Is it still true that you CANNOT connect a USB keyboard or keypad to any Particle computer's USB port?


#1

I see postings from 5+ years ago indicating that you CANNOT connect a USB keyboard to any Particle computer because it doesn’t support “Host Mode”. Is this still true?

Is there a well accepted work around, such as adding some piece of hardware that would allow a keyboard to be connected (and I am not preferring to connecting a PC;)

It seems reasonable to want to connect a keyboard, and a lot of people se4em to be asking for this. I was hoping there was some good solution now.

I want to use Particle but need a good way for people to key in words via keyboard.


#2

It is not possible to connect a USB keyboard to a Particle device. There are two problems:

One is electrical. Host mode requires powering the USB bus to power the keyboard. Particle devices are intended to receive power from the USB bus, not supply it.

The other is a software issue that there is no software support for host mode. Even if host mode was supported, it would require device drivers for specific devices classes like keyboard HID.

It’s unlikely that this will ever be supported.


#3

You can connect a serial (i.e. PS/2) keyboard to a Particle - there is a library. I know that PS/2 serial keyboard isn’t that common but they are still available - they will use 2 GPIO pins and have 5V logic so will need a level shifter for Gen3. Actually, having a buffer is a good idea because initially I blew the pins on a coupel of Photons due to EMC pulse in the keyboard signal lines.


#4

maybe with something like this? -> https://www.adafruit.com/product/1136