I think it is a digital signal on pin 4, as in high or low, and probably at TTL voltage levels.

Note: The words "I think" mean that I am not certain!
You are correct, I’m not certain either ;)
 
with the price of the kit being under $20, I am sure its analog. I am almost positive it just turns one of the signal wires on or off that goes to the cam.... I will find out.....
It uses ID pin, i've checked my 3wire kit now (i think in the EGS's image the pins order is swapped). And i'm about to wire that thing (finally!) to oscilloscope to check other stuff. :)



EDIT: Nope, EGS’s image is correct, they looked like male and female to me at first glance.
 
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what voltage level on pin4 - 3.3v or 5v ?
when acc on - pin4 is high or low?

It uses ID pin, i've checked my 3wire kit now (i think in the EGS's image the pins order is swapped). And i'm about to wire that thing (finally!) to oscilloscope to check other stuff. :)



EDIT: Nope, EGS’s image is correct, they looked like male and female to me at first glance.
 
Just registered to give the answer:

The hardwire kit does not work for me because I want to use a powerbank for parking mode so that I do not drain the car battery and can record for a long time.
Btw: my viofo A119 V3 consumes 273 mAh (per hour) in driving mode and with h265 codec.

Prerequisite: you need to enable parking mode in the menu (e.g. auto event detection).

If GND is connected to USB pin 4 (ID) the cam will enter parking mode.
If VCC -> 5k Ohm resistor -> USB pin 4 (ID): the cam will enter driving mode/exit parking mode.

For this to work the cam must be first powered up in driving mode - this triggers the automatic switch by sensing the ID pin.

The switchover is instantaneous, not the motion detection based switching which also does not work.

I used three relays to perform the switchover from car battery while driving and powerbank when parked. If someone is interested I could provide a schematic.
 
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Here you go:
circuit.png
Link to schematic for editing

I had to use the capacitor because my powerbank is hidden under the passenger seat and the cables are not the thickest - without it the camera would power down during switchover from car to powerbank power due to a short drop in voltage.
This is a problem because when the camera comes up again with powerbank power it does not switch into parking mode, as mentioned it seems that it first needs to "see" a non GND signal on the ID pin to "understand" that it's connected to a hardwire-kit/this circuit.

I used the LM2596 DC-DC buck converter:
lm2596.jpg
USB pinout:
miniusb_pinout.jpg

Btw: Car and Powerbank share a common ground.
 
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Right, now I'm nowhere near as cluey as the guy above ;) but have a slightly different dilema regarding the HK3 3 wire hardwire kit.

I recently purchased 2 x A119V3 cams with hardwire kits to use front & rear for my daily which is a 2017 Toyota Aurion. I wanted to be able to control when the cams go into park mode rather than them always switching to park mode after you switch engine/ignition off.

I thought about wiring a switch inline with the ‘always on’ battery wire to the hardwire kit but have found that doesn’t work as the cam needs that wire always on for it to work - of course I didn’t know this. I’m now finding that despite leaving the switch on permanently, the hardwire kit is shutting down soon after I switch the ignition off, perhaps 30seconds or so, yet the car is still powering as usual. I know the Viofo HK3 hardwire kit is shutting down as I can see the internal LED’s switch off just before the cam switches off.

Is there a way of making this hardwire kit & cams work for me? Have I accidentally damaged the hardwire kits internal board ?

I’m considering getting a Vico Power-Plus (have in 2nd car) which will work but the cam doesn’t actually go into park mode but rather record non-stop, although I only tested it for about a minute. The BlackVue in my other car switches over to park mode after about 5 minutes - I guess they call it smart.

Any advice appreciated.

Cheers
 
I’m now finding that despite leaving the switch on permanently, the hardwire kit is shutting down soon after I switch the ignition off,
What cutoff voltage is it set to, and what is the battery voltage when it shuts down?

Is there a way of making this hardwire kit & cams work for me?
If you wire it up normally, then you can choose to turn the camera off when parked by long pressing the power/menu button, it should automatically restart when you restart the engine.
 
Howdy Nigel,

Cutoff was initially set to 12.4 but then lowered it to min to see if any reaction. Car has 16.8V (CTek charge other day) although can't recall testing direct out of hardwire kit which should be 0V.

I'm aware of shutting cams down manually but it's a real pain esp the rear cam & no good if I forget either.

ps: have also tried direct to Batt+ with same result. I have seen it run once or twice but only tested for 2-3 minutes
 
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If the red LED inside the kit is going out about 90 seconds after the car is shut off, then most likely the kit is sensing voltage below the cutoff. Have you measured the voltage at the fuse after the kit has shut down?
 
Right you are sir ^^^ I have found the culprit !

Viofo HK3 kit working as it should. Problem solved - my mistake !

Also can anyone tell me if there any advantages to using park mode in these things ? The way I see it is that they're always on anyhow (ie: always using power) and will record @ either low bit rate or run via Auto Detection which is what I preferred. Would it be any different if I just ran the cams full time under normal power, ie: an always on hardwire kit? I understand I will be using more of my SDXC card as it's recording non-stop - that's fine as I have a 256GB card & I don't expect to ever run out of space in the week that I use it before copying & reformatting it on my Mac.

Also anyone here object to using the fuse tap the other way round, ie: not as per attached images? It would appear to still work & protect said fuses, I'm using the car's "S/ROOF 10A" fuse which on my Toyota isn't occupied for anything. Win win I think.

Let me know your thoughts,

Cheers ;)
 

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I can only presume because it's a relatively new car @ 3 yrs & that I did a full re-charge of the car battery with my CTek charger the other day & it hasn't been used or started since then. It is pretty high though either @ battery or thru fuse.
 
Despite the vehicle always at 16.7V min & during testing earlier today measuring 17.5-18.25V,
I did a full re-charge of the car battery with my CTek charger the other day

1. A CTek battery charger will not charge a battery above 14.6V.
2. A lead acid battery at 17V + will vent hydrogen and either explode, or just die when it's cells dry up.

I assume that you are not measuring the voltage correctly, and that the HK3 is shutting down on low voltage, exactly as it is supposed to do.

...
 
Could be the meter is set to AC instead of DC; an easy mistake to make on a lot of meters with too-small markings like mine.

Phil
 
Hi everyone,

I need to apologise to everyone including Viofo for bad mouthing their product without qualifying my equipment.

I have made an embarrassing discovery which I thought was not possible - the 9V battery in my multi-meter was half dead :/ As a result it was not reading correctly & to the tune of 4.5V more - I can't believe it ! I verified my meters accuracy with that of my mate mechanic & it's now within 0.1V which is OKish. My Vico Power Plus measuring same figure.

So I'm now getting 12.19V at the fusebox, 12.2V at the battery (should be 12.6V) coupled with the extra initial load of the cam startup explains why the HK3 kit was shutting down @ 12.2 & 12.4V. Damn. Now need to verify car battery is OK longterm, bought this car a few months ago & reckon original owners may have killed it as it hardly got driven.

Therefore Viofo HK3 kit working as it should. But I'm not a fan of the way these cams work always on after ignition off until low battery &/or full SDXC card so I'll invest in another Vico PowerPlus for this daily driver which will allow me to switch when I want park mode on.

Sorry to have bothered you all, I'm just a goof sometimes especially in these current times (get it) as I was recently stood down & have lost all motivation. Have pitty on me yada yada . . .

Cheers ;)

Battery Aziz . . . . .
 
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Well it’s good that you’ve managed to actually find out what the issue might be [emoji3]
 
Here you go:
View attachment 51241
Link to schematic for editing

I had to use the capacitor because my powerbank is hidden under the passenger seat and the cables are not the thickest - without it the camera would power down during switchover from car to powerbank power due to a short drop in voltage.
This is a problem because when the camera comes up again with powerbank power it does not switch into parking mode, as mentioned it seems that it first needs to "see" a non GND signal on the ID pin to "understand" that it's connected to a hardwire-kit/this circuit.

I used the LM2596 DC-DC buck converter:
View attachment 51238
USB pinout:
View attachment 51240

Btw: Car and Powerbank share a common ground.

Can this DC-converter be used in winter and summer in a car? Could the too low or high temperature cause any problem? I ask it because in parking mode the heating/air conditioning is off and the camera should record further and i don't want to see the car in flames :)
 
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