IMX6Quad usbserial driver

[joe_stewart]

I have a i.MX 6Quad Sabre-SD. I am trying to connect to another micro controller via the usbserial driver. I ran the following:
1. modprobe usbserial vendor=0x067b product=0x2303 - got message saying that the generic converter is attached to ttyUSB0
2. Created python script
         import serial
         import serial
         ser = serial.Serial('/dev/ttyUSB0', 115200, timeout=0)
         ser.open()
         while True:
            ser.write('f0'.encode() - returns 2
            time.sleep(1)
I have a mircousb to usb connected on one side to the usb otg on the board. The other side is connected to a Trendnet TU-S9 usb to serial converter. I have a scope hooked to pin 3 (transmit) and pin 5 (ground) of the TU-S9. When I run the above script, I see a constant -6 volts on pin 3.
I am confused as to why the driver does not appear to be working. Any help on this would be greatly appreciated.

[igorpadykov]

Hi Joe

one can try with usb unit test, usb driver is described in sect.4.10 USB

attached Linux Manual

mxc_usb_test\test - imx-test - i.MX Driver Test Application Software 

Linux Binary Demo Files - i.MX 6QuadPlus, i.MX 6Quad, i.MX 6DualPlus,
i.MX 6Dual, i.MX 6DualLite, i.MX 6Solo, i.MX 6SoloX

https://www.nxp.com/webapp/Download?colCode=L4.9.88_2.0.0_MX6QDLSOLOX&appType=license&location=null&... 

Best regards
igor
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