Special question on creating an Altcoin

[atmega]

First off, hello to all!
Recently I had an idea for a new Altcoin. I know that there is no need for a thousand Bitcoin clones, but my idea is - well different. I have the following problems:
1. I need to have an integrated miner. This is why I chose Litecoin as a basis. But as I saw there is no more miner in the current source. Can I just use an old one maybe?
2. I need to change the hashing algorithm. To be precise hashing will be done externally. I thought of this the following way:
Litecoin: last_block_data + random_number ---> script algorithm ---> output
My Coin: last_block_data + random_number ---> usb to rs232 converter ---> my_device ---> back to pc via rs232 to usb converter ---> output

How difficult is that to accomplish? I have no experience in C++, because normally I program in C for microcontrollers.
Thank you all so much for your help 

[raspcoin]

Unfortunately, I do not understand what you are trying to achieve. However, in any case, I would recommend to use Primecoin as a basis rather than Litecoin. That way your coin will do some good work, while the other differences are minor.

[atmega]

Hello
Well, what I`m trying to archive, is to not hash on the CPU or GPU, but on an external chip. The way I thought about this is that normally the number gets pushed through an algorithm like SHA-256 or Scrypt to produce a hash, but I want to send the number via RS232 to an external chip, which will then use a different algorithm for hashing...
Thank you very much for your reply