

Stop or remove the MongoDB service as needed

net stop MongoDB
"C:\mongodb\bin\mongod.exe" --remove

References :
https://docs.mongodb.org/manual/tutorial/install-mongodb-on-windows/

Optocoupler

An Optocoupler, also known as an Opto-isolator or Photo-coupler, is an electronic components that interconnects two separate electrical circuits by means of a light sensitive optical interface.

Optocoupler Types
The photo-transistor and photo-darlington devices are mainly for use in DC circuits while the photo-SCR and photo-triac allow AC powered circuits to be controlled. There are many other kinds of source-sensor combinations, such as LED-photodiode, LED-LASER, lamp-photoresistor pairs, reflective and slotted optocouplers.

References :
http://www.electronics-tutorials.ws/blog/optocoupler.html

Telerik UI for Android libraries and dependencies

Add all dlls and then add the following packages using the NuGet:
Xamarin Support Library v7 AppCompat (required by the following assemblies: Chart, Feedback, Input, List & Primitives)
Xamarin Support Library v7 RecyclerView (required by the List assembly)
Xamarin Support Library v8 RenderScript (required by the Primitives assembly)

Or

The Primitives library references the Common library
The Data library references the Common library
The Input library references the Common library and v7 AppCompat
The Chart library references the Primitives, the Common libraries and v7 AppCompat
The List library references the Common, Data, v7 AppCompat and v7 RecyclerView libraries
The Feedback library references the Common librariy and v7 AppCompat

References :
http://docs.telerik.com/devtools/android/download-and-deployment/getting-started-for-xamarin
http://docs.telerik.com/devtools/android/download-and-deployment/installation-contents-and-dependencies