Personally i would tap in at the 12V supply for the cigarette lighter. Go to a shop and buy an in car micro USB adaptor, take it apart. solder it up in parallel with the back of the cigarette lighter socket.Mariuspe wrote:guys,
who could advise how everything should be connected? Idea is to use RPI in a car running on car battery only when ignition is ON. Problem: after turning ignition OFF, RPI should run for enough time e.g. 30-60 secs to shutdown properly. Means it has:
1. to track when power is cut off
2. has to have its autonomous rechargeable power enough for 30-60secs. One idea is using capacitors.
Can it be achieved with capacitors? If so, what components should be used for that? I have no clue on this electric part:)
interesting, but not sure if I understood specification correctly: will it run on battery if USB camera is connected to RPI?PiGraham wrote:This might be interesting:
http://www.simbits.nl/portfolio/raspber ... er-shield/
Your site gets blocked by antivirus:mausberry wrote:I currently have a car power supply for the Pi that connects to the ignition, +bat and -bat and safely shuts down the Pi when it senses that the ignition has been off (then cuts power to the Pi).
Current draw for a powered down pi can range from 100ma to 250ma. Just a rough estimate, but at 100ma it would take about 200-something hours to kill a car battery.. But yes, I'm pretty sure you can find 12v always on, acc (ignition 12v), and a negative right behind the stereo of most if not all cars.. Just check the wiring diagram.gummibear wrote: ↑Sat Oct 29, 2016 11:40 pmI know I'm necro-ing this, but I say this in case someone else stumbles across this thread. As someone who has installed many radios and aftermarket gauges in cars, the radio wiring harness gives you both an always-on wire, and an ignition switched wire. (admittedly, I haven't bought a new car or radio in ten years.) At any rate, if there's no always-on for some reason, it's easy to run a wire to the battery, but make SURE to put a fuse in it. probably a pretty low amp one. I can't imagine there not being an ignition switch on the wire somewhere.
TL;DR: look up radio install guides for your car. they are extremely easy to find. they will give you the wires you need. then add a circuit with relay, and delay.
edit: in fact, maybe all you need is a voltage stepdown on the "ignition on" wire to a pin on gpio. when a background program senses zero volts it shuts down the pi after some time. however, that would not solve current draw in the "shutdown" state.