In the old Android release R10.3.x for i.MX5x, I had followed the user guide instructions to install the USB driver and am able to setup the ADB connection successfully. Unfortunately, for the same PC, the ADB fails to detect my i.MX6SL EVK which is using R13.5. Updating the Android SDK tools cannot help.
The reason is the new Android device is using a different USB VID from the old release. So, to solve this problem, we need to update the ADB configuration to scan for the new vendor ID. Below are the steps to update the ADB configuration for Windows PC. These steps (and the steps for Linux PC as well) can also be found in the R10,3.x user guide.
1. Run the SDK's tools to generate an ADB configure file:
# ANDROID 3RD PARTY USB VENDOR ID LIST -- DO NOT EDIT.
# USE 'android update adb' TO GENERATE.
# 1 USB VENDOR ID PER LINE.
3. Unpack the Freescale Android USB win driver "android_usb_fsl.zip" in your Android BSP release package. If you can't find this file in your current package, please get the R10.3.x release for i.MX5x and unpack it.
4. File "tetherxp.inf" in the unpacked "android_usb_fsl" may not be the updated one if the "android_usb_fsl.zip" is extracted from an old release. So, please overwrite the file "tetherxp.inf" in unpacked "android_usb_fsl.zip" by the new "tetherxp.inf" in your current Android BSP release.
5. Enable the "USB debugging" option on the i.MX6 device
System settings -> Developer options -> USB debugging
6. Connect the Android Device into PC, uninstall your old driver named "Android Phone" in the device manager, then re-install driver by scanning and locating .inf file under the directory you unpack the android_usb_fsl.zip manually.