Lessons Learned: October, 2017

Lessons Learned is a collection of issues and failures that I encounter each month. Each entry explains the problem that I encountered, the solution I reached, and what I learned from it.

This list will be updated periodically.
Last Updated: 2017-10-03


'Error: Invalid Serial Connection', 2017-10-01

Problem: While working with the Proxmark3 Easy, I followed a guide for set-up. After successfully building the software I encountered the error "Error: Invalid Serial Connection" when attempting to communicate with the Proxmark 3 Easy.
Solution: sudo adduser $USER serial followed by logging out and back in.
Learned: When working from a chroot on ChromeOS: explicitly add chroot users to necessary groups to access devices directly. While Crouton maps groups such as HWaudio, USB, and serial through to the chroot, it does not automatically assign users to these groups.

WiFi Spectrum Analysis Issue, 2017-10-03

Problem: Three separate WiFi spectrum analyzers failed to load or detect any networks, despite the host computer having no difficulties finding and connecting to access points.
Solution: Delete a Hyper-V virtual switch that is sharing the outbound network connection with the host OS.
Learned: The software needs to be able to directly communicate with the network adapter. When a virtual switch is configured to share the network connection, Hyper-V will insert itself between the host OS and the hardware transparently. This does not generate errors but does not return information such as the wireless channel, RSSI, or available networks.


Proxmark3 Easy; Firmware Flash, 2017-10-01

Problem: Following a guide I attempted to flash the BOOTROM. Bricked the device.
Solution: Buy a new Proxmark3 someday.
Learned: Do not attempt to update the firmware of a Proxmark3 Easy. It is fine as is.

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