BE CAREFULL because I will not answer in some cases:
1- If the answer is already written in the site and it was enough to read.
2- If you ask me things to sell.
3- If you ask me to do your student project (yes, there have been).
4- If it is to build a real trawler (here too it is lived).
For all other things, it will be a pleasure to exchange some emails with you.