I was going to post a video, but I can't even get to "First Flight", or get Putty connection. So it is a connectivity issue at the moment.
I started from the beginning, and re-installed the img file and then get-apt install apm-copter-pxfmini.
(NOTE: I did not "decompress" the downloaded img file as stated in the instructions. It didn't make sense, and when I tried this it showed an error for the internal img file.)
I did this with a eth connection, and Erle was listed on my router.
I then rebooted with wifi and I thought I detected a successful wifi connection with iwconfig.
But then later it didn't seem to show, and didn't see it on my router.
IEEE 802.11bgn ESSID:off/any
Mode: Managed Access Point: Not Associated Tx-Power=20dBm
Retry short limt: 7 RTS thr:off Fragment thr:off
no wireless extensions
I tried Putty with 10.0.0.1 / 22 but it timed out.
I tried Putty with eth connected but no luck.
My router shows some assigned ip's for Erle also.
I saw a LAN ip in ifconfig, provided by the router, so I used it. It worked with Putty.
Despite Putty connection, Mavlink never connected to Erle.