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by pygmy_giant
Sun May 20, 2012 10:55 pm
Forum: Automation, sensing and robotics
Topic: Bare Metal Robots
Replies: 33
Views: 7900

Re: Bare Metal Robots

God bless you sir - I doubt I can give you any advice but I would be happy to help with testing when my pi arrives

RE: the hatchet approach, I am looking at Puppi as / when / if it becomes available as it runs in RAM and could be faster than an OS that constantly accesses the SD card...?
by pygmy_giant
Sun May 20, 2012 10:43 pm
Forum: Automation, sensing and robotics
Topic: Bare Metal Robots
Replies: 33
Views: 7900

Re: Bare Metal Robots

Is there any tool / method that could track the modules / objects called in the process of executing my code to enable me to decide which daemons to slay?
by pygmy_giant
Sun May 20, 2012 10:38 pm
Forum: Automation, sensing and robotics
Topic: Bare Metal Robots
Replies: 33
Views: 7900

Re: Bare Metal Robots

I have found many ARM RTOS's mentioned on the web but none Pi compatible - I have been told that it would be easiest to adapt one built for the ARM11, but I do not have the expertese. I can see value in the de-bloat approach - wonder which distro would be best to start with... ...alternatively there...
by pygmy_giant
Sun May 20, 2012 10:24 pm
Forum: Automation, sensing and robotics
Topic: Bare Metal Robots
Replies: 33
Views: 7900

Re: Bare Metal Robots

Thanks again - you seem to have answered alot of my question ... I think I can also monkey about with 'latencies' ? I've been told that I can use chrt -r -p 99 [pid] to set a process's priority ( http://www.cyberciti.biz/faq/h.....y-process/ ) and that I could also tell a program to lock all it's me...
by pygmy_giant
Sun May 20, 2012 10:15 pm
Forum: Automation, sensing and robotics
Topic: Bare Metal Robots
Replies: 33
Views: 7900

Re: Bare Metal Robots

Thanks Dave_G_2 - again, interesting. I need to study that - I am grateful for your input. I need to study Linux - I am a Linux 'noob' - at the risk of sounding too demanding: I don't want bloat - I want to create a real-time control system for my robot. I only ever want one user space program to ru...
by pygmy_giant
Sun May 20, 2012 9:49 pm
Forum: Automation, sensing and robotics
Topic: Bare Metal Robots
Replies: 33
Views: 7900

Re: Bare Metal Robots

Interesting. Given that I am committed to using Frank's kernel and his I2C driver kernel objects, but need nothing else, how can I get his kernel to then execute my own robot control binary? Is there a filename that I can give it that garuntees the kernel will run it? Should I call it 'init' ? http:...
by pygmy_giant
Sun May 20, 2012 7:49 pm
Forum: Automation, sensing and robotics
Topic: Bare Metal Robots
Replies: 33
Views: 7900

Re: Bare Metal Robots

Thanks for explaining about the kernel objects.

I guess I do really want to write my own 'mini os' - what should I call it so that the kernel loads it?

Is there any reason I can't write it in C++ and compile it with GCC ?
by pygmy_giant
Sun May 20, 2012 12:10 am
Forum: Automation, sensing and robotics
Topic: Bare Metal Robots
Replies: 33
Views: 7900

Bare Metal Robots

Hi I'm counting the days until my pi arives (10) and want to use it in a robot. I therefore only need input via the SD card on boot and output to the GPIO pins. So why bother with a full operating system? I understand the Pi loads the firmware on power-up which then loads the kernel (or any binary c...
by pygmy_giant
Fri May 18, 2012 1:13 am
Forum: Other projects
Topic: Linux device drivers for Rapberry Pi on-board I/O
Replies: 97
Views: 54321

Re: Linux device drivers for Rapberry Pi on-board I/O

Hi - GadgetUk - OWFS - elegant and intruiging - will research further... I am embarrassed to admit I am a linux virgin - can you help me? I am guessing you are using either command line linux commands or bash script (is that the same thing) ? Are you using Arch Linux or Debian? The reason I ask is t...
by pygmy_giant
Fri May 18, 2012 12:19 am
Forum: Other projects
Topic: Bare metal Raspberry Pi
Replies: 23
Views: 6740

Re: Bare metal Raspberry Pi

I want to build a robot and only need: 1) input via SD card 2) output via GPIO pins Frank Buss has modified the kernel to incorporate I2C modules - http://www.frank-buss.de/tmp/kernel.img so..... what else do i need? ..... theoretically, if I had Frank's source code, could I just add to it to progra...
by pygmy_giant
Wed May 16, 2012 12:26 pm
Forum: Other projects
Topic: Linux device drivers for Rapberry Pi on-board I/O
Replies: 97
Views: 54321

Re: Linux device drivers for Rapberry Pi on-board I/O

Aha - understand better now - expect more questions though - thanks in advance...
by pygmy_giant
Tue May 15, 2012 10:56 pm
Forum: Automation, sensing and robotics
Topic: Balancing Robot
Replies: 183
Views: 50656

Re: Balancing Robot

Yes - I may be forced to modify my ambitions :¬/ Thinkning maybe some kind of pivoting 'head' with rotating ultrasonic sensor ...? Guess that's a long way off yet ... still soldering up the battery pack and waiting for my Pi ... I have been looking at these (ebay) parts for motor control: 2007062540...
by pygmy_giant
Tue May 15, 2012 10:35 pm
Forum: Other projects
Topic: Linux device drivers for Rapberry Pi on-board I/O
Replies: 97
Views: 54321

Re: Linux device drivers for Rapberry Pi on-board I/O

Sorry for exposing my ignorance and impatience - re-read the thread and figured out that the expander board Frank used was just for testing and that the kernel is available here: http://www.frank-buss.de/tmp/kernel.img Not sure yet what to do with it or the config file posted here: http://pastebin.c...
by pygmy_giant
Tue May 15, 2012 10:41 am
Forum: Other projects
Topic: Linux device drivers for Rapberry Pi on-board I/O
Replies: 97
Views: 54321

Re: Linux device drivers for Rapberry Pi on-board I/O

Thank you again to those who have been working on this. My Pi is due due in 2 weeks and I am keen to start building a robot from the multitude of affordable I2C modules available. How can Joe Public get his hands on the kernel / driver and send instructions to the I2C bus from inside a language such...
by pygmy_giant
Sun May 13, 2012 7:50 pm
Forum: Automation, sensing and robotics
Topic: Balancing Robot
Replies: 183
Views: 50656

Re: Balancing Robot

Ahh- filtering... if you could point me to some formulas I would be grateful. I wonder if magnetometer data could also be used as an additional reference point to factor out drift - useful for navigation regardless. I read somewhere that its also good to put the accelerometer between the axles to re...
by pygmy_giant
Thu May 10, 2012 8:48 pm
Forum: Automation, sensing and robotics
Topic: Balancing Robot
Replies: 183
Views: 50656

Re: Balancing Robot

<r>Those are impressive looking lego machines – wish I had a job that enabled me to publicly admit to playing with lego in adult company without feeling embarrased. My official excuse for getting a pi is that I'm trying to interest my son in robotics, but to be honest, I'm hoping he'll loose interes...
by pygmy_giant
Wed May 09, 2012 11:17 pm
Forum: Other projects
Topic: Qt 5 Alpha
Replies: 4
Views: 1542

Re: Qt 5 Alpha

<t>At the risk of sounding a pedant, I would be less than impressed if someone literally 'rocked my socks off' – it strikes me as a time consuming and repetative process. In addition, I suspect that the geometry of a sloth''s feet would soon put holes in any fabric footwear making it inpractical - w...
by pygmy_giant
Wed May 09, 2012 10:37 pm
Forum: Automation, sensing and robotics
Topic: Balancing Robot
Replies: 183
Views: 50656

Re: Balancing Robot

<r>Thanks hunternet93 the article states<br/> <br/> "Regardless of the operating system and computer used on your robot project, unless it is a very tightly controlled “real-time” or embedded system, you will not be able to count on very precise time intervals. Most general purpose operating systems...
by pygmy_giant
Wed May 09, 2012 10:22 pm
Forum: Other projects
Topic: Linux device drivers for Rapberry Pi on-board I/O
Replies: 97
Views: 54321

Re: Linux device drivers for Rapberry Pi on-board I/O

God bless you boffins – there is a debate on another thread about whether linux + I2C gyros/accellerometers could handle balancing a robot on 2 wheels. I for one am following your progress with interest – you are doing valuabe work…
by pygmy_giant
Wed May 09, 2012 9:56 pm
Forum: Automation, sensing and robotics
Topic: Balancing Robot
Replies: 183
Views: 50656

Re: Balancing Robot

<r>Hi<br/> <br/> Rew – thanks for the practical suggestion. I don"t know enough about linux (yet) to write my own bits and bobs but am open to learning and suggestion.<br/> <br/> Gordon H – I have been banging on about the need for a minimal distro / RTOS for Pi projects like this on other topic thr...
by pygmy_giant
Tue May 08, 2012 10:15 pm
Forum: Automation, sensing and robotics
Topic: Balancing Robot
Replies: 183
Views: 50656

Re: Balancing Robot

<r>perhaps – be careful though: <URL url="http://www.bbc.co.uk/news/uk-e.....d-14167868">http://www.bbc.co.uk/news/uk-e.....d-14167868</URL><br/> <br/> I2C seems to be the way to go... affordable gyro/accelerometer/magnetometer modules on ebay (god bless the chinese). Also an I2C combined h-bridge a...
by pygmy_giant
Tue May 08, 2012 9:37 pm
Forum: Automation, sensing and robotics
Topic: Balancing Robot
Replies: 183
Views: 50656

Re: Balancing Robot

<t>Hmm – could work, that"s how skool kids show off on their mountain bikes round our way….<br/> <br/> … another way could be to have a 4x4 chassis (no diffs or pivoting wheels – just tank type steering) eg:<br/> <br/> <br/> <br/> This could then climb a wall with its front wheels like those popular...
by pygmy_giant
Tue May 08, 2012 1:15 am
Forum: Automation, sensing and robotics
Topic: Balancing Robot
Replies: 183
Views: 50656

Re: Balancing Robot

<t>Thanks for the encouragement Mr Richards<br/> <br/> I thought of using a two wheeled chassis with a castor - then the robot could work either horizontaly on 3 wheels or verticaly on 2!<br/> <br/> Dropping down from two wheels to 3 would be easy, but I cant think of a way to get up from 3 to 2 ......
by pygmy_giant
Mon May 07, 2012 11:54 pm
Forum: Other projects
Topic: Straw poll for home print cardboard case: What printer do you have?
Replies: 32
Views: 12035

Re: Straw poll for home print cardboard case: What printer do you have?

if its clear you could put it over a printed pattern and trace with a craft knife
by pygmy_giant
Fri May 04, 2012 11:56 pm
Forum: Automation, sensing and robotics
Topic: Balancing Robot
Replies: 183
Views: 50656

Re: Balancing Robot

<t>Forgot to say that loop returns to step 1 after 7.<br/> <br/> NB – a 2 axis gyro/accelerometer would allow safe cornering as relative wheel speeds could could be adjusted to prevent vehicle tipping over sideways – 3 axis sensors could measure inclines and declines – this data could be used alongs...

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