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by Hugh Jarse
Tue Aug 14, 2012 7:45 am
Forum: Automation, sensing and robotics
Topic: Raspberry Pi goes mobile, WP7 joins the ride
Replies: 10
Views: 2274

Re: Raspberry Pi goes mobile, WP7 joins the ride

Thought I could share with you people my latest project for the Pi :D Read all about it at my blog, http://blog.fagerbakke.net/2012/8/13/raspberry-pi-goes-mobile,-wp7-joins-the-ride.aspx. What I've done is removing the "brains" of a toy car and replaced it with a Pi connected to a motor controller....
by Hugh Jarse
Mon Aug 13, 2012 2:07 pm
Forum: Automation, sensing and robotics
Topic: RF Bitbanger ported to Raspberry Pi
Replies: 91
Views: 46117

Re: RF Bitbanger ported to Raspberry Pi

So you buy a TX433N, connect it to a GPIO, do some software stuff, and you can control devices via 433.92 Mhz? If so ... Ouch! See what I've done: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=37&t=11280 http://eva-quirinius.blogspot.nl/2012/07/google-calendar-raspberry-pi-and-lights.html I had...
by Hugh Jarse
Sat Aug 11, 2012 9:42 pm
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12138

Re: 240 v mains controller

I have finally managed to put the initial documentation for this project together. It is at:

http://www.mhr.me.uk/projects/socketcontrol.html
by Hugh Jarse
Wed Aug 01, 2012 9:03 am
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12138

Re: 240 v mains controller

Just to say that I have completed my prototype. I have four sockets which can be switched on or off, over the internet from a web page. Each sockets state is displayed as an LED icon on the web page (green = on, grey = off). These icons represent the real state of power output, rather than being fak...
by Hugh Jarse
Wed Aug 01, 2012 7:33 am
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12138

Re: 240 v mains controller

But sometimes you just want an easy solution - and there are various main sockets that can be switched via USB -Gordon I agree. If you just want to achieve the end goal then there are products already available for most things. However if you are more interested in the journey, and want to play at ...
by Hugh Jarse
Tue Jul 31, 2012 8:00 am
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12138

Re: 240 v mains controller

I had considered using relays but ruled them out for this application because : 1) direct switching of mains and routing 240VAC via the board could be hazardous especially if the Pi is prone to moving around by its cables and you try to reposition/catch/move it by hand. Probably not suitable for a c...
by Hugh Jarse
Thu Jul 26, 2012 10:47 am
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12138

Re: 240 v mains controller

For reference, the level changer I used was an open collector NPN ("2N3904) with a 4K7 pull up resistor, and a 470 ohm base resistor (3.3v/470 = 0.7ma, GPIO is limited to 0.8ma). For now, I am using the 12v cell from the remote control to provide the 12v.
by Hugh Jarse
Wed Jul 25, 2012 11:01 pm
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12138

Re: 240 v mains controller

Just to say that I have put a prototype together which does this and turns 4 sockets on or off from a single GPIO pin (via a transistor). In the end I ditched the remote control because I could not get my signal to coexist with the encoder on the PCB. Instead I went for one of these http://proto-pic...
by Hugh Jarse
Tue Jul 24, 2012 8:26 am
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12138

Re: 240 v mains controller

If you are going the RF route to control mains, you need to interface to a transmitter. The maplin remote control is one way, but you will need to step the voltage up to make this workable. The Pi GPIO digital lines are 0-3.3v. To drive the maplin kit (R433A transmitter) you need 0-5v minimum, and i...
by Hugh Jarse
Mon Jul 02, 2012 12:47 pm
Forum: Troubleshooting
Topic: Peformance Debian “squeeze” Scratch
Replies: 3
Views: 886

Re: Peformance Debian “squeeze” Scratch

Thanks for your reply.

I will give the wheezy beta a try.
by Hugh Jarse
Mon Jul 02, 2012 10:32 am
Forum: Troubleshooting
Topic: Peformance Debian “squeeze” Scratch
Replies: 3
Views: 886

Re: Peformance Debian “squeeze” Scratch

OK, so is it expected that these programs should run so slowly, or do I have a problem ?
by Hugh Jarse
Sun Jul 01, 2012 2:58 pm
Forum: Troubleshooting
Topic: Peformance Debian “squeeze” Scratch
Replies: 3
Views: 886

Peformance Debian “squeeze” Scratch

Recently received my Raspberry PI and installed the Debian “squeeze” (19/04/2012) onto an SD card. The system runs up fine and I logged in and ran startx to bring up LXDE, I attempted to show my youngest child the Scratch environment. It is really nice that people have taken the time to provide some...
by Hugh Jarse
Mon Mar 19, 2012 3:23 pm
Forum: Other projects
Topic: Cheap Robot Starting Point
Replies: 7
Views: 2218

Re: Cheap Robot Starting Point

<t>Thanks for your reply. The idea of being configurable via a web server brings RPi into the loop on the basis of relative ease of hosting a web server on it. However, that aside, I am thinking more and more that this particular type of project might be better suited to an Arduino board (i.e. non R...
by Hugh Jarse
Sun Mar 18, 2012 11:53 am
Forum: Other projects
Topic: Cheap Robot Starting Point
Replies: 7
Views: 2218

Re: Cheap Robot Starting Point

[Duplicate post removed]
by Hugh Jarse
Sun Mar 18, 2012 11:53 am
Forum: Other projects
Topic: Cheap Robot Starting Point
Replies: 7
Views: 2218

Re: Cheap Robot Starting Point

<r>Just had a dig around and found this link, which deals with the opto feedback in the way that andriodcave suggests above.<br/> <br/> This uses a BeagleBone/Chipkit pair of boards to drive the Big Trak Junior, and allows it to be programmed over a web interface hosted on the BeagleBone. Nice to se...
by Hugh Jarse
Sun Mar 18, 2012 10:59 am
Forum: Other projects
Topic: Cheap Robot Starting Point
Replies: 7
Views: 2218

Re: Cheap Robot Starting Point

I guess you get what you pay for, and these wont climb vertically , however the drive wheels do in fact have a rubber ring around the centre section.
by Hugh Jarse
Fri Mar 16, 2012 11:41 pm
Forum: Other projects
Topic: Cheap Robot Starting Point
Replies: 7
Views: 2218

Re: Cheap Robot Starting Point

<r>This "toy" looks interesting as a working motorised platform for a robot project.<br/> <br/> It costs around £15 and uses two motors.<br/> <br/> <br/> <br/> <URL url="http://www.amazon.co.uk/CuteBi.....k_h_b_cs_4">http://www.amazon.co.uk/CuteBi.....k_h_b_cs_4</URL><br/> <br/> The only wrinkle I c...
by Hugh Jarse
Sun Mar 11, 2012 11:24 am
Forum: General discussion
Topic: Programming GPIO
Replies: 7
Views: 3913

Re: Programming GPIO

Thanks for your replies.
by Hugh Jarse
Sat Mar 10, 2012 11:29 pm
Forum: General discussion
Topic: Programming GPIO
Replies: 7
Views: 3913

Re: Programming GPIO

The FAQ suggests the datasheet is not available yet - is this still the case?

Meanwhile it looks as if inotify may be one way of generating events in C or Python, when a file is changed (i.e. a GPIO input changes).
by Hugh Jarse
Sat Mar 10, 2012 11:01 pm
Forum: General discussion
Topic: Programming GPIO
Replies: 7
Views: 3913

Re: Programming GPIO

<r>Thanks for your reply.<br/> <br/> It seems that output will be done by redirecting data to a logical file  :<br/> <br/> <URL url="http://www.raspberrypi.org/archives/500">http://www.raspberrypi.org/archives/500</URL><br/> <br/> which is great, and seems straight forward.  Has anyone seen any info...
by Hugh Jarse
Sat Mar 10, 2012 9:12 pm
Forum: General discussion
Topic: Programming GPIO
Replies: 7
Views: 3913

Re: Programming GPIO

<t>Can anyone shed any light on what (if any) programming interfaces will be available for reading and writing to the GPIO hardware - e.g. will it be accessible from say python.<br/> <br/> Is it the case that we will need to await drivers from the open source community, or is there something already...

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