On Yosemite, I used the kernel dev hack mentioned in the post I linked to. This will not work for El Capitan and you will have to download and the El Capitan driver in that same post. I do not know whether or not that driver works with Yosemite, but it is a signed driver that is more current than the one on the Makeblock repo on Github.
My reset sequence is:
- Connect via the USB cable to the correct serial port.
- Upgrade the firmware.
- Reset Default Program
This process has always worked for resetting the mBot for me. You should hear the three tone startup sequence after the default program has been reset.
If you are getting prompted to connect the serial port, you need to connect the USB cable and select the correct serial port. If you are using WiFi or Bluetooth, you will need to disconnect from them first.
If the upgrade or program reset is not completing the upload, you may need to contact support@makeblock.cc with the issue.
If an error occurs during compilation during either the Upgrade Firmware or Reset Default Program operation, you need to contact support@makeblock.cc to get the issue resolved.
I’m not sure what else might be the issue.