So I have an unusual application for a Raspberry Pi. Basically, what I need is for it to connect to a device via serial port, then send that data over a network, then have a Windows computer be able to receive that data, but as a serial port. In other words, if I'm in a program that requires serial data, I want to be able to select that COM port just as if it were attached to the local computer. I've done some Googling and it looks like Ser2Net has some promise, but it's largely undocumented, and I'm lost on what to look for on the Windows side of things. Does anyone understand what I'm getting at?
Thanks!
1. The Raspi has no standard serial port (only LVTTL UART), get an FT232 dongle. Not any cheap USB-to-serial converter, but an FT232 (FTDI) one. These are more expensive, but you will thank me later. Plug that into Raspi's USB port.
1A. Actually, since Raspi is known to have an underpowered +5V rail and the smallest voltage drop will reboot the CPU, get a powered USB hub and plug all your peripherials (including the dongle) into that, not into Raspi directly. You will thank me later for that also.
2. After plugging the dongle in run
dmesg
In the last line of the output you should see a report that an FTDI device is plugged in. Then run
ls /dev/ttyUSB*
this should show what device name the FTDI device uses (/dev/ttyUSB0, /dev/ttyUSB1 and so on).
3. You need a serial-to-tcp bridge on raspi. The manual for ser2net is here:
http://linux.die.net/man/8/ser2net
and this is a good tutorial:
https://mellowd.co.uk/ccie/?tag=ser2net
(I'd disable the banner though, see the manual how to do that)
4. Verify that you can connect to ser2net from Windows machine via putty. (The tutorial uses telnet, but you're better off if you use putty with connection type Raw. You will thank me later). This is a critical step. Verify that you can talk to the serial device from windows.
5. You need a serial port redirector for Windows. This one:
http://www.hw-group.com/products/hw_vsp/index_en.html
worked fine for me and it's free if you need only one port. This creates a new COM port in windows which sends data over the TCP socket to raspi.
6. Launch putty and connect to the newly created COM port. Verify that you can talk to the device.
7. Profit!
Alternatively, if you want something which is more bulletproof (*) than raspi and you have money get one of these:
http://www.moxa.com/product/Serial_Device_Servers.htm
you can configure them simply via a web browser and there is a windows software included (though HW VSP will work also).
(*) Literally:
https://www.youtube.com/watch?v=o9daC24kUHY
https://www.youtube.com/watch?v=pCf6yZPcEGs
