buy a cheap ready-made remote control (no DIY, no soldering)

Paco

77

Re: buy a cheap ready-made remote control (no DIY, no soldering)

« Reply #20 on: 13 / July / 2015, 20:14:50 »

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Krist, I just bought this thing on eBay (1x AA Battery Power Supply With Flashlight USB Emergency Charger For Smart Phone) and the OFF output is 3V! GRRRRRRR! So there is no OFF. The ON voltage is 5.5V from 2 AA batteries (~3V) so there is some sort of (probably primitive) step-up circuit. No visible way to open the case without breaking it so I can't look. Needless to say it doesn't work as a remote switch. I messaged the seller. Awaiting answer. Was your OFF voltage 0V?

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waterwingz

12140

Re: buy a cheap ready-made remote control (no DIY, no soldering)

« Reply #21 on: 13 / July / 2015, 21:01:24 »

It might just need a load to discharge? Try putting a 1K resistor in parallel with their output?

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Ported : A1200 SD940 G10 Powershot N G16

Paco

77

Re: buy a cheap ready-made remote control (no DIY, no soldering)

« Reply #22 on: 13 / July / 2015, 22:02:53 »

Quote from: waterwingz on 13 / July / 2015, 21:01:24

It might just need a load to discharge? Try putting a 1K resistor in parallel with their output?

How would you do that without breaking it open and what good would it do? You'd still have the full 3V across the resistor and now it would discharge the batteries. Putting the resistor in series would effect a voltage drop but you'd still have to break the thing open. I will just request a new unit.

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waterwingz

12140

Re: buy a cheap ready-made remote control (no DIY, no soldering)

« Reply #23 on: 13 / July / 2015, 22:13:27 »

Quote from: Paco on 13 / July / 2015, 22:02:53

How would you do that without breaking it open and what good would it do?

I would carefully slice open the USB cable that goes between the camera and battery power supply, strip a little insulation from the red and black wires and insert the resistor between them (being careful not to let them short - strip them an inch apart within the cable). You would not even need to solder if you wrap the wires around the resistor ends tightly and then tape everything up.

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You'd still have the full 3V across the resistor and now it would discharge the batteries.

I'm going on the assumption that you measured the output pins from the battery power supply "open circuit"? Without a load, the output capacitor of the supply will hold a voltage for quite a while when the power switch is turned off. The parallel resistor will bleed that off quickly.

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Putting the resistor in series would effect a voltage drop

Actually, a series resistor really won't do much. The input impedence of the USB +5V pin is so high that it draws essentially no current. So there is no current flowing through a series resistor and thus no voltage drop.

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I will just request a new unit.

Don't be too surprised if the new one does the same thing.

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Ported : A1200 SD940 G10 Powershot N G16

Paco

77

Re: buy a cheap ready-made remote control (no DIY, no soldering)

« Reply #24 on: 14 / July / 2015, 18:25:12 »

Quote from: waterwingz on 13 / July / 2015, 22:13:27

I would carefully slice open the USB cable that goes between the camera and battery power supply, strip a little insulation from the red and black wires and insert the resistor between them (being careful not to let them short - strip them an inch apart within the cable). You would not even need to solder if you wrap the wires around the resistor ends tightly and then tape everything up.

You'd still have the full 3V across the resistor and now it would discharge the batteries.

I'm going on the assumption that you measured the output pins from the battery power supply "open circuit"? Without a load, the output capacitor of the supply will hold a voltage for quite a while when the power switch is turned off. The parallel resistor will bleed that off quickly.

Ouch! That sounds brutal. I'm assuming you meant 'would NOT discharge the batteries'? I'd buy the capacitor theory except that even if I short the output pins, they just go right back up to 3V with the switch in the OFF position. OFF apparently switches in some lower voltage output. The voltage remains at 3V when the LED is switched on.

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I will just request a new unit.
Don't be too surprised if the new one does the same thing.

I won't since the seller told me the 3V is normal. }8(

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waterwingz

12140

Re: buy a cheap ready-made remote control (no DIY, no soldering)

« Reply #25 on: 14 / July / 2015, 18:38:59 »

Quote from: Paco on 14 / July / 2015, 18:25:12

Ouch! That sounds brutal. I'm assuming you meant 'would NOT discharge the batteries'?

I didn't say that - I was quoting what you said there.

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I'd buy the capacitor theory except that even if I short the output pins, they just go right back up to 3V with the switch in the OFF position. OFF apparently switches in some lower voltage output. The voltage remains at 3V when the LED is switched on.

Sound like OFF just gives you the output of the batteries through whatever buck-boost regulator they have. When you put the switch in the ON position it actually enables that regulator and you get 5V. Kind of nasty but I guess what do you want for $1.78 plus 3 cents for shippping?

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Ported : A1200 SD940 G10 Powershot N G16

Paco

77

Re: buy a cheap ready-made remote control (no DIY, no soldering)

« Reply #26 on: 17 / July / 2015, 22:28:45 »

Quote from: waterwingz on 14 / July / 2015, 18:38:59

Sound like OFF just gives you the output of the batteries through whatever buck-boost regulator they have. When you put the switch in the ON position it actually enables that regulator and you get 5V. Kind of nasty but I guess what do you want for $1.78 plus 3 cents for shippping?

Yeah. OFF is probably full battery voltage. ON is through the boost circuit. And LED is also through the boost circuit since it needs more than 3V.

I was expecting this to work right out of the box like it did for FREE Spirit. All these units, no matter who sells them, must be made from the same components from the same manufacturers. What is different about my camera or version of CHDK?

The seller will send me a new unit so I can see if it is different.

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waterwingz

12140

Re: buy a cheap ready-made remote control (no DIY, no soldering)

« Reply #27 on: 17 / July / 2015, 22:42:09 »

Quote from: Paco on 17 / July / 2015, 22:28:45

I was expecting this to work right out of the box like it did for FREE Spirit. All these units, no matter who sells them, must be made from the same components from the same manufacturers. What is different about my camera or version of CHDK?

I'm pretty much sure it has nothing to do with your version of CHDK. However, it might have something to do with your camera or (more likely) with the actual batteries you are using.

Typically, a set of AA cells does actually not deliver a full 3V unless they are brand new alkalies. Rechargable batteries deliver a little bit lower voltage as do older batteries.

The thing to realize here is that typically 3V is not enough to trigger the 5V input level detect on most Canon cameras. But on some I believe it will. So the question becomes one of threshold tolerances. If the voltage from two new AA cells is giving you enough voltage that the camera thinks there is power being applied to the USB connector +5V pin then try a set of older rechargable NiCad batteries. You won't get much more than 1.2 volts from each of them and that should be enough so that CHDK thinks the remote is "off".

Heck, you might be able to run that unit on just one 1.5V battery by jumping out the slot where the other battery was supposed to be installed. Worth a try?

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Ported : A1200 SD940 G10 Powershot N G16

Paco

77

Re: buy a cheap ready-made remote control (no DIY, no soldering)

« Reply #28 on: 17 / July / 2015, 22:50:19 »

Quote from: waterwingz on 17 / July / 2015, 22:42:09

Typically, a set of AA cells does actually not deliver a full 3V unless they are brand new alkalies. Rechargable batteries deliver a little bit lower voltage as do older batteries.

You're right. The batteries are alkaline.

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The thing to realize here is that typically 3V is not enough to trigger the 5V input level detect on most Canon cameras. But on some I believe it will. So the question becomes one of threshold tolerances. If the voltage from two new AA cells is giving you enough voltage that the camera thinks there is power being applied to the USB connector +5V pin then try a set of older rechargable NiCad batteries. You won't get much more than 1.2 volts from each of them and that should be enough so that CHDK thinks the remote is "off".

Heck, you might be able to run that unit on just one 1.5V battery by jumping out the slot where the other battery was supposed to be installed. Worth a try?

What is the typical threshold for LOW? Both these ideas are worth a try.

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waterwingz

12140

Re: buy a cheap ready-made remote control (no DIY, no soldering)

« Reply #29 on: 17 / July / 2015, 23:23:52 »

Quote from: Paco on 17 / July / 2015, 22:50:19

What is the typical threshold for LOW? Both these ideas are worth a try.

I don't think this has ever been discussed. The more common problem has been getting enough voltage for a HIGH using coin cells etc. You could experiment with a DVM and a 1K potentiometer (as the +5V input is essentially high impedance). Connect the two end of the pot to the device and the wiper & negative terminal to the camera.

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Ported : A1200 SD940 G10 Powershot N G16