Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: wdomhart on July 14, 2009, 05:23:13 PM

Title: Spherical Robot Project MCU
Post by: wdomhart on July 14, 2009, 05:23:13 PM: Hi,

I'm over at Cal Poly SLO doing a project where I'm going to design a spherical robot. This is my first robot design, however I have worked with a Motorola MC6811 MCU a bit (yes, I know its old school), worked with steppers, and dc motors a little. I've decided that I'm not going to use the 6811 and the Mini Board 2.0 that it came with because I'm having finding a programming environment for windows and there's not much documentation or support for this chip/board combo. I'm thinking of going with an Atmel MCU, but would like a board combo.

Requirements:
Drive 2 hacked hobby servos, 1 DC motor, and 2 optical encoders.
Small in size, free software, USB support, and can interface with a radio controller.

Ideas. I have 4 weeks to get this thing going.

Thanks,

William
Title: Re: Spherical Robot Project MCU
Post by: kpmcgurk on July 14, 2009, 05:33:18 PM: Is it going to be autonomous or Remote controlled?
Title: Re: Spherical Robot Project MCU
Post by: wdomhart on July 14, 2009, 05:43:04 PM: Remote controlled. Not enough time. Have a lot of work and tests to do. I'm bouncing between two designs, but I need the MCU programmed enough so that I can conduct testing.
Title: Re: Spherical Robot Project MCU
Post by: Joker94 on July 20, 2009, 05:47:51 AM: can you give a better discription of the shape or a drawing, hand will do. I am haing trouble pictuing how the thing is going th work ???
Title: Re: Spherical Robot Project MCU
Post by: wdomhart on July 20, 2009, 08:58:03 AM: Got the board and I'm using an Atmega128 with a custom board from one of the professor's classes. The design isn't finalized, but the primary idea is to have the robot enclosed in a spherical hamster ball. The robot will be suspended in sphere with hangars connecting the the MCU/Battery/Motor platform with a rod centered on equator of the sphere. One motor will drive a wheel in contact with the inside of the sphere. Another motor will operate a flywheel of sorts that will run at a slow constant speed unless turning is required. When it recieves input to turn the motor will speed up or change direction depending on which way its turning. I need to test this idea out, but I'm thinking it will work. Anyone try this or here of someone doing this?
Title: Re: Spherical Robot Project MCU
Post by: spizzak on July 20, 2009, 11:48:37 AM: If your motor is fixed to the sphere it cant possibly cause the sphere to rotate. I'd be interested to see some sort of plan too if you could somehow post a drawing of some sort.

Cheers
Title: Re: Spherical Robot Project MCU
Post by: Razor Concepts on July 20, 2009, 12:46:25 PM: Quote from: spizzak on July 20, 2009, 11:48:37 AM
If your motor is fixed to the sphere it cant possibly cause the sphere to rotate. I'd be interested to see some sort of plan too if you could somehow post a drawing of some sort.

Cheers

Using inertia...?
Title: Re: Spherical Robot Project MCU
Post by: spizzak on July 20, 2009, 03:14:19 PM: Nevermind, I misread the part about the rod. I'm assuming the motor assembly rotates about the rod then?
Title: Re: Spherical Robot Project MCU
Post by: Joker94 on July 21, 2009, 05:51:44 AM: sounds good in thoery. Keep us posted, it sounds really interesting.