help needed in determining materials list

I didn't understand the exact requirement, did you intend the RPI to gracefully power off when the vehicle is not in operation?

If so, there are alternate ways that do not require the LiPo and step-up DC-DC converter - the sleepy pi would then likely meet the need.

Well, that's part of it. I also want to ensure no vehicle battery drain when the system is not in use. In addition, I need some mechanism to ensure the RPi is getting clean power in the hostile power environment present in a car. That was the thought behind the LiPO. The LiPO is meant to ensure a clean stream of power to the RPi no matter what the power condition is in the vehicle.

The requirements are:

1) Ensure that the system can completely power off such that there is not drain on the automotive battery.

2) Ensure a clean and steady power supply to the RPi.

3) Provide a mechanism to allow the RPi to shut itself down gracefully and then "wake up" when the vehicle key is switched to the "run" position. Note the IGN wire in my drawing. That's what starts the whole process.

The sleepy pi may be an option. I am unsure if it the entire system can be completely shut down...meaning does the arduino stay powered on the whole time? If so, that would cause a drain on the automotive battery. Lastly, I see that it provides the power management I'm looking for; however, I really need to be able to fend off the spikes, brownouts, and sustained voltage craziness in the vehicle. I would still need some kind of battery to provide the consistent power I'm looking for...correct?

Sat-Nav and in car entertainment equipment operate from the vehicle battery. They contain processors too, and a LiPo is not needed for cleanliness with these devices.

The sleepy pi website specifies "Extend RPi battery life from hours -> weeks / months" so I'm confident it won't drain the vehicle battery when powered off gracefully (which

is what the sleepy pi does). Basically relays, LiPo's and step-up converters are not needed - saves a lot of effort!

You should take steps to ensure the input won't exceed 17V (the sleepy pi limit) - perhaps using a varistor, TVS or both.

Sat-Nav and in car entertainment equipment operate from the vehicle battery. They contain processors too, and a LiPo is not needed for cleanliness with these devices.

The sleepy pi website specifies "Extend RPi battery life from hours -> weeks / months" so I'm confident it won't drain the vehicle battery when powered off gracefully (which

is what the sleepy pi does). Basically relays, LiPo's and step-up converters are not needed - saves a lot of effort!

You should take steps to ensure the input won't exceed 17V (the sleepy pi limit) - perhaps using a varistor, TVS or both.

I have been experiencing power-related problems with my RPi project. Log messages harvested from the SD card suggest power-related issues that cause a bunch of horrible things to happen like the network interface to stop functioning. Over and over again I have come to realize that the RPi seems to be sensitive to in-vehicle power fluctuations. This is the largest impediment to my project. If I'm wrong, do you have any ideas what I may be experiencing and why? For example, when the RPi is running off of the vehicle battery and the vehicle is started, the only LED on the Pi that lights up is the second one and it stays red. Nothing else happens. The device will not function until I completely pull the power for several seconds and then re-apply power.

Hi Shabaz, yeah the proposal is some what over complicated. Also the relays would be too slow switching the power to and from the Pi so really the LiPo would be redundant.

I would suggest using a 5V 1-2A Switching regulator with  an inhibit/enable pin to control it powered directly from the permanent 12V.

you would then need to work on the logic in such away that if the IGN 12V isn't present then the Regulator is inhibited thus will not switch on. This will need to have a bypass probably based on say a 555 monostable which is periodically reset by the RPI's GPIO.

A script running will keep the power on after the key is removed only long enough to shut down cleanly....Voila!

Hi John,

Exactly, I agree, it was unnecessary complications!

We've not even asked what he wants to do and we are engineering the finer points of the design.

Can  Arch Nemesis explain what he wants to achieve with the Raspberry Pi in the car?

On 8/11/2014 10:37 a.m., John Alexander wrote:

We've not even asked what he wants to do and we are engineering the

finer points of the design.

Can  Arch Nemesis explain what he wants to achieve with the Raspberry Pi

in the car?

h5.

 

--

To view any images and attachments in this post, visit:

http://www.element14.com/community/message/130595

 

And another thing. This is the support forum for the Cadsoft Eagle

software.

This is totally the wrong place for this discussion. Please take it

elsewhere.

Thank you

Warren

I am very sorry. I completely missed where this was. Is it possible for an admin to move this to the appropriate place?

I'm assuming you want to know about the project? Not just the power management side of it? My project is related to telematics. It started as geolocation technology but has grown in scope to include much more. The Pi has been very useful for this.

Just ask Element14jamie to move it or just ask the question again

The link doesn't work. however the project sounds very interesting. Please re ask the question on the Raspberry PI forum.

I for one would like to  see what you are intending for your project. Please send us a link to the question.

Better still start a blog post and get some points for it

Just ask Element14jamie to move it or just ask the question again

Thanks for the tip. However, I ran into a problem. Since Element14jamie is not following me, I can't PM him. See the attached photo. Any ideas?