Converting USB signal to UART - FTP232HPQ-TRAY (help needed) - Page 1
Forum section: electronics / projects

author: Dexter74
author_rank: Newbie
timestamp: May 31, 2022, 06:11:49 pm
content: Hi I've been working on a programming device that works like a middle man between computer and other PCBs with STM microchips. For specific reasons I need to branch out the USB signals, so I used a TUSB2036 USB HUB (it gets recognized by Windows so I suppose it works fine), making one upstream diff pair into two dowsntreams. From there the signal goes to FTP232HPQ that converts the USB signal into UART in order to communicate with STM Microchip. However the FTP232 microchip does not get detected properly (the datasheet says there are no drivers needed). I've tried a couple of fixes but it does not seem to help, so I am seeking an advice.The fixes I did so far were: on the TUSB2036 I switched pull up from DM to 3V3 to DP - that fixed the HUB, I also switched all the STF203-22 USB filters for 22Ohm resistors and I tried pulling up on the PD-CC pins of the FTP232 chip instead of pulling down.In the attachment should be the whole schematic of my device in pdf. Thanks for help <3

author: DavidAlfa
author_rank: Super Contributor
timestamp: May 31, 2022, 06:31:54 pm
content: So what's your question?

author: Dexter74
author_rank: Newbie
timestamp: May 31, 2022, 06:45:19 pm
content: I somehow posted just a partof the post, so I edited it

author: semir-t
author_rank: Regular Contributor
timestamp: May 31, 2022, 07:24:09 pm
content: On the linux system it is really easy to see if the USB devicea are being detected. For this purpose I use lsub or dmesg command through terminal.Maybe there is something similar for windows. Even though datasheet says that it doesn't need driver, if I waa using this device on windows I would check that out.

author: DavidAlfa
author_rank: Super Contributor
timestamp: June 01, 2022, 02:44:11 am
content: Windows: Just open the device manager.Doesn't any new COM port appear? Or unknown device?Check FTDI FT232HP dev board, has schematics:https://ftdichip.com/wp-content/uploads/2021/12/DS_FT232HP_SinkModule.pdf

author: Dexter74
author_rank: Newbie
timestamp: June 01, 2022, 02:08:56 pm
content: Thank you for the schematics, I will check that soon, Windows finds the device, but error occurs "device not migrated"

author: tooki
author_rank: Super Contributor
timestamp: June 01, 2022, 05:13:04 pm
content: Post the PCB layout. It's possible something there is wrong, causing signal integrity issues. I've seen this with other USB-UART bridges, too. Windows can then sorta see it, but not enough to properly enumerate and configure it.

author: SiliconWizard
author_rank: Super Contributor
timestamp: June 01, 2022, 05:17:44 pm
content: Quote from: Dexter74 on June 01, 2022, 02:08:56 pmI've never ever seen this Windows error and wondered what it could be. So I looked it up.Found this:https://answers.microsoft.com/en-us/windows/forum/all/device-not-migrated-error-in-windows-10/9e18a99a-0131-422e-8527-fa20b2793e9eThere's a chance your issue is not a hardware one, but a problem with device drivers. Are you on Windows 10? (I guess so as I've never seen this error on earlier versions of Windows?)

author: Dexter74
author_rank: Newbie
timestamp: June 02, 2022, 06:35:13 pm
content: Here is the PCB layout, highlighted traces are DP and DM

author: free_electron
author_rank: Super Contributor
timestamp: June 02, 2022, 06:58:46 pm
content: ditch that usb isolator and see if it enumerates properly without that thing in the loop. those isolators do weird things.... it is possible that your power sequencing is enough out of line that there is an "enumeration storm" occuring

author: Dexter74
author_rank: Newbie
timestamp: June 02, 2022, 07:18:08 pm
content: And here is the configuration of the Diff pair

author: Dexter74
author_rank: Newbie
timestamp: June 06, 2022, 09:32:58 pm
content: So after a few days of trying I still can not get the FTP (USB -> UART) chip to enumerate. I tried ditching the USB isolator and tried bridging it instead.I am thinking that the problem could lie in configuring the CC pins on both the FTP chip and the USB port. But I am a little bit confused about how to set them up. Could the problem be that the FTP chip thinks he is the host so it can not enumerate?