Go to advanced search

by Hugh Jarse
Fri Nov 15, 2013 11:54 pm
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12043

Re: 240 v mains controller

Hi Hugh, Your work fascinated me so much that I decided to write an alternative web interface for it. The one I saw was pretty basic and I hope you haven't yet started work on improvements. :roll: What I made today has a few features that make your system even more usable. Additions: 1: Before acce...
by Hugh Jarse
Fri Nov 15, 2013 11:46 pm
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12043

Re: 240 v mains controller

Hi stuart to prevent the inversion you should set the line #define k_Invert 1 to #define k_Invert 0 and recompile. Always best to confirm it is doing what you expect with a scope. The compilation instructions are in the header and are basically gcc -o sckctrl sckctrl.c -l bcm2835 Obviously this assu...
by Hugh Jarse
Tue Nov 12, 2013 7:08 am
Forum: Automation, sensing and robotics
Topic: 433mhz cheap power plugs
Replies: 14
Views: 9108

Re: 433mhz cheap power plugs

by Hugh Jarse
Wed Nov 06, 2013 3:57 pm
Forum: Automation, sensing and robotics
Topic: compatible 433Mhz USB transceivers?
Replies: 30
Views: 65523

Re: compatible 433Mhz USB transceivers?

Ditto here for the Ciseco kit. I find XRFs are good, and the frequency is configurable. http://shop.ciseco.co.uk/xrf-wireless-rf-radio-uart-rs232-serial-data-module-xbee-shape-arduino-pic-etc/ I have just completed a project which uses one of these on the Raspberry Pi and and one on each of three AT...
by Hugh Jarse
Wed Nov 06, 2013 3:49 pm
Forum: Automation, sensing and robotics
Topic: Room by Room central heating control
Replies: 31
Views: 33190

Re: Room by Room central heating control

Interesting project. I have a couple of comments.

1. Do you intend to implement some form of hysteresis to prevent the solenoids chattering?
2. I am not sure which solenoids you have chosen but there are latching solenoids available which only require a pulse when the state is to be changed.
by Hugh Jarse
Sun Nov 03, 2013 11:49 am
Forum: Automation, sensing and robotics
Topic: SCAMP : Supervisory Control And Monitoring Platform.
Replies: 0
Views: 760

SCAMP : Supervisory Control And Monitoring Platform.

SCAMP : Supervisory Control And Monitoring Platform. A hobby SCADA/automation platform using a single frequency radio link to communicate to multiple devices with TDMA. Implemented using Raspberry Pi as the master terminal unit and using ATMega328 microcontrollers as remote terminal units. A simple ...
by Hugh Jarse
Wed Oct 30, 2013 12:02 am
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12043

Re: 240 v mains controller

I have made some updates since I first posted the remote mains socket controller info. The link now contains an update to the source code to work with the latest versions of the bcm2835 library, an example of using cron for automatic timed switching of sockets on/off, and update the circuit diagram,...
by Hugh Jarse
Sat Feb 02, 2013 10:37 am
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12043

Re: 240 v mains controller

Please note that because this solution works by bit banging and producing waveforms based on a given clockspeed, it is unlikely to work reliably if the RPi has been overclocked. Waveform patterns were based on the recommended 700MHz clock speed settings. It addition the original implementation of t...
by Hugh Jarse
Sat Feb 02, 2013 9:56 am
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12043

Re: 240 v mains controller

Hugh, I suspect that the increased interest is because of an article in the latest MagPi about remote controlled sockets. I've yet to get your solution working - not sure why and have been distracted by trying to get a couple of other things working. In your wiring diagram, you are using pin 26 as ...
by Hugh Jarse
Sun Jan 13, 2013 10:29 pm
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12043

Re: 240 v mains controller

The feedback could be easily added via other methods like a single chip wireless (wifi/bluetooth/zigbee) client or wireless arduino if you prefer with 5v usb power attached to the power socket. The limitation is only your imagination. I am just coming to the end of the project which followed the RF...
by Hugh Jarse
Sun Jan 13, 2013 10:23 pm
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12043

Re: 240 v mains controller

Yes it uses GPIO07, the opposite corner pin from 3v3 pin.

Probably the best thing to do is to scope the pin it to see what is happening.

The other thing is that 3.3v is right on the limit of the transmitter - the datasheet quotes 3 - 12v, and the original remote control used 12v too.
by Hugh Jarse
Sun Jan 13, 2013 5:35 pm
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12043

Re: 240 v mains controller

That is elegant, but a very different project. The trade off for no components is that the the transmitter has 1/80th of the power and there is no state feedback. A very nice bit of engineering nevertheless.
by Hugh Jarse
Sun Jan 13, 2013 10:06 am
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12043

Re: 240 v mains controller

Due to recent interest in this project (not sure why this has just happened) I have started adding some of the downloads to the project page. This should reduce requests for these now, but any questions feel free to contact me.

http://www.mhr.me.uk/projects/RPiProjects.html
by Hugh Jarse
Fri Nov 16, 2012 3:22 pm
Forum: Raspberry Pi OS
Topic: Ram Disk and SCADA
Replies: 3
Views: 1232

Re: Ram Disk and SCADA

I have resolved this now.
Since /tmp is in ram, this is a good place to read and write the file.
by Hugh Jarse
Fri Nov 16, 2012 10:17 am
Forum: Raspberry Pi OS
Topic: Ram Disk and SCADA
Replies: 3
Views: 1232

Ram Disk and SCADA

I am developing a SCADA system based around a Raspberry Pi host and ATMega328 remote terminal units communicating over UHF. The state of the IO channels of each remote terminal unit is polled and stored in a file on the Raspberry Pi SD Card every second. This is read by web browsers in order to disp...
by Hugh Jarse
Thu Oct 18, 2012 8:37 am
Forum: Automation, sensing and robotics
Topic: 240 v mains controller
Replies: 28
Views: 12043

Re: 240 v mains controller

I have made a small change to the project weblog to add the construction of a shield from vero to mount the external prototype board inside the Raspberry Pi box. http://www.mhr.me.uk/projects/socketcontrol.html However feeding back a DC signal from each socket to indicate the switched state does not...
by Hugh Jarse
Sat Sep 29, 2012 1:45 pm
Forum: Automation, sensing and robotics
Topic: Software implementation of HT12E encoder
Replies: 6
Views: 3428

Re: Software implementation of HT12E encoder

I have sent some information to your email address.
by Hugh Jarse
Wed Aug 22, 2012 4:58 pm
Forum: Automation, sensing and robotics
Topic: RPi oscilloscope
Replies: 14
Views: 9080

Re: RPi oscilloscope

DexOS wrote: Heres some of my tuts, using assembly macros to make a basic/arduino like language for bare metal coding.
http://www.dex-os.com/DexBasic/DexBasic.htm
Interesting project. Made me think about doing this for Forth for some reason :-)
by Hugh Jarse
Tue Aug 21, 2012 4:33 pm
Forum: Automation, sensing and robotics
Topic: Will An Ebay Relay Board work with the pi?
Replies: 53
Views: 17153

Re: Will An Ebay Relay Board work with the pi?

I interpreted the

"Each one needs 15-20mA Driver Current."

as an external interface requirement for the driving the board, rather than a power (supply) requirement.

Hopefully this will be fine then.
by Hugh Jarse
Tue Aug 21, 2012 3:55 pm
Forum: Automation, sensing and robotics
Topic: RPi oscilloscope
Replies: 14
Views: 9080

Re: RPi oscilloscope

Timing is going to be a big issue the PI doesn't have an RT clock or timing chips so calculating the frequency would be problematic if not inaccurate. Richard S. I think this point is well made. To do this kind of application where you want the display to tell the truth about the outside world, you...
by Hugh Jarse
Tue Aug 21, 2012 3:48 pm
Forum: Automation, sensing and robotics
Topic: Will An Ebay Relay Board work with the pi?
Replies: 53
Views: 17153

Re: Will An Ebay Relay Board work with the pi?

My recollection of the current limitations was that you cannot exceed more than 51ma total GPIO output without affecting the voltage regulator. In addition, I think a maximum of 16ma per pin is stated. Either of these would make me concerned enough to add an interface layer between the GPIO and this...
by Hugh Jarse
Tue Aug 21, 2012 3:28 pm
Forum: Automation, sensing and robotics
Topic: Monnitoring a solar powered pi
Replies: 2
Views: 1409

Re: Monnitoring a solar powered pi

If you cant add ADC, isnt there some trick you can do with a set of zener diodes. The granularity you get is dictated by the range of zeners you can get or wish to use so this may be a non starter. Other options include using an ADC chip (e.g. via Gertboard), or using a microcontroller to do this (I...
by Hugh Jarse
Thu Aug 16, 2012 10:10 am
Forum: Automation, sensing and robotics
Topic: Making an on/off switch for 12v
Replies: 9
Views: 24852

Re: Making an on/off switch for 12v

Hi guys, What I'm basically after, is a RPi replacement of this 12v timer . You can do this with a simple npn transistor circuit. The process is roughly as follows 1. Work out the maximum current needed (add a little 10-20% for good measure), assuming this is less than a few hundred mA, a transisto...
by Hugh Jarse
Wed Aug 15, 2012 8:51 am
Forum: Automation, sensing and robotics
Topic: RPi controlled central heating
Replies: 37
Views: 25004

Re: RPi controlled central heating

Probably a good idea to understand the basics of your circuit (e.g Y plan, S plan etc) but in short the roomstat is usually used to drive the motor in the valve (depending on your CH setup), see http://wiki.diyfaq.org.uk/index.php?tit ... and_Zoning.
by Hugh Jarse
Tue Aug 14, 2012 12:43 pm
Forum: Automation, sensing and robotics
Topic: RPi controlled central heating
Replies: 37
Views: 25004

Re: RPi controlled central heating

Hi I've been using my RPi as a car computer and that's easy - just software! But electronics is like magic to me. I want to make my RPi control my heating system. It seems the easiest way is to take out my room thermostat (which is mechanical and just breaks the 240 V circuit when the temperature e...

Go to advanced search