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Battery third (temp) terminal as multipurpose analogue input

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Re: Battery third (temp) terminal as multipurpose analogue input
« Reply #190 on: 06 / August / 2018, 05:22:13 »
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If you would provide a dummy battery with a shunt, could you measure the current consumption of the camera with the AD converter?
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Re: Battery third (temp) terminal as multipurpose analogue input
« Reply #191 on: 02 / January / 2019, 06:48:13 »
Hi,
 I have a question about using the temperature terminal as a remote trigger. The option should appear under the Remote Parameters section of the menu, right? I have an Ixus 75, chdk 1.4.1 from August 2018, and there is no option mentioning anything about using the battery terminal as a remote trigger.
 Is it only applicable to newer cameras?
thanks,
Andrew

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Offline reyalp

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Re: Battery third (temp) terminal as multipurpose analogue input
« Reply #192 on: 02 / January / 2019, 16:06:00 »
Hi,
 I have a question about using the temperature terminal as a remote trigger. The option should appear under the Remote Parameters section of the menu, right? I have an Ixus 75, chdk 1.4.1 from August 2018, and there is no option mentioning anything about using the battery terminal as a remote trigger.
 Is it only applicable to newer cameras?
thanks,
It needs to be enabled per port, which we generally only do after someone has tested it. If you post which Canon firmware your camera has, I can post a test build.
Don't forget what the H stands for.

Re: Battery third (temp) terminal as multipurpose analogue input
« Reply #193 on: 02 / January / 2019, 18:46:02 »
Hi reyalp,
 the firmware version is ixus75_sd750-102a, please don't rush to build it as I need (lots of) time to make a 3 terminal battery (with each terminal positioned precisely enough),
many thanks for helping,
andrew


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Offline reyalp

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Re: Battery third (temp) terminal as multipurpose analogue input
« Reply #194 on: 03 / January / 2019, 02:36:42 »
the firmware version is ixus75_sd750-102a, please don't rush to build
It's an easy change. Test build attached.

Quote
it as I need (lots of) time to make a 3 terminal battery (with each terminal positioned precisely enough),
FWIW, I found it pretty easy to bodge a usable terminal on all my lithium battery cameras using either a real battery or the canon fake battery adapter. See https://chdk.setepontos.com/index.php?topic=10385.msg137582#msg137582 for an example.
Don't forget what the H stands for.

Re: Battery third (temp) terminal as multipurpose analogue input
« Reply #195 on: 03 / January / 2019, 13:20:35 »
Hi reyalp,
 so I loaded this, with a real battery and copper foil tape + wire + a 1k resistor acting as a controllable middle terminal, and I attached a usb cable purely so I could touch the resistor to the cable ground for my on/off pulse.
 When I grounded the end of the resistor, the AF assist light goes on and shooting starts (and sometimes completes) but then the lens retracts, the camera says 'change the battery' and it shuts down. If it actually shoots a photo, then it completes saving the photo to the sd card first.
 the battery reports 80+ % in chdk. No scripts were running. I saved the crashlog but when I opened it, the date is from October 2018 (and the camera date is correct, it knows today is 3rd Jan 2019), so it doesn't seem to be related.
 there's no urgency at all for this,
thanks,
andrew

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Offline reyalp

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Re: Battery third (temp) terminal as multipurpose analogue input
« Reply #196 on: 06 / January / 2019, 19:52:58 »
Hi reyalp,
 so I loaded this, with a real battery and copper foil tape + wire + a 1k resistor acting as a controllable middle terminal, and I attached a usb cable purely so I could touch the resistor to the cable ground for my on/off pulse.
Did you try shooting manually using the shutter button with the same rig in place?

You could also switch CHDK battery display to voltage so you can watch what it does when you connect the remote. If you do this with remote disabled, you can check if it's the electrical connection alone is enough to trigger shutdown, or if it's tied to the shooting process.

1k is pretty low, from my notes the camera would see this as about 80c, which could conceivably trigger some protection software. Something like 3k should trigger reliably without sending extreme values to the camera.
Don't forget what the H stands for.

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Offline Ant

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Re: Battery third (temp) terminal as multipurpose analogue input
« Reply #197 on: 07 / January / 2019, 13:58:36 »
Just FYI.
Playing with QEMU I discovered that Canon EOS M3 measures the voltage at the USB power input using ADC channel #2 to detect USB connection. (see 0xFC074F72)
Maybe other cameras can do that too.
« Last Edit: 07 / January / 2019, 14:19:07 by Ant »


Re: Battery third (temp) terminal as multipurpose analogue input
« Reply #198 on: 07 / January / 2019, 14:30:09 »
Hi reyalp,
 it all works now, thank you. first, testing whether the battery had enough power left to shoot at all showed that it did. The I disabled remote, and just grounding the 1k resistor made the camera shut down with the 'change battery' message.

 Using a 5k resistor instead worked fine, completely as expected,
andrew


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Offline reyalp

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Re: Battery third (temp) terminal as multipurpose analogue input
« Reply #199 on: 08 / January / 2019, 00:23:06 »
Using a 5k resistor instead worked fine, completely as expected,
Thanks for confirming. I've enabled this in the trunk 1.5 autobuilds starting at 5149
Don't forget what the H stands for.

 

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