TeraTerm shows garbage if SD inserted


TeraTerm shows garbage if I connect the pixhawk to it with an inserted SD.
As soon as I have no SD inserted, TeraTerm works.

But this is a problem because I want to do this tutorial:

And in this tutorial it shows you how to access the SD card via TeraTerm.

So what is the solution to this problem?

The garbage you’re seeing are mavlink messages intended for QGC.

What version of PX4 are you using?

It used to be that PX4 decides whether to start mavlink over USB (needed to connect to QGC) or a nuttshell (needed to connect to the device via a shell) based on whether the SD card is inserted.
This was done in this file https://github.com/PX4/Firmware/blob/master/ROMFS/px4fmu_common/init.d/rcS

The switch appears to have been removed recently though, so I don’t know how you would access the shell on current master.

You might have luck by replacing this line with
nshterm /dev/ttyACM0 &

Please use the system console instructions: http://dev.px4.io/advanced-system-console.html