Is it better to use arduino or microchip pic?

 the main difference between a PLC and an Arduino is their price, as the PLC usually has 100 times the price of an Αrduino. The PLC has a better processor power & memory, can handle more current in the I/O ports, the ports are optocoupled, it is more robust, it is closed architecture, it comes with industrial certificates, safety features etc.

Arduino is great platform due to this reasons:-

an open source project software and hardware 

 inexpensive

Complete board you do not need any external components to download code to it

Easy to use and learn 

Community support any question you will find support to it

And I think arduino is good platform to start with it then you cane use it to build your own project or to use stand alone avr

And even you can use the great atom platformio to program it

Arduino is better due to following reasons

1) it requires no separate code burner.

2) its memory is greater than microchip pic

3) its more user friendly & is compatible with almost all type of sensors. 

Both are very powerful and important species of microcontroller. But it will depend on the following :-

1. Your knowledge on PIC or Arduino (Choose the one you know better as a microcontroller is only as good as its programmer).

2. Make a list of your requirements(I/O Ports, ADC, I2C, USART Frequency etc) and select the appropriate chip (PIC or Arduino) based on your requirements.

For more details on choosing your microcontroller, visit the following links :-

For PIC -  http://www.pcbheaven.com/picpages/Choosing_the_right_PIC/

For Arduino - https://codeduino.com/tutorials/which-arduino-should-i-buy/

both companies have various of micro-controllers which do have various speeds and storage, but for my own of view, the Arduino has a much better open-source community which is really perfect.

in addition to the online community, Arduino is better because of its easy Arduino IDE compiler, which is considered much faster to program with comparison to the MPLAB for microchip