Raspberry - restart

On a sunny day (Mon, 29 Dec 2014 08:41:18 +0100) it happened gm wrote in :

My experience.

On a sunny day (Tue, 30 Dec 2014 01:17:07 +1100) it happened Chris Jones wrote in :

I dunno, I have something like this for an other project from ebay:

I use a Microchip MCP73831 charger chip, been running now daily charge / discharge to about 70% for several month. In standby you would not discharge that deep, lipos last a long time (low self discharge).

I was thinking I would probably run a script on the raspi to monitor a gpio pin, and call poweroff if some GPIO pin is low, that would orderly shut it down. Most Microchip PICs (no I do not work for them) have brown out detection logic and some have internal reference and comparators.. while [ 1 ] do if( GPIO something ) then /sbin/poweroff fi ; maybe sleep to save cycles, use usleep in C sleep 1 done

And have the PIC set the GPIO pin on low mains / DC.

Well, I have several raspis in use now, occasionally I accidently shut of the power to one, it should not do a lot of damage really, you may lose some data in buffers. Make backups.

The general idea is it is easy to quickly put together some circuit IF you are a designer. For the masses I really do not know what they want, but it should probably be much cheaper than a new raspi.

The Pi is very sensitive to power; the newer A+ and B+ are a little better.

As with Jan, I use a home-grown UPS for a number of Pi projects.

It drives the Pi with a buck/boost +5V converter (from Pololu Electronics). The converter has a wide input range, from 2.7 to about

The converter is fed from external DC, and from a Lipo cell hooked to a Lipo charger

A handful of Schottky diodes feed power from the external DC input and the Lipo output so that power to the buck/boost converter either comes from external DC or the Lipo, similar to the Juice4Halt idea.

With a 5AH Lipo, I can move things around easily, and tolerate multi-hour power interruptions.

Just using the buck/boost converters to feed the Pi eliminates a lot of issues with undervoltage, sags, and spikes.

On 30/12/2014 01:43, Jan Panteltje wrote: [...]

I did not mean to imply that someone in China can't succeed in posting something to you once. It is a different matter when using this in a product in your own country, and having to lie every day when the courier asks you explicitly if you are sending lithium batteries. Whilst in a personal capacity that may be OK, for a business it may be more hassle than using a supercapacitor (or alkaline cell for that matter).

I would be interested to know how resilient supercaps and lipos are when left in a hot car in the sun a few times. I have heard that mobile phones often don't survive this

For things that are supposed to be appliances, e.g. ADSL modem/routers, that would not be acceptable, so they have to make the software better, such that it cannot brick itself just because you turned off the mains.

It is the labour of going to the device and changing the SD card for a not-yet-corrupted one, and the cost of downtime that I would like to avoid.

The Raspberry Pi is restarting because when power is applied via the micro USB port, the resettable fuses on the board trip. This is a very annoying/irritating issue with this board. A workaround is to feed in extra power through one of the two normal(NOT micro) USB ports. Then, if a USB hub is is connected to the other normal USB port, BOTH a USB keyboard/mouse may be used, without any issues, and the Ethernet port will have sufficient power for the network connection. Why this issue has not been fixed by the designers, is unclear. Hope this helps.

It doesn't have a DC power connector? Powering high wattage devices through a usb cable isn't very bright to start with IMO.

On a sunny day (Tue, 30 Dec 2014 13:22:09 +1100) it happened Chris Jones wrote in :

It is a Varta battery, IIRC Varta is based in Germany, if you have a business and want a thousand I'm sure they know how to ship it to you. Probably cheaper per 1000 too.

Well, some people seem to have problems. I had it mess up an SDcard repeatedly, until I found it it was simply full, and I made a mistake putting the image on that card without resetting the true size. The new card was actually a few sectors smaller than the one the old image came from. Not all sdcards have the same real size. I moved to 16 GB cards and fixed the ext4 size (there is some function in the setup file for that). Since then it does not corrupt the card if you pull the plug. Backups saved me!!! I improved my backup method to prevent this happening again by tgz the 2 partitions, and then for new cards simply use fdisk to make partitions and mkfs to make a filesystem, and then untarring the backups in each partition. This is easily said here, but probably already beyond what many raspi users will know about. But one should REALLY look at some errors made by ONE SELF before declaring the thing defective. Like some other poster here mentioned, ext4 is really solid, probably why I use reiserfs almost everywhere ;-) World is full of dualities.

BTW I'v been looking at the price of super caps of 25 Farads and more on ebay after looking at that thing you linked to, I will stay with my lipos :-)

Yes, I am sure that I can buy the batteries, but selling products containing them is a hassle. There is some special accreditation that you can get to be a professional battery export packer or something. I'm sure a battery company can afford to have such a trained and licenced person on their payroll but I don't want to have to. I know that the size of the cells can be in the range that is oficially exempt from regulation, but many people and companies apply policies more strict than the actual IATA regulations, and having repeated arguments with them can cost a lot of time, even if you are right.

Chris

On a sunny day (Tue, 30 Dec 2014 22:34:56 +1100) it happened Chris Jones wrote in :

The Raspberry Pi device's primary power input is via a micro USB port(as I mentioned in my earlier message). There are two regular USB ports for connecting USB peripheral devices. The primary micro USB power input is very sensitive, because of resettable fuses. At boot time, with a HDMI/ composite video monitor, Ethernet cable and USB mouse/keyboard connected, the board naturally sucks power and the resettable fuses trip. So, additional power has to be supplied via one of the regular USB ports.

you could try adding a power-on-reset chip.

I've seen automobile parts fail (an ordinary electronic blinker relay with 105 degree electrolytic capacitors)

absolutely they can, just not too often. 1 in 10000 power cycles is probably acceptable.

or short out the resettable fuse, it doesn't seem very useful. one with a reasonable current limit has too high on-resistance, one with a higher rating isn't going to trip unless you have big short and USB should be current limited anyway

-Lasse