Does anybody know if there is a commercially available adapter that lets me talk to a USB device through a serial port? I work at a National Laboratory, and you would think we are on the cutting edge, but we are not. We have huge data acquisition systems that work on a flavor of UNIX and it does not support USB. It does handle serial though. I would like to purchase an instrument from Thorlabs that only works over USB, and then use a serial to USB adapter to talk to it. One would think that this is just some sort of baud rate converter since USB is still a serial protocol. If you want to know the device I want to talk to, it is on the Thorlabs website with part number PRM1Z8E.
I have used Pic microcontrollers to build my own baud rate converters before, but I have no time for this project. I’m looking to purchase off the shelf.
Consider using a small Linux SBC such as a raspberry pi. Plug in the USB device into a Linux USB host port. Hopefully, Linux has a driver for the device. Next write a program (perl, python, etc.) to open the USB device, open a UART port (raspberry pi has one), and pass data between the USB device and UART.
I think you could do the same thing using an Arduino + USB host shield but I have never tried this. In either case, some coding is required.
If you want an IC instead of going the SBC/PI route, then look at FTDI’s VNC2 chip. It can talk to many different kinds of USB devices using a serial protocol.
Ditto on the Raspberry Pi. There’s a utility called socat that allows you to link two serial ports. You’ll need a USB/RS232 adapter as well. Save yourself some grief and get a genuine FTDI adapter from Mouser or Digikey for $15. About 10 minutes worth of work
