Take command of your BASH prompt

color_bash_prompt

[Joshua] has put together a list of BASH prompt customizations. The command prompt is used in a command-line interface to show that the system is ready for the next command. Often times this is nothing more than a user name, host name, and working directory:

mike@krusty:~$

[Joshua’s] customization examples can be used to color code the information in your prompt, change what information is displayed, and make the prompt respond differently when an invalid command is typed. A BASH prompt reference is helpful in deciphering what each of these commands do. The easiest simplification is to understand that non-printing characters (such as color codes) are surrounded in escaped square brackets. For example, line 1 is the sequence for Red, line 2 is the sequence for Dark Grey, and line 3 sets a simple prompt to display in Red and all text after that to be in Dark Grey:

\[\e[0;31m\]
\[\e[1;33m\]
PS1="\[\e[0;31m\]\u@\h:\w\$ \[\e[1;30m\]"

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Harry Potter Marauders map realized

21nokia-booklet-3g-group

After reading about cheap wireless for microcontrollers, [Leigh] left a comment about his Marauders map. Much like the Harry Potter version, whoever holds the ‘map’ is able to see the location of the ‘marauders’ within certain bounds. Unlike the magical version however, each person being tracked needs to hold a PICAXE 08M, GPS, and 433.92MHz transmitter: while the map needs a computer running his Python script and a receiver of the same frequency. It has the potential for locating people, but we feel it might be better off in a swarm robotics setup.

Programmable spring actuator legs

This proof of concept shows an interesting way of making robotic legs. They are using programmable spring actuators to make these legs function as though they had a “reflex”.  The builder pulls the robot along on a leash. As the leg reaches its limit of backward motion, a signal is sent from the shoulder down to the knee that lifts it, causing it to return to the forward position. A signal is also sent to the opposing shoulder to suppress the lift reflex, keeping them from both stepping at the same time. The resulting motion is very organic feeling. We’re curious how this could be implemented in a robot which moves under its own power.

[via makezine]

Arduino email alert

email

The Arduino makes a great platform for alert systems because it doesn’t need additional parts, other than an LED or motor. [Torchris] made email notifier, and used an Ethernet shield to make it standalone. The Arduino polls your POP server seeing if there are unread emails. POP is an incredibly simple protocol, even simpler than HTTP; this made it easy to communicate with, even with little processing power. He hopes to add a servo or serial display to present the data better, but his current system seems to work well. Video of it in action after the break.

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