LPC Microcontrollers中的主题 Re: USB-Serial bridging with LPC5x / any generic projects avail?

USB-Serial bridging with LPC5x / any generic projects avail?

dav1 — Tue, 29 Dec 2020 22:25:59 GMT

I've been looking for a generic implementation that implements a run-time (by the host) configurable serial bridge that is completely driverless.

The closest thing would be this part: CY7C65215 (https://www.cypress.com/file/129956/download)
it has 2x CDC UART's (compliant so driverless on mac, linux as opposed to FTDI), 2x SPI and 2x I2C.

Performance should not be worse than the peripheral on the MCU it runs on. I believe python with asyncio + libusb would do well on the host-side to keep it generic.

Anyone seen something like this or do NXP happen to have some CDC bridging examples for LPC or i.MXRT series that comes with a side-channel (or additional cdc endpoint) to configure baud-rate, flow-control, etc.!?

Re: USB-Serial bridging with LPC5x / any generic projects avail?

xiangjun_rong — Wed, 30 Dec 2020 03:04:58 GMT

Hi, David,

The LPC55xx supports CDC class as device as you expected, in CDC class, it has two channel based on CDC class protocol, one channel is controlling channel, with which the host side can set up baud rate, data format, data width..., another channel is data channel, with which data can be transferred.

In SDK package, we have implemented the usb stack including CDC, and we have developed a lot of examples.

https://mcuxpresso.nxp.com/en/welcome

With the CDC class, you can transmit and receive data via USB, with the data, you can transfer them via SPI, uart, I2C, I think it is so-called bridge.

Hope it can help you

XiangJun Rong

Re: USB-Serial bridging with LPC5x / any generic projects avail?

dav1 — Wed, 30 Dec 2020 21:18:59 GMT

Hi XiangJun and thanks for replying

- Does NXP provide any host code to interact with the custom "configuration CDC channel"?

- For I2C, SPI etc, we can of course add this ourselves, was just curious if there are some nxp-provided libraries similar to what Cypress has for their KitProg3's, and Serial Bridge IC's that cover all scenarios incl. the Host side.

- Is there a way to access this code without installing the full tool-chain? i.e. is the CDC driver and example code available in a git repository somewhere?

Re: USB-Serial bridging with LPC5x / any generic projects avail?

xiangjun_rong — Thu, 31 Dec 2020 05:45:01 GMT

Hi, David,

Unfortunately, I have not idea how to develop the USB project on PC side based on Windows.

XiangJun Rong

Re: USB-Serial bridging with LPC5x / any generic projects avail?

belmontbob59 — Tue, 05 Jan 2021 18:34:27 GMT

For Windows 10 you no longer need to worry about providing kernel driver support for CDC; It is already included in the OS as a class driver. i.e. plug and play.

https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/supported-usb-classes.