Upload fails on certain USB-TTL adapters

[brahmafear]

Plugin works for me when using certain USB-TTL adapters but fails (freezes progress) on certain models. Posting here in case anyone has seen same issue. Tested with two models of problem

adapter listed below - both show same issue. (Both work perfectly when uploading sketch from IDE.)

Mac OS X 10.11.6
Arduino IDE 1.6.12
USB-TTL prodID 6001, vendID 0403

Note: this USB-TTL adapter is supposedly an FTDI chip, but since I got them for cheap online, I'm open to the possibility that they are clones. However, posting issue in case this is indicative of a problem in the plugin code.

Attached file shows where progress in IDE upload freezes. This is running the upload plugin on the FSBrowser example sketch in ESPWebServer package.

[brahmafear]

More info: only way to "unfreeze" the IDE is to disconnect the USB connection to the USB-TTL adapter. Upon doing so, the following is shown in the IDE:

Uploading 131072 bytes from /var/folders/nb/dtcb7q0555nbdbjgslnf64fr0000gp/T/arduino_build_935934/FSBrowser.spiffs.bin to flash at 0x0005B000
...................................Error while setting serial port parameters: 115,200 N 8 1
warning: espcomm_send_command: didn't receive command response
warning: espcomm_send_command(FLASH_DOWNLOAD_DATA) failed
error: failed sending 0xC0
error: failed sending 8 bytes
error: failed sending 4 bytes
error: failed sending 0xC0
warning: espcomm_send_command: didn't receive command response
error: espcomm_upload_mem failed
SPIFFS Upload failed!

[me-no-dev]

this looks like FTDI adapter. See to update the driver and preferably have it connected through USB hub. It's something to do with USB on Mac

[brahmafear]

Very possible. In either case, I can work around by using a different adapter. Will mark issue as closed. The thread will remain searchable in case it happens to anyone else in future. Thanks.

[brahmafear]

More info for future:
Installed official FTDI v2.3 driver for OSX instead of using OSX built-in driver for FTDI: same issue, same behavior. Will test with USB hub when possible. Will blame issue on shady FTDI clone chip.