Any USB to Serial converters that don't need driver installation?

[Ben321]

I know with webcams, as long as it follows the UVC (usb video class) standard, it will run out of the box, without installing a driver provided specifically for the camera. Same thing with USB mice and keyboards. They use a standard that lets them run without you needing to install drivers from a CD (or company website download).

Is there a similar standard for USB to serial converters, that allows them to work out of the box, without installing a driver (just using the default driver that comes with Windows)? If so, can you list some decent USB to serial converters that follow this standard? Like what companies are known to make such "driverless" USB to serial converters? I'd like to know, so I can look them up by name on Amazon.

[ataradov]

Windows will need an INF file at the very least.

Otherwise any device implementing CDC ACM protocol will work with a standard usbser driver, but it will have to be referenced from an INF file.

If I'm not mistaken, CH340 is one of such devices.

[nctnico]

Windows will need an INF file at the very least.

Otherwise any device implementing CDC ACM protocol will work with a standard usbser driver, but it will have to be referenced from an INF file.

WIndows10 won't need an .inf file for a USB CDC device. The previous WIndows versions (unfortunately) do (AFAIK) but even then a USB CDC modem is your best bet because the .inf file is easy to create (it is plain text so notepad will do).

[Ben321]

Yes. USB CDC ACM.

Not all USB UART bridges support it. Cypress' PSoC USBFS module uses this protocol and it driver-free.

Beware that many "new era" USB class drivers are only introduced in Windows 10 (i.e., USB CDC introduced since 8.1, USB audio 2.0 introduced since Win10 1703).

AFAIK there're no Win7 driver-free USB serial ports, but Windows Update should be able to fetch common ones like FTDI and Silabs.

Linux has virtually all common USB-UART drivers built-in, so there's no worries.

Macos does NOT have Silabs driver built-in. I don't use FTDI, so I can't tell. Cypress USB CDC works fine driverless.

I had been reading about FTDI. I thought that was the name of the official driverless USB-to-serial standard. I assumed all versions of Windows from XP and newer had default FTDI drivers installed.

Also, I notice that Zadig (the software that lets you install generic USB drivers like WinUSB for any USB device you have connected to your computer), has an option to install "USB Serial (CDC)" as the driver for a device. The other options are WinUSB, libusb-win32, and libusbK. So by using Zadig (no need to run windows update, or install from a CD), it might be possible to use USB-to-serial converters that support the generic CDC driver (and possibly other types of usb-to-serial converters too, by installing this generic driver).

[ataradov]

No, FTDI is a name of a shitty company that bricks their own devices. Their protocols are very similar to standard CDC ACM, but slightly different.

[nctnico]

I agree. Stay clear from FTDI!

[Ben321]

No, FTDI is a name of a shitty company that bricks their own devices. Their protocols are very similar to standard CDC ACM, but slightly different.

What happens if I use Zadig to install the CDC driver for a USB-to-serial converter that isn't a generic device? Will it somehow know how to work with it? Or does Zadig installation of the CDC driver only work if the device itself is generic?
Do you know of any usb2serial converters that actually are generic, and work with CDC drivers?

[ataradov]

Zadig won't help you here at all. If you want to work with the device as with an actual COM port, then you need to install correct drivers.

CH340 is a CDC ACM device as dar ad I can tell, but I don't have any real hardware to try.

[Ben321]

Zadig won't help you here at all. If you want to work with the device as with an actual COM port, then you need to install correct drivers.

CH340 is a CDC ACM device as dar ad I can tell, but I don't have any real hardware to try.

Then why does Zadig have an option to install a CDC driver?

[Psi]

I'm pretty sure that CP2102 works in win10 without the user having to install a driver.
But it's not something i've tested to confirm.

Keep in mind if you want to distribute some software to support your hardware the OS they are running could be anything.
WinXP, 7, 8, or 10.   etc.

I doubt CP2102 will work in winXP without a driver install

[ataradov]

Then why does Zadig have an option to install a CDC driver?

This must be something new. I have not seen this.

But in any case, at most it will generate the same INF file, which will reference usbser.sys driver. It should work with any CDC ACM device, but not FTDI, for sure.

[Ben321]

CP2102? CH340? These are chips. I'm not looking for bare chips. I'm looking for a CDC compatible product that a company is manufacturing, that can just be plugged into your USB port and it's good to go. If those chips are CDC compatible, then can you name some products that use those chips? Like what well known companies are actually making generic USB2serial converters? Or do I need to look at cheap China stuff on eBay to find one?

[ataradov]

I'm not aware of any finished devices like that. Most of the stuff available from China uses fake versions of legitimate chips, and not always works correctly.

The only way to find out is to buy a few of not the cheapest cables and check them out.

[ataradov]

Why don't buy PSoC gum stick kit and configure it as USB UART? Guaranteed genuine, plus you get some processing if you wish so.

I don't mind. I have plenty of SAM D11-based adapters. OP wants a readily available finished device.

[NorthGuy]

If you just want USB communications, not necessarily a COM port, you can use a HID USB instead of CDC. It has built-in drivers in all OSes going back many years.

[Ben321]

If you just want USB communications, not necessarily a COM port, you can use a HID USB instead of CDC. It has built-in drivers in all OSes going back many years.

HID must configure itself as a keyboard or mouse. Keyboard and mouse will conflict with existing keyboard and mouse. If my peripheral sends a "move right" command my mouse cursor will move right on the screen. Not exactly what I want. Also HID is intended as input INTO a computer, and can't take commands going from the computer to the peripheral. What I have 10 LEDs I want to independantly control? What if I want to send a string of 8bit ascii text to an external LCD display? All of these are best done with a serial port.

[ataradov]

No, HID is a generic transfer protocol, it does not have to be a keyboard or a mouse.

ARM CMSIS-DAP uses HID for all programmers/debuggers, which lets them work on all OSes without a driver.

Here is example of a project that uses HID to transfer data that has nothing to do with input devices https://github.com/ataradov/dgw

[Ben321]

No, HID is a generic transfer protocol, it does not have to be a keyboard or a mouse.

ARM CMSIS-DAP uses HID for all programmers/debuggers, which lets them work on all OSes without a driver.

Even so, serial ports are great (better than USB), because they have several independant lines, including 4 status (CD, RI, DSR, CTS) lines that can act like a 4-bit parallel port, or like 4 GPIO-input pins. This is great for reading up to 4 external digital signals. HID doesn't do this. It is a USB protocol, and USB only has voltage+, voltage-, data+, data- pins. So that means it's like a parallel port without the other status pins. So you can't do all the other cool stuff you can with a serial port. Instead, you would need some kind of external chip to interpret the USB commands, and export the bits to separate pins. USB by itself, is just a high speed serial port with ONLY serial data (unlike a COM port which has small amount of parallel capability). And you need a UART to convert serial to parallel.

[ataradov]

If you implement HID, you would have to use an MCU and implement whatever application-specific behavior you need. That project above has not just 4 pins, but I2C, SPI, GPIO, ADC, DAC and PWM at the same time.

This is only an option if are talking about doing custom hardware. There is no standard chips (that are not generic MCUs) that would do that.

[Ben321]

If you implement HID, you would have to use an MCU and implement whatever application-specific behavior you need. That project above has not just 4 pins, but I2C, SPI, GPIO, ADC, DAC and PWM at the same time.

This is only an option if are talking about doing custom hardware. There is no standard chips (that are not generic MCUs) that would do that.

What's MCU?

Are there any existing pre-soldered devices (not kits) that have a way of outputting 8 parallel bits (not serial, and no specific standard like I2C) from input data coming into it as an HID device on  a USB port? Or alternatively, can they take 8 parallel bits of input and then serialize it to transmit it via HID USB back to the host computer?

[ataradov]

Are there any existing pre-soldered devices (not kits) that have a way of outputting 8 parallel bits (not serial, and no specific standard like I2C) from input data coming into it as an HID device on  a USB port?

Not that I'm aware of.

There are USB-to-FIFO chips (for example FTDI FT245) that will translate your virtual COM-port into 8 parallel I/O lines. But again, this is a bare chip, I'm not aware of any commercial devices that would do this.

You want very strange things, this is what MCUs are for.

[Ben321]

Are there any existing pre-soldered devices (not kits) that have a way of outputting 8 parallel bits (not serial, and no specific standard like I2C) from input data coming into it as an HID device on  a USB port?

Not that I'm aware of.

There are USB-to-FIFO chips (for example FTDI FT245) that will translate your virtual COM-port into 8 parallel I/O lines. But again, this is a bare chip, I'm not aware of any commercial devices that would do this.

You want very strange things, this is what MCUs are for.

What's an MCU?

[ataradov]

Microcontroller.

[Ian.M]

Its not *impossible* to find HID parallel I/O boards.
Here's a pre-built board (using a pre-programmed PIC MCU) with eight output lines: https://www.velleman.eu/products/view/?id=404998
If you go to the kit version, it tells you its a HID device.  However I wouldn't recommend it as Velleman don't provide documentation on how to access it as a raw HID protocol device.