Pi-Over - Rover with a Raspberry Pi by truehybridx

Last crawled date: 3 years ago

Pi-Over v0.1:
***This project isn’t expected to be improved any except for the controlling software. I made this solely to get my mind into robotics and any advancements will go toward my next rover project.
This is a mildly simple 3 wheeled rover controlled by a Raspberry Pi. The particular model is a Model A with a cheapo Wifi USB Dongle that connects to my home network using a static IP for my client app on Mac to connect from.
Hardware:
The rover body is 1/8inch MDF measuring 200mm by 175mm with an extension added on to move the caster further out and increase stability. The Platform.skp should probably be modified to be longer in the back if one doesn’t wish to add this separate piece (assuming they use a CNC Mill like I did.) The Platform already has mounting holes for the wheel brackets which were printed in PLA using 0.1 infill. The drive wheels were clobbered together from settings I made from thing:21486, I suggest redoing that part completely as I made the hub too long and needed to chop some off to even get the set screw to make contact with the motor shaft. The motors are two Minebea geared stepper motors that I had on hand to be used in some of the Micro Extruders found on Thingiverse. Finally the rear caster was a modified version of thing:158553 where I added a slot for 608 bearings to pivot on a 8mm threaded rod.
Electronics:
The rover is controlled by a Raspberry Pi Model A running Raspbian and a little server program (the code in current state will be provided.) The motor drivers are StepStick’s plugged into a custom made interface board that hooks into power and the Raspberry Pi’s GPIO connector. The interface board also has a 7805 voltage regulator to drop the battery power down to the 5 volts for the logic and Raspberry Pi. The battery is a 11.1v 2250mAH Li-Poly battery stolen from a Parrot AR-Drone (I now have 3 so I can afford to miss the one that doesn’t fit well.)
Software:
The server program running on the Raspberry Pi uses a simple socket setup that talks on port 5270 that a client application connects to and controls the rover from. To compile the Pi needs to have the wiringPi library installed so you can compile using -lwiringPiDev. The client is currently just a native Mac Application which uses a wrapper of C style sockets, it should be straight forward to adapt this to whatever platform is desired, just pay attention to the actual command codes being sent.
Conclusion:
There are currently no plans to update this particular model as far as the hardware goes, I have something to play with now and advance software with for future projects, With that in mind, I do plan on adding to the software to make the controls a bit more fluid but I am unsure if I will keep this archive up to date with that.
Sources:
Wheels - http://www.thingiverse.com/thing:21486
Caster - http://www.thingiverse.com/thing:158553
Pi Bracket - http://www.thingiverse.com/thing:43587