Hello,

Could you send us a copy of the descriptor which the PC receives and also details on which keyboard chipset you use.

You can reply here or send to our support address support1@ftdichip.com if you prefer.

Thanks,
FTDI Community

Hello,

We are dealing with your request via email. Please feel free to add any resolution here when complete to help other community users.

Best Regards,
FTDI Community

Hello,

One thing you could do is to check with USBview as shown below. This allows you to see if a device returns descriptors correctly. If the details such as idVendor and idProduct (VID and PID) are zeros then the device has not been able to communicate properly with the PC.

https://www.ftdichip.com/Support/Utilities.htm#MicrosoftUSBView

Best Regards,
FTDI Community

Hello,

The schematic generally looks ok.

Is the behaviour the same on a Windows PC?

Please test in a loopback fashion to rule out any issue with the communication to the MCU.

Simply connect TXD to RXD and use a terminal program like PuTTY to send/receive characters.
Note that PuTTY will only show received characters unless your force ON the sent characters.

Please also test with our known good hardware which you can also use for reference:

https://www.ftdichip.com/Products/Modules/DevelopmentModules.htm

Best Regards,
FTDI Community

Hello,

You have sent us an email on this matter. Feel free to post any resolution here to help other forum users.

Best Regards,
FTDI Community

Hello,

The FT260 would appear as a HID class device but not exactly like a keyboard.
It doesn’t use FTDI drivers but uses standard HID class drivers.
Feel free to evaluate using the UMFT260EV1A.

The other real keyboard solution we have is FT90x / FT93x. This has a programmable USB device controller. We have already produced a keyboard example in AN_360 FT9xx Example Applications. See USBD Example HID . This is a bigger MCU though.

Best Regards,
FTDI Community

Hi,

Glad it helped and thanks for letting us know,

Just to add, if you were originally trying to update variables on the screen without re-sending the command list, it is generally necessary to re-send the commands to create each screen update rather than have a change reflected on the screen in real time.

There are a couple of techniques that can help minimise the amount of the display which you re-send in AN_340 below and we also use the technique in several other examples such as section 9 of BRT_AN_014 and our sample apps too.

https://brtchip.com/wp-content/uploads/Support/Documentation/Application_Notes/ICs/EVE/AN_340_FT800_Optimising-screen-updates-with-Macro-and-Append.pdf

https://brtchip.com/wp-content/uploads/Support/Documentation/Application_Notes/ICs/EVE/BRT_AN_014_FT81X_Simple_PIC_Library_Examples.pdf

Best Regards, FTDI Community

Hi,

You can use string commands (such as sprintf) to write a string into the string variable x. This will allow you to create the string and then display it rather than have the hard-coded text string.

Best Regards,
FTDI Community