Playwithmyled.com

Too much on a hurry when I choose my Raspberry Pi password, and I wrongly noted it. There is a way to reset the pi user password.

1. Insert the card in your Mac SD card reader (must work on Window too);
2. Edit the file “cmdline.txt” and append “init=/bin/sh” (thanks Joe Schmoe). The Rpi will boot in single user mode;
3. Insert the card in the RPi again and boot up;
4. When prompt available, enter “su” to log as root (with no password);
5. Type “passwd pi” and enter a new password;
6. Remember the new password;
7. Remove the appended string in the “cmdfile.txt” file. Voila!

If you need a password for the root and you don’t have it either, edit the “/etc/shadow” file and replace the root password with a asterisk. Then it will be no password for the root user. (not tested yet).

I finally manage to find a way to make actuators that are enough powerful, small and the most important, noiseless. Since this robot will move all day long, it is essential not to hear it. I tried three types of motors: servos, DCs and steppers. It is not a secret for everyone, theses servos are terribly noisy. The gearbox of miniature DC motor I tried next is too noisy too. At last, I ordered a small stepper with a gearbox and it will be the one selected for the task. So I will replace the three servo motors with these steppers connected to a threaded rod that will move the swash plate.

I’ll have to 3D print some parts to fit all this together, but the essence is there. Now I have to learn to CAD.

There are the two motors, the stepper and the small geared DC one

Testing the small step motor