A530 external power - page 3 - Hotwire! Hardware Mods, Accessories and Insights - CHDK Forum
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A530 external power

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Offline ahull

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Re: A530 external power
« Reply #20 on: 16 / November / 2013, 17:29:49 »
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An update on the alarm clock idea is long overdue on my part, partly due to the winter weather I suspect.

I hope to get back to this little project soon. I have a couple of ideas, the first is simply to OR together the outputs from the two LED drivers to switch on a relay. This would only give us 1 minute to take a picture (the alarm bleeps and flashes for 1 minute). The enhanced version would require me to figure out how to allow the camera to keep the power on for as long as it needs. I am hoping to use an opto-coupler to detect the lens being deployed, as a trigger to keep the power on for longer.

I also started to build a four channel remote camera trigger.

It uses a cheap'n cheerful "IC2262/2272 4 Channel Wireless RF Remote Control Transmitter kits  w/ Receiver" (stick that phrase in ebays search to see what I am talking about). It looks like this... ...and a four port hub.

The tranciever cost a mere 2.65 GBP (not including the battery).

Its still on the breadboard at the moment, but I will also post the details of that if and when it makes it in to a serviceable condition.

The idea is pretty simple, I power the receiver from the hub, which is in turn powered from the +5V from a  USB port (or the solar charger I have mentioned previously).

The four outputs from the receiver will each toggle to +5V when the respective button is pressed on the transmitter, and I intend to simply connect one of these outputs to the +5v of each of the  four USB ports on the USB hub (having cut the existing track to the +5V line), then use CHDK's USB triggering ability to fire the camera(s).
« Last Edit: 16 / November / 2013, 17:46:34 by ahull »
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Offline waterwingz

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Re: A530 external power
« Reply #21 on: 16 / November / 2013, 17:37:11 »
Quote from: ahull on 16 / November / 2013, 17:29:49
I also started to build a four channel remote camera trigger.  It uses a cheap'n cheerful "IC2262/2272 4 Channel Wireless RF Remote Control Transmitter kits  w/ Receiver" like this...
I've played with these a bit.  The receiver toggles state each time a button in pressed on the transmitter - making shooting a "two press" operation.    It would be simple to add a new input module to the USB remote code that would handle these devices more conventionally (i.e. one shot per press). This sort of application is why I rewrote the USB remote code to be easily extensible.
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Offline ahull

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Re: A530 external power
« Reply #22 on: 16 / November / 2013, 17:50:07 »
There are actually several variants of this type of module, using different versions of the transmitter/receiver IC, which either toggle or are pulsed. I think the version I have pulses (according to the designation on the chip), but so far it has only made it as far as the breadboard, and has yet to be powered up.  ::) Not enough hours in the day at the moment. I'll attach a link to the chip spec when I get a moment.

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Offline waterwingz

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Re: A530 external power
« Reply #23 on: 16 / November / 2013, 17:57:00 »
Quote from: ahull on 16 / November / 2013, 17:50:07
There are actually several variants of this type of module, using different versions of the transmitter/receiver IC, which either toggle or are pulsed. I think the version I have pulses (according to the designation on the chip), but so far it has only made it as far as the breadboard, and has yet to be powered up.  ::) Not enough hours in the day at the moment. I'll attach a link to the chip spec when I get a moment.
Took a little search but I knew I'd seen this used before : http://chdk.setepontos.com/index.php?topic=5383.msg84416#msg84416
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Ported :   A1200    SD940   G10    Powershot N    G16
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Offline ahull

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Re: A530 external power
« Reply #24 on: 16 / November / 2013, 18:59:03 »
Some of these gadgets use the PT2262/72 which as far as I can tell toggles.

The variant I have uses the SC2272M4 which is a momentary output variant. There is a L4 (latch) M4 (momentary) and T4 (toggle) version.

http://www.sc-tech.cn/en/2272en.htm
« Last Edit: 16 / November / 2013, 19:03:35 by ahull »
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Offline DapperGent

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Re: A530 external power
« Reply #25 on: 23 / November / 2013, 14:08:40 »
This is just an idea: how about using an SC2272 T4 (toggle version) remote with your alarm clock, then your alarm clock just has to give a signal output long enough to toggle the camera to switch on power at a set time eg dawn or dusk?
Also I guess it might be possible to use another alarm clock to switch it off again at a set time too to conserve power? What do you think?
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Offline VladimirSlavik

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Re: A530 external power
« Reply #26 on: 24 / November / 2013, 06:22:28 »
If you're still talking about A530, this might help with manipulating the power button...

https://plus.google.com/u/0/100078254555312524768/posts/e2oxLoiRjLB

Short version: In front of power button are two pads. Connecting the left pad to +Vbat = button pressed.
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Offline Microfunguy

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Re: A530 external power
« Reply #27 on: 24 / November / 2013, 06:33:17 »
Quote from: VladimirSlavik on 24 / November / 2013, 06:22:28
If you're still talking about A530, this might help with manipulating the power button...

I did that earlier this year with an A620.
I fitted two gold-plated 1mm sockets into the body for the external timer to connect two.

Unfortunately, the socket is prone to interference pick-up and can trigger randomly.

David
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Offline VladimirSlavik

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Re: A530 external power
« Reply #28 on: 24 / November / 2013, 16:07:20 »
Hm. A pure speculation would be that as it is probably a digital i/o, you could use either a pull-down resistor, or drive it with a logic gate (or equivalent circuit)...
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Offline ahull

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Re: A530 external power
« Reply #29 on: 25 / November / 2013, 00:43:25 »
Quote from: VladimirSlavik on 24 / November / 2013, 16:07:20
Hm. A pure speculation would be that as it is probably a digital i/o, you could use either a pull-down resistor, or drive it with a logic gate (or equivalent circuit)...

The use of a logic level input would certainly be possible, however you would need to determine with a 'scope or multimeter, exactly what that level would need to be, and you would also probably be advised to use a diode to isolate your login input from the input generated by pressing the button (otherwise you risk frying your input device if someone presses the power button when your device is connected).

The power circuitry we know about uses a variant of the Power manager, PWM controller MB39C303
From memory, having read the datasheet for this family a while back, this can be switched on with a fairly broad range of input voltages. This does not necessarily apply to cameras where we have no knowledge of the power supply schematics. These models may, or may not use a variant of this controller. 

There is however a simpler method of switching on the camera, which works for all of the devices I have tested. The camera will power on, if the power button is held down mechanically, prior to switching on the external PSU. You can use a bit of tape, modelling clay or whatever to hold down the button, without any surgery being necessary on the camera.

Once powered on,  the camera then behaves normally despite the button being continuously held down.
 
The problem then becomes a much simpler (and in many senses safer) one of controlling the external PSU. This can be done with a relay or mosfet, controlled by the external trigger (PIR, alarm clock, pressure pad, microcontroller or whatever).
 
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