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 8215 Posts Member #: 90 Post Whore Somewhere around Swindon |
2nd Jun, 2012 at 10:45:18am
right reading through this i am even more confused!
Crystal Sound Audio said:
Why wolfie...you should have your name as Fuckfaceshithead ! "A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools."-Douglas Adams |
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 (2)[/url] by [url=https://www.flickr.com/photos/150672766@N03/]Rod Sugden[/url], on Fli) 5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
2nd Jun, 2012 at 11:16:09am
An additional board to both power it from 12V and to handle the serial interface to the MS2/3.
Schrödinger's cat - so which one am I ??? |
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8215 Posts Member #: 90 Post Whore Somewhere around Swindon |
2nd Jun, 2012 at 01:01:16pm
ok cool, i am easily confused lol
Crystal Sound Audio said:
Why wolfie...you should have your name as Fuckfaceshithead ! "A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools."-Douglas Adams |
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 608 Posts Member #: 1106 Post Whore Hungerford, Berks |
4th Jun, 2012 at 08:27:09am
Here's the Rpi in action.
’77 Clubman build thread
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114 Posts Member #: 9645 Advanced Member South Wales |
4th Jun, 2012 at 12:16:35pm
Looks good Graham - loading time is not too bad I think.
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608 Posts Member #: 1106 Post Whore Hungerford, Berks |
4th Jun, 2012 at 01:15:08pm
That's the plan, but I'm struggling on that part. X server does not load automatically, so I have had to add auto login and a command to load X server, but that happens later in the boot cycle than the other distro's I have played with, hence I need to find a way to do it.
Edited by Graham T on 4th Jun, 2012. ’77 Clubman build thread
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Forum Mod  1927 Posts Member #: 1761 Stalker Bristol |
4th Jun, 2012 at 01:32:10pm
Good effort so far Graham.
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
4th Jun, 2012 at 02:12:47pm
Carl,
Schrödinger's cat - so which one am I ??? |
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608 Posts Member #: 1106 Post Whore Hungerford, Berks |
4th Jun, 2012 at 07:01:38pm
Carl,
Edited by Graham T on 4th Jun, 2012. ’77 Clubman build thread
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Forum Mod 1927 Posts Member #: 1761 Stalker Bristol |
4th Jun, 2012 at 10:06:43pm
Righto, I'll get back to you tomorrow Graham. |
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857 Posts Member #: 1778 Post Whore Northants |
23rd Nov, 2012 at 01:54:49pm
Any other news on the Pi front??
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
23rd Nov, 2012 at 03:49:18pm
A bit of a co-incedence you asking at this moment in time...
Schrödinger's cat - so which one am I ??? |
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1267 Posts Member #: 831 Post Whore Montreal, Canada |
23rd Nov, 2012 at 04:05:19pm
Could you not power it directly from the car battery and turn it off when it detects a key off? This way you don't have to worry about stalls or failed start but only about the key position. And if you don't want to connect directly to the battery you could look into adding a supercap to power it for the shutdown period.
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
23rd Nov, 2012 at 04:20:14pm
On 23rd Nov, 2012 jbelanger said:
Could you not power it directly from the car battery and turn it off when it detects a key off? This way you don't have to worry about stalls or failed start but only about the key position. And if you don't want to connect directly to the battery you could look into adding a supercap to power it for the shutdown period. Jean, Been through the logic, all possibilities and probabilities, even considered the MS2 might not start the engine immediately (heaven forbid) and battery voltage may drop below the 5V reg chip's requirement (it's not an LDO in this case because of the current required) and if you add all the possibilities up, the sequence is quite complex. In your scenario, it's the reboot/TS load time if you attempted multiple engine re-starts (repetitive key on/ key offs) that is the killer on the logic front. One of the guys on the RPI wikis did suggest a supercap when they were talking about a UPS for the RPI (instead of a lead/acid battery) to cover the shutdown - seems a bit OTT (and pricey) compared to logic :) But I'm open to suggestions as usual :) Schrödinger's cat - so which one am I ??? |
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Forum Mod 1927 Posts Member #: 1761 Stalker Bristol |
23rd Nov, 2012 at 04:24:27pm
Why would you be turning the key to position zero to restart, Rod?
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
23rd Nov, 2012 at 04:36:09pm
On 23rd Nov, 2012 Carl S said:
Why would you be turning the key to position zero to restart, Rod? Unless you need to flash the MS2 of course, that's the only situation I can think of where you would need to cycle the barrel switch all the way off and all the way back again... but even then, I would have thought you would be in a position where you could wait for the pi to shutdown properly and start back up. Carl, You are absolutely right, most of the "logic" can be done by myself and Graham's right hand on the ignition switch.... 
But, partly from my background in nuclear engineering, I prefer to take the "end user" - and that includes me - out of the equation. No offence intended, I just prefer a solution that can't be "broken". Schrödinger's cat - so which one am I ??? |
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 8604 Posts Member #: 573 Formerly Axel Podland |
23rd Nov, 2012 at 04:38:43pm
Any room on that new board for a switched/regulated 12v power supply for a monitor? Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
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Forum Mod 1927 Posts Member #: 1761 Stalker Bristol |
23rd Nov, 2012 at 04:39:36pm
Fair enough Rod :) I know where you're coming from as well!
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1267 Posts Member #: 831 Post Whore Montreal, Canada |
23rd Nov, 2012 at 04:39:56pm
Rod,
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
23rd Nov, 2012 at 05:08:21pm
On 23rd Nov, 2012 jbelanger said: Yes, that is the worst case scenario we are trying to cover, it actually seems the most likely one to happen. We want a 60 second window (Graham has got boot and TS load to less than that (without overclocking)) so that is our aim.
Rod, Unless you're saying that the RPi isn't even up yet when the power is cycled so it wouldn't even have a chance to control the power source which could be an issue. On 23rd Nov, 2012 jbelanger said:
But you still have this issue with what you're proposing. I think I can get around that one in simple CMOS logic chips (with a bit of C/R timing) unless I try to cover a loss of battery during any of the possible vents - then I would still need a supercap or something similar
Schrödinger's cat - so which one am I ??? |
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1267 Posts Member #: 831 Post Whore Montreal, Canada |
23rd Nov, 2012 at 05:20:45pm
What you could do is use a 555 to keep power on for the first 60 seconds then use an output on the RPi. When you see a key off, wait a certain amount of time and shut down. This way you don't care about the user power cycles when starting and you don't have to determine if there has been a stall or other specific events.
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857 Posts Member #: 1778 Post Whore Northants |
23rd Nov, 2012 at 05:26:00pm
This is one thing that concerns me, the fact that the "recommended" way to shutdown is just to unplug the power as stated on the manufacturers website.
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
23rd Nov, 2012 at 05:54:33pm
On 23rd Nov, 2012 sturgeo said:
This is one thing that concerns me, the fact that the "recommended" way to shutdown is just to unplug the power as stated on the manufacturers website. A good point - but there are quite a few posts in the various RPi wikis about SD card corruption even though they originally said just unplug it. In fairness we've only experienced it once (I'll let Graham explain if he sees this) but you wouldn't unplug a desktop PC if you could shut it down properly ??? So it just seems more sensible to invoke a proper shutdown routine if it's doeable (which we think it is). On 23rd Nov, 2012 sturgeo said:
What OS are you running Rod? I noticed you were running a web browser in one of your pictures, do you know if plugins like flash & silverlight can be made to work? Again. I'll let Graham explain, I'm the hardware person, not the software
EDITs - typos Edited by Rod S on 23rd Nov, 2012. Schrödinger's cat - so which one am I ??? |
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
23rd Nov, 2012 at 06:08:44pm
On 23rd Nov, 2012 Paul S said:
Any room on that new board for a switched/regulated 12v power supply for a monitor? Paul, Not entirely sure what you mean. The monitors Graham and I are using are 12V anyway with a wide range of input voltage (all around 12V) but I could easily add a filter and switch it from the RPi supply logic - actually that seems like a good idea now you mention it.... Schrödinger's cat - so which one am I ??? |
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
23rd Nov, 2012 at 06:18:37pm
On 23rd Nov, 2012 jbelanger said:
What you could do is use a 555 to keep power on for the first 60 seconds then use an output on the RPi. When you see a key off, wait a certain amount of time and shut down. This way you don't care about the user power cycles when starting and you don't have to determine if there has been a stall or other specific events. The only problem is if a user turns power off after a while and turns power back up after your time out period; this will mean the RPi is in shut down mode when power goes back on. But that should be a very rare event and I don't see how you can avoid having a similar scenario with any solution. Jean Jean, The various logic sequences are quite numerous..... but like in your second paragraph, it's the "very rare event" that will destroy the logic :) Schrödinger's cat - so which one am I ??? |
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