Which mini PC or MK to choose for receiving and storing data from RS-232 and transmitting them via TCP / IP?

Question

Do it yourself

Task:
1. send a request to the com port, get the data, add a timestamp and save it locally, the polling period is 10sec-1min.
2. Send the stored data via TCP/IP upon request, delete it locally upon confirmation of delivery, the polling period is 1-10 days.
3. Track the empty space on the local storage, in case of overflow, overwrite the old data.
I see the implementation logic something like this: implement a com port poll via UART-> COM or USB-> COM, take time from RTC, to store data either NAND, or SATA, or USB Flash, or SD cart (how long will a flash drive or SD card live ?), to transfer data to the SMB server.
Actually the question is: on which hardware is it better to implement based on the minimum price of iron and the reliability of operation in the long term?

Answer 1

You will hardly find a cheaper raspberry pi , COM can be connected directly to the pins or through any adapter.

Answer 2

Raspberry Pi or something like Asus Eee PC 701 - I'm just selling a couple.

Answer 3

There was also a com-port on the mk802, though the network was implemented via wifi there.