Review on 🔌 JBtek USB to RS485 Converter Adapter: High-Quality ch340T Chip, 64-bit Windows 7 Compatibility by Shane Jess

Some of these worked between a Win7 laptop and a Raspberry Pi 2 USB port with a 4ft cable at speeds of 230400, 460800 and 500000 bps. It doesn't work at 576000 bps or higher on the R-Pi. Between the two Win7 ports it ran at 921600. I didn't need to install any drivers on either computer. The RPi command lsusb says "1a86:7523 QinHeng Electronics HL-340 USB-Serial Adapter" and dmesg says USB2.0-Serial, USB Serial Support is registered for ch341-uart which is now connected to ttyUSB0. The waveform on the scope above 230400 looks bad. So if you need high speed, I suggest something else. EDIT: Oddly another Win7 PC couldn't load the driver automatically, but I got them from www.cesareriva.com/usb-to-serial-converter-hl-340-drivers/