[Dorset] Using a Raspberry Pi 'Headless' and Unattended
Hi, Clive has recruited me to help him at the Wimborne Model Town Railway ( http://www.wimborne-modeltown.com/the-model-town/model-railway/[1] ). His responsibility is controlling the lighting and we would like to use a Pi Zero to turn lights inside houses on and off at intervals and also to dim and brighten the main lights at 'dusk' and 'dawn'. We have a physical solution and the code is fairly trivial, but my main concern is the fact that once implemented, the Pi would have to run unattended for most of the time and also withstand having the power removed without a formal shutdown every evening (or if there is a power cut). Clearly, this would put the integrity of the data on the SD Card at risk. I think we have a solution, but before we rush off to do it, I'd appreciate your comments. The plan is to create a Live Tiny Core ( http://tinycorelinux.net/ports.html[2] ) distro containing the packages needed and the code to be run. We would install this on the SD Card and then make it Read-only. Each morning, the manager would then be able to power up the railway, which would bring up the Pi and start the program running. At the end of the day, the manager would then be able to turn off the supply without any risk to the SD Card. Can anyone see any problems with this approach or suggest a better way? -- Terry Coles [1] http://www.wimborne-modeltown.com/the-model-town/model-railway/ [2] http://tinycorelinux.net/ports.html -- Next meeting: Bournemouth, Tuesday, 2016-02-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] {Spam?} Using a Raspberry Pi 'Headless' and Unattended
On 11/01/16 12:19, Terry Coles wrote: > We have a physical solution and the code is fairly trivial, but my main > concern is the fact that once > implemented, the Pi would have to run unattended for most of the time and > also withstand having the > power removed without a formal shutdown every evening (or if there is a power > cut). Clearly, this would > put the integrity of the data on the SD Card at risk. > > > Can anyone see any problems with this approach or suggest a better way? > Terry, to be honest the description of the requirement suggests the Pi is overkill (IMHO), in my "intelligent" pump controller project I completed when my house was being assailed by flood wher I started with this approach but ended up with a v.cheap arduino board. The code being in on-board flash. Opps that takes me off-topic for a Linux group :-) Best regards, Simon -- Next meeting: Bournemouth, Tuesday, 2016-02-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] {Spam?} Using a Raspberry Pi 'Headless' and Unattended
On Monday 11 January 2016 12:35:40 Simon P Smith wrote: > On 11/01/16 12:19, Terry Coles wrote: > > We have a physical solution and the code is fairly trivial, but my main > > concern is the fact that once implemented, the Pi would have to run > > unattended for most of the time and also withstand having the power > > removed without a formal shutdown every evening (or if there is a power > > cut). Clearly, this would put the integrity of the data on the SD Card > > at risk. > > > > > > Can anyone see any problems with this approach or suggest a better way? > > Terry, to be honest the description of the requirement suggests the Pi > is overkill (IMHO), Funnily enough, that is exactly what I said to Clive! In fact his original solution consisted of a timer relay to just do the house lights and I thought that would be fine. However, when he started talking about controlling 'daylight', I accepted that a bit of intelligence would make things easier and certainly more flexible to allow additions to the functionality in the future. > in my "intelligent" pump controller project I completed when my house was > being assailed by flood wher I started with this approach but ended up with > a v.cheap arduino board. The code being in on-board flash. I also thought of Arduino, but I have no experience with it, whereas I have played around with the Pi. >From my recollection of the Arduino, from when we used one at work some years >ago, I think that we would need to buy some kit to interface to it. The nice thing about the Pi is that even now, everything has been done before and we can buy the hardware quite cheaply from CPC / element 14 > Opps that takes me off-topic for a Linux group :-) All comments gratefully received. -- Terry Coles -- Next meeting: Bournemouth, Tuesday, 2016-02-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] {Spam?} Using a Raspberry Pi 'Headless' and Unattended
On 11/01/16 12:35, Simon P Smith wrote: On 11/01/16 12:19, Terry Coles wrote: We have a physical solution and the code is fairly trivial, but my main concern is the fact that once implemented, the Pi would have to run unattended for most of the time and also withstand having the power removed without a formal shutdown every evening (or if there is a power cut). Clearly, this would put the integrity of the data on the SD Card at risk. Can anyone see any problems with this approach or suggest a better way? Terry, to be honest the description of the requirement suggests the Pi is overkill (IMHO), in my "intelligent" pump controller project I completed when my house was being assailed by flood wher I started with this approach but ended up with a v.cheap arduino board. The code being in on-board flash. Opps that takes me off-topic for a Linux group :-) Best regards, Simon -- I have a Stamp processor that could do it too, But Terry & Clive involved here know linux, and probably don't want to learn another language, and also want it supportable fo the future. I have always understood that the way to power down the R-Pi is to unplug it, and I have never heard about problems with the memory cards. I suggest to always have a backup card available in case of failure in any case. For headless operation it is advisable to use a fixed IP address in case you want to ssh into it, but on the basis of information given, it sounds like it is standalone and not networked. Cheers, Peter -- Next meeting: Bournemouth, Tuesday, 2016-02-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] {Spam?} Using a Raspberry Pi 'Headless' and Unattended
On Monday 11 January 2016 13:08:25 Peter Merchant wrote: > I have always understood that the way to power down the R-Pi is to > unplug it, and I have never heard about problems with the memory cards. Hmm. I'm fairly sure that the RPi Foundation recommend that you do a proper shutdown before pulling the plug. I have actually had problems with corrupt SD Cards, although I haven't established why yet. > I suggest to always have a backup card available in case of failure in > any case. There won't be anyone on site to swap the faulty card. Obviously, we will have a backup (or two or three), just in case. > For headless operation it is advisable to use a fixed IP address in case > you want to ssh into it, but on the basis of information given, it > sounds like it is standalone and not networked. There is no accessible network on site. -- Terry Coles -- Next meeting: Bournemouth, Tuesday, 2016-02-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] {Spam?} Using a Raspberry Pi 'Headless' and Unattended
On 11/01/16 13:21, Terry Coles wrote: On Monday 11 January 2016 13:08:25 Peter Merchant wrote: I have always understood that the way to power down the R-Pi is to unplug it, and I have never heard about problems with the memory cards. Hmm. I'm fairly sure that the RPi Foundation recommend that you do a proper shutdown before pulling the plug. I have actually had problems with corrupt SD Cards, although I haven't established why yet. Yes, it needs a proper shutdown. Two or three years back I designed a UPS to work with a Pi for a backup server, communicating over IIC, only to discover that the Pi IIC didn't implement pulse stretching. In the end it wasn't worth the effort considering an extra £60 bought an HP Microserver. So I agree the best way is any one of the embedded dev boards out there. FRDM-KL25Z gives you an Arm Cortex M0+ on a little board for a tenner. gcc for Arm and the Segger utilities then give a complete FOC Linux-based development platform. Cheers Tim -- Next meeting: Bournemouth, Tuesday, 2016-02-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] {Spam?} Using a Raspberry Pi 'Headless' and Unattended
On Monday 11 January 2016 14:17:09 t...@ls83.eclipse.co.uk wrote: > So I agree the best way is any one of the embedded dev boards out there. > FRDM-KL25Z gives you an Arm Cortex M0+ on a little board for a tenner. > gcc for Arm and the Segger utilities then give a complete FOC > Linux-based development platform. The only problem with that for me would be that I'd probably have to develop all the interfaces from scratch and go up a fairly steep (for me) learning curve wrt development on the KL25Z. As mentioned earlier, I am already familiar with the RPi and it comes with GPIO support out of the box with libraries for Python and C. In addition, the aftermarket has every interface to the RPi needed for a few tens of pounds. For example, CPC and others stock a relay card specifically designed to interface to the RPI. This could be used to turn the lights on and off. To dim the LEDs a PWM script will run a low power LED straight off the GPIO pins or for higher powers, the aftermarket can supply there too with a MOSFET interface driven by the same GPIO pin. I have to think about whoever picks this up in the future and the RPi makes knowledge transfer so much easier (especially with the rising generation who are now using them in schools :-) ) -- Terry Coles -- Next meeting: Bournemouth, Tuesday, 2016-02-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] {Spam?} Using a Raspberry Pi 'Headless' and Unattended
** Terry Coles [2016-01-11 18:53]: > On Monday 11 January 2016 14:17:09 t...@ls83.eclipse.co.uk wrote: > > So I agree the best way is any one of the embedded dev boards out there. > > FRDM-KL25Z gives you an Arm Cortex M0+ on a little board for a tenner. > > gcc for Arm and the Segger utilities then give a complete FOC > > Linux-based development platform. > > The only problem with that for me would be that I'd probably have to develop > all the interfaces from > scratch and go up a fairly steep (for me) learning curve wrt development on > the KL25Z. > > As mentioned earlier, I am already familiar with the RPi and it comes with > GPIO support out of the box > with libraries for Python and C. In addition, the aftermarket has every > interface to the RPi needed for a > few tens of pounds. > > For example, CPC and others stock a relay card specifically designed to > interface to the RPI. This could > be used to turn the lights on and off. To dim the LEDs a PWM script will > run a low power LED straight > off the GPIO pins or for higher powers, the aftermarket can supply there too > with a MOSFET interface > driven by the same GPIO pin. > > I have to think about whoever picks this up in the future and the RPi makes > knowledge transfer so much > easier (especially with the rising generation who are now using them in > schools :-) ) ** end quote [Terry Coles] I'm in pretty much the same position, I'm familiar with PCs and hence the Raspberry Pi, but haven't had the time to get my head around the Arduino more electronics oriented way of doing things. It probably wouldn't take too long, but with so much else to do I haven't found the time yet - even my Pi projects aren't progressing at the moment! Anyway, working on the basis of using a Raspberry Pi, it seems to me that the key requirement would be to detect the loss of power and shutdown. Clearly this needs some form of battery or capacitor to provide enough time before complete loss of power. There are a number of similar projects out there if you are wanting to do some soldering, etc., but an easier alternative might me something like the UPS PIco (1) or the Pi UPS (2). (1) http://www.modmypi.com/raspberry-pi/breakout-boards/pi-modules/ups-pico (2) https://www.pi-supply.com/product/pi-ups-uninterrupted-power-supply-raspberry-pi/?v=79cba1185463 I've not used either, but they look interesting: The UPS PIco is a standard Hat format, includes a battery, has a stackable header for other addons, software based RTC and supports auto power down on power loss, so looks to have everything ready to go. It also charges the battery. The Pi UPS is a bit more expensive and uses standard batteries (not supplied) and looks to require a bit of coding to read the GPIO to do the shutdown. I can't find anything about charging, although using a standard battery may be easier to replace - but then they'd need replacing more frequently I guess. Actually the UPS PIco looks quite interesting - I mustn't add to my Pi collection, I've already got plenty to play with that hasn't been explored yet! -- Paul Tansom | Aptanet Ltd. | https://www.aptanet.com/ | 023 9238 0001 Vice Chair, FSB Portsmouth & SE Hampshire Branch | http://www.fsb.org.uk/ = Registered in England | Company No: 4905028 | Registered Office: Ralls House, Parklands Business Park, Forrest Road, Denmead, Waterlooville, Hants, PO7 6XP -- Next meeting: Bournemouth, Tuesday, 2016-02-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
