dccfoux
Posts: 3
Joined: Fri Sep 21, 2012 1:55 am

How Can I Start Learning Robotics By Using My Pi

Sun Sep 23, 2012 7:37 pm

Hello everyone, I have just ordered my RPi and cant wait for it to arrive. I was just wondering, especially with the Gertboard out, how can I use it for robotics. I have been wanting to start learning with an arduino but once I found the RPi and saw that people were using it for similar projects, that I would just purchase the Pi. So yeah, what should I do to learn how?

emcsquirreled
Posts: 90
Joined: Sat Aug 18, 2012 1:26 am
Location: Portland, OR USA
Contact: Website

Re: How Can I Start Learning Robotics By Using My Pi

Sun Sep 23, 2012 9:16 pm

dccfoux wrote:Hello everyone, I have just ordered my RPi and cant wait for it to arrive. I was just wondering, especially with the Gertboard out, how can I use it for robotics. I have been wanting to start learning with an arduino but once I found the RPi and saw that people were using it for similar projects, that I would just purchase the Pi. So yeah, what should I do to learn how?
What sort of robot are you wanting to build? What are you already good at? When learning something new with computers or electronics, I generally pick a project I like and just run with it until I either finish it or find a new project. With a little more information, I could make a project suggestion... Good luck with the Pi!
Linux -- The operating system with a CLUE (Command Line User Environment)
--
FTC Team 4508
E=MC Squirreled
emcsquirreled.github.com

simplesi
Posts: 2327
Joined: Fri Feb 24, 2012 6:19 pm
Location: Euxton, Lancashire, UK
Contact: Website

Re: How Can I Start Learning Robotics By Using My Pi

Sun Sep 23, 2012 9:29 pm

The Gertboard isn't the one for robotics as it only has 1 motor output :(

http://elinux.org/RPi_Expansion_Boards# ... otic_Board would be more useful as its sold as a Robotics Board (plus its smaller/lighter/cheaper and available :) )

And Simon Monk's new board
http://www.raspirobot.com/

looks just the job but its not available yet :(

Simon
Seeking help with Scratch and I/O stuff for Primary age children
http://cymplecy.wordpress.com/ @cymplecy on twitter

emcsquirreled
Posts: 90
Joined: Sat Aug 18, 2012 1:26 am
Location: Portland, OR USA
Contact: Website

Re: How Can I Start Learning Robotics By Using My Pi

Sun Sep 23, 2012 10:10 pm

On the board question, I am using the GPIO pins straight from bare metal code. Adafruit sells a nice ribbon cable/breakout pin combo which I will probably get after my code works a little better. If you want to drive motors from the GPIO, all you would need is a relay-powered H-bridge. Let us know what you end up doing! :)
Linux -- The operating system with a CLUE (Command Line User Environment)
--
FTC Team 4508
E=MC Squirreled
emcsquirreled.github.com

dccfoux
Posts: 3
Joined: Fri Sep 21, 2012 1:55 am

Re: How Can I Start Learning Robotics By Using My Pi

Sun Sep 23, 2012 10:37 pm

emcsquirreled wrote:
dccfoux wrote:Hello everyone, I have just ordered my RPi and cant wait for it to arrive. I was just wondering, especially with the Gertboard out, how can I use it for robotics. I have been wanting to start learning with an arduino but once I found the RPi and saw that people were using it for similar projects, that I would just purchase the Pi. So yeah, what should I do to learn how?
What sort of robot are you wanting to build? What are you already good at? When learning something new with computers or electronics, I generally pick a project I like and just run with it until I either finish it or find a new project. With a little more information, I could make a project suggestion... Good luck with the Pi!
Well I am good at web coding and visual basic. And just about anything that has to do with computers outside of the coding languages I did not mention. I would like to learn from scratch how to build lets say a robot with a Pi, ya know stuff in that general area.

simplesi
Posts: 2327
Joined: Fri Feb 24, 2012 6:19 pm
Location: Euxton, Lancashire, UK
Contact: Website

Re: How Can I Start Learning Robotics By Using My Pi

Sun Sep 23, 2012 10:44 pm

I would like to learn from scratch how to build lets say a robot with a Pi, ya know stuff in that general area.
I'm starting an after-school club for 10 Year olds on 1st Oct - I'll be blogging about it - so feel free to follow :)

We've jump started by buying a Magician Chassis (2 motors, wheels and a flat plate) to mount an RPi on - although Session 1 will be putting it together :)

Simon

PS
If you want to drive motors from the GPIO, all you would need is a relay-powered H-bridge
Well If you only want the motors to turn one way - all you need is a couple of transistors/diodes or a 37p ULN2003 buffer chip :)
Seeking help with Scratch and I/O stuff for Primary age children
http://cymplecy.wordpress.com/ @cymplecy on twitter

User avatar
tedhale
Posts: 114
Joined: Thu Sep 20, 2012 4:52 pm
Location: Williamsburg, VA, USA
Contact: Website

Re: How Can I Start Learning Robotics By Using My Pi

Sun Sep 23, 2012 10:56 pm

emcsquirreled wrote:On the board question, I am using the GPIO pins straight from bare metal code. Adafruit sells a nice ribbon cable/breakout pin combo which I will probably get after my code works a little better. If you want to drive motors from the GPIO, all you would need is a relay-powered H-bridge. Let us know what you end up doing! :)
While a simple H bridge using relays will allow control of a motor, for a robot you will find that method will behave somewhat crudely due to a lack of power control. If you build an H bridge using power transistors and diodes (you should be able to google a design) the power to the motor can be very finely controlled by using a pulse and varying the duty cycle (i.e. how long the pulse is on vs. off)
- Ted B. Hale
http://raspberrypihobbyist.blogspot.com

User avatar
tedhale
Posts: 114
Joined: Thu Sep 20, 2012 4:52 pm
Location: Williamsburg, VA, USA
Contact: Website

Re: How Can I Start Learning Robotics By Using My Pi

Sun Sep 23, 2012 11:01 pm

dccfoux wrote:
emcsquirreled wrote:
dccfoux wrote:Hello everyone, I have just ordered my RPi and cant wait for it to arrive. I was just wondering, especially with the Gertboard out, how can I use it for robotics. I have been wanting to start learning with an arduino but once I found the RPi and saw that people were using it for similar projects, that I would just purchase the Pi. So yeah, what should I do to learn how?
What sort of robot are you wanting to build? What are you already good at? When learning something new with computers or electronics, I generally pick a project I like and just run with it until I either finish it or find a new project. With a little more information, I could make a project suggestion... Good luck with the Pi!
Well I am good at web coding and visual basic. And just about anything that has to do with computers outside of the coding languages I did not mention. I would like to learn from scratch how to build lets say a robot with a Pi, ya know stuff in that general area.
If that's where you are starting from, then you will need to learn the basics of electronics and how to solder. Even when you use mostly pre-made parts you still end up having to solder connectors.
- Ted B. Hale
http://raspberrypihobbyist.blogspot.com

User avatar
tedhale
Posts: 114
Joined: Thu Sep 20, 2012 4:52 pm
Location: Williamsburg, VA, USA
Contact: Website

Re: How Can I Start Learning Robotics By Using My Pi

Sun Sep 23, 2012 11:10 pm

simplesi wrote:
I would like to learn from scratch how to build lets say a robot with a Pi, ya know stuff in that general area.
I'm starting an after-school club for 10 Year olds on 1st Oct - I'll be blogging about it - so feel free to follow :)

We've jump started by buying a Magician Chassis (2 motors, wheels and a flat plate) to mount an RPi on - although Session 1 will be putting it together :)

Simon

PS
If you want to drive motors from the GPIO, all you would need is a relay-powered H-bridge
Well If you only want the motors to turn one way - all you need is a couple of transistors/diodes or a 37p ULN2003 buffer chip :)
I am also blogging about my work with the Pi. I am targeting the beginner to intermediate hobbyist, so it may be above the level of a 10 year old (but you never know!)
Hopefully it will be useful to someone.

http://raspberrypihobbyist.blogspot.com/
- Ted B. Hale
http://raspberrypihobbyist.blogspot.com

emcsquirreled
Posts: 90
Joined: Sat Aug 18, 2012 1:26 am
Location: Portland, OR USA
Contact: Website

Re: How Can I Start Learning Robotics By Using My Pi

Mon Sep 24, 2012 3:31 pm

I mentioned the H-bridge as an example of how easy a fully-functional robot could be. More advanced designs would clearly need better circuitry (and I am a better coder than an electrician, so sorry for being so ignorant :? ).

Regardless of what is used, a simple chassis (my homebrew bot lives in a sandwich-sized tupperware container), two small DC motors, the Pi, and some batteries all wired into a piece of perfboard should get you started.

When I started, I knew the code and not the hardware, so my first bot skipped the programming part, and was instead controlled by a comparator chip and two pairs of photoresistors, which allowed it to follow a line. Thus, I got to learn very basic soldering and circuit design, without worrying about any code. Now that I have done that, I have worked on some more complicated designs with a focus on the coding and autonomous behaviour. Knowing people who like to build but can't code to save their life is quite the perk! :D
Linux -- The operating system with a CLUE (Command Line User Environment)
--
FTC Team 4508
E=MC Squirreled
emcsquirreled.github.com

User avatar
tedhale
Posts: 114
Joined: Thu Sep 20, 2012 4:52 pm
Location: Williamsburg, VA, USA
Contact: Website

Re: How Can I Start Learning Robotics By Using My Pi

Mon Sep 24, 2012 6:34 pm

I know the feeling. I am surrounded by engineers that love to build stuff but can not program to save their life. Funny how they let them program but they won't let me engineer. Of course, that could be a good thing :)
- Ted B. Hale
http://raspberrypihobbyist.blogspot.com

User avatar
alexeames
Forum Moderator
Forum Moderator
Posts: 2869
Joined: Sat Mar 03, 2012 11:57 am
Location: UK
Contact: Website

Re: How Can I Start Learning Robotics By Using My Pi

Mon Sep 24, 2012 9:20 pm

Couldn't you use a Gertboard to drive servos with the Atmega? I think the Gertboard can control at least 12 servos. Or are they no good for robots?
Alex Eames RasPi.TV, RasP.iO

emcsquirreled
Posts: 90
Joined: Sat Aug 18, 2012 1:26 am
Location: Portland, OR USA
Contact: Website

Re: How Can I Start Learning Robotics By Using My Pi

Tue Sep 25, 2012 1:32 am

I don't know about the Gertboard in specific, but servos are quite useful in applications which require lower torque and higher precision. Thus, something like an arm would be done with servos (or pneumatics or hydraulics, but I will ignore those options right now). DC motors, on the other hand, are big, power-hungry, high-speed contraptions. It all depends on the specific application. I've seen small bots build off of servos, but anything which is big, heavy, or strong is running a DC motor.
Linux -- The operating system with a CLUE (Command Line User Environment)
--
FTC Team 4508
E=MC Squirreled
emcsquirreled.github.com

0117blocky
Posts: 43
Joined: Mon Apr 30, 2012 8:03 am

Re: How Can I Start Learning Robotics By Using My Pi

Tue Sep 25, 2012 9:53 am

I would not rule out the gertboard for controlling motor drivers.The microcontroller on board is capable of handling more than one motor driver (at least 4).
The advantage of the gertboard it will be community supported, meaning lots of help and useful experiments plus a driver has been written for it to interface with the RPI.

I would agree there are boards more suited for robotics but to me it's a question of the level of support.
Take a look at this article. (I will still use external flyback diodes even though he appears to have left them out.)
http://www.starlino.com/motor_driver.html

Return to “General discussion”