One-Wire behind UART XR21B1411


I have a one-wire device behind a Exar XR21B1411 USB UART that I need to access with an Arduino. I have the Arduino USB host shield and tried to use the cdc_XR21B1411 example from the Host Shield library 2.0 but had no success. It seems to me that I have to use the One-Wire protocoll over usb. Any hints or ideas on how to use this? Is there a library available that can send low-level one-wire commands over the USB host shield? It is not possible to detach the One-Wire sensor form the UART, unfortunately.

Any idea is appreciated, I have to get this working, but since few days no success.

Regards, durpex

I have a one-wire device behind a Exar XR21B1411 USB UART

Why do you think a UART can talk to a 1-wire device? A UART is a full-duplex device:

  • two wires, each one dedicated to a certain communication "direction" (send or receive)
  • usually used for point-to-point communication (2 nodes)
  • neither node is a master
  • both wires can be used at the same (both nodes can simultaneously send and receive)

The 1-wire interface is half-duplex:

  • one wire is shared for both directions
  • used for network communications (n nodes)
  • one device transmits and n-1 devices receive (only one transmitter at a time)
  • one device is designated the "master"

Or are you trying to use the GPIO pins to implement the 1-wire interface? The RX/TX pins cannot be used for 1-wire.

We need to see a schematic and system diagram of what you are trying to do.

Cheers, /dev

What 1 wire device are you talking about? Maybe you can just get a version that is not connected to the XR21B1411. I assume the device is normally controlled/read from a PC and if it is then did you need to install special drivers/software to use it. The XR21B1411 has a few GPIO pins that maybe could be controlled by a custom USB driver and this is possibly how 1 wire is read/written.