Tema: Re: CAM: (ne)vosvos
Autorius: Herkus
Data: 2013-10-22 15:16:05
ok, mintis gal ir nieko, nors elektronikoj mažai raukiu. Reikėtų 
schemos, kad raspberris gautų skaitmeninį signalą į I/O, kuomet degimas 
išjungtas. Tada išjungtų procesus tvarkingai ir galėtų sulaukti kol 
užlaikymo rėlė išjungs visiškai.

Turint omeny, tokias I/O charakteristikas:

You should keep the following limitations in mind when using the GPIO pins:
These are 3.3 volt logic pins. A voltage near 3.3 V is interpreted as a 
logic one while a voltage near zero volts is a logic zero. A GPIO pin 
should never be connected to a voltage source greater than 3.3V or less 
than 0V, as prompt damage to the chip may occur as the input pin 
substrate diodes (shown as parasitic FETs in Figure 1) conduct. There 
may be times when you may need to connect them to out-of-range voltages 
– in those cases the input pin current must be limited by an external 
resistor to a value that prevents harm to the chip. I recommend that you 
never source or sink more than 0.5 mA into an input pin.
To prevent excessive power dissipation in the chip, you should not 
source/sink more current from the pin than its programmed limit. So, if 
you have set the current capability to 2 mA, do not draw more than 2 mA 
from the pin.
Never demand that any output pin source or sink more than 16 mA.
Current sourced by the outputs is drawn from the 3.3 V supply, which can 
supply only 50 mA maximum. Consequently, the maximum you can source from 
all the GPIO outputs simultaneously is less than 50 mA. You may be able 
to draw transient currents beyond that limit as they are drawn from the 
bypass capacitors on the 3.3 V rail, but don't push the envelope! There 
isn't a similar limitation on sink current. You can sink up to 16 mA 
each into any number of GPIO pins simultaneously. However, transient 
sink currents do make demands on the board's bypass capacitors, so you 
may get into trouble if all outputs switch their maximum current 
synchronously.
Do not drive capacitive loads. Do not place a capacitive load directly 
across the pin. Limit current into any capacitive load to a maximum 
transient current of 16 mA. For example, if you use a low pass filter on 
an output pin, you must provide a series resistance of at least 
3.3V/16mA = 200 Ω.

On 2013-10-22 13:06, razumas wrote:
> uzlaikymo rele. 35 lt lemonoj.
>
> -- razumas "Herkus" <h@h.lt> wrote in message
> news:l45pjh$fnn$1@trimpas.omnitel.net...
>> >gal pasisemsi idëjø:
>> >http://forum.dashcamtalk.com/threads/where-did-you-mount-the-camera-post-your-pictures.502/
>> >
>> >Kadangi nerandu kamerø, kur matrica su objektyvu bûtø ant laido nuo paèio
>> >árenginio, tai vis audþiu minty pasidaryt DIY HD kamerà sujungus raspberry
>> >pi ir ~webcam. Vienintelis niuansas, kuris iki ðios sulaikë, reik
>> >sugalvot, kaip raspberry pi iðmaitint koká 30sek kai iðjungiamas degimas,
>> >kad sistema spëtø tvarkingai iðsijungti. Jei kas norës prisidët prie ðitos
>> >dalies sukonstravimo, tai programinë dalis galës bût mano.