HK3-H hardware kit arrives! (Viofo is not going to be happy about it)

[bobcat]

The logic board is the same for both, you'd keep the cable and solder in the connections. Overall though there is not much demand for such highly specialized boards (which is understandable), while the minimum order for me is something like 200+ $. I'll still be ordering and testing second revision once the parts are back in stock. Will post an update then

 

[Daijoubu]

Very cool project, I have a 70mai dashcam and after a bit of reverse engineering, I simply modified the voltage divider to increase the cut off voltage, if the Viofo kit also uses a MCU for this then it will probably implemented in a similar fashion.

 

[bobcat]

Update #6:

Hello my fellow dashcam enthusiasts!
Long time no see post! I've finally found some time to finalize the revised version of my HK-kit and order it with my Chinese manufacturer. Below are the first photos of the assembled boards:



As you may recall, my intent was to combine everything I wanted from the HK kit into one board (LoRa, accelerometer, multi-point temps readings, power consumption, low power mode controls, etc...), as well as to test new DC regulator and take to the limits manufacturing capabilities of my Chinese supplier. I've only ordered 2 boards as my supplier was low on stock on one of the key parts.

Well, I got some results - none of the two boards worked from the start!

However, I've eventually managed one of the boards to function after some root-cause analysis and was able to test the capabilities of the HK kit, albeit not the way I intended the whole thing to go.

The good news is that the "power" portion of the circuit exceeded all of my expectations! The DC-DC converter is extremely efficient with virtually no noise! I got over 95% efficiency and what is even better is that the circuit barely heats up! In fact I was able to feel some heat only when I loaded 1.6 Amps on the output, and after about an hour the regulator temps did not exceed 45C! Running only the A129Pro as my test load, temps stayed under 35C which is about 7C above ambient.

Now to the bad news! The reason why the boards did not work out of the box was because... Well, I wanted to test manufacturing capabilities of my Chinese supplier - I've found them out! Some of the parts that I've used were extremely small and right on the edge of listed capabilities. I had a tiny linear voltage regulator to power all the 3.3v stuff which turns out has failed at the connection end. That part is smaller than your classical 0603 size resistor, yet has 5 pads underneath. I believe the output pad of that part did not get properly connected to the board, so I never got 3.3v out. And there is no way of fixing it, so I had to improvise and find a replacement for that part (so that I could test things out). And here is the photos of my "fix", lol:



I've basically soldered a 3.3v regulator right on top so that I can power all the 3.3v stuff and get to testing!

Overall I've spent over $200 on these 2 boards, but I don't regret it, as I've gained knowledge which is valuable for my other projects.

What's next!? I'm now into working on R3, where I part ways from the very tiny parts so that I no longer have this issue again and would also include an automotive grade Molex connector on the camera end. This will help me avoid soldering stuff inside of my cars and instead use a proper connector! Below is the first render of the new revision (for those of you who are still reading my post, lol):




I could have kept quiet about some of these failures, but I believe knowledge is power and thought to share these experiences, which one day may be helpful to others

As always, if you have any recommendations or suggestions on functionality, my attention is all yours!
Cheers!

 

[el-guapin]

This is gonna be GOOD!!

 

[Daijoubu]

I would do temperatire compensated low voltage cutoff hehe, I went with a different approach, I'm gonna slap the largest solar panel I could fit on my dash, 50W and use an CN3767 pseudo MPPT charge controller and have infinite parking mode unless it's cloudy many days in a row lol

 

[bobcat]

I would do temperatire compensated low voltage cutoff hehe, I went with a different approach, I'm gonna slap the largest solar panel I could fit on my dash, 50W and use an CN3767 pseudo MPPT charge controller and have infinite parking mode unless it's cloudy many days in a row lol

I see what you're saying. My approach is a bit different. My logic would be: run parking mode for 4-5 hours, then switch to "passive" park mode where camera does not get any power at all, but the device is live for weeks monitoring motion but without draining battery, and upon motion/ collision detection turn on camera as if I'm driving. I'd lose about 13 seconds between "motion/ collision" detection but willing to live with it as long as I get weeks from HK kit without extra necessities.

Although kinda sucks that viofo cameras take 13-15 seconds to boot. If they booted at 5 seconds or less, it would have been ideal.

 

[el-guapin]

Any update /progress on this?

 

[bobcat]

Any update /progress on this?

Been busy with other projects so I've somewhat dumped this one. Have updated design ready, but never really ordered manufacturing of the pcbs.

 

[wasyoingonce2]

Roll your own always costs more in dev but you end up with something that works. Well most of the time. Half diy end up dying due to costs and by around the 3rd or 4th derivative PCB it’s really costing and time consuming.

This I know. But kudos try to keep it rolling I’d buy it. If just to play. I also like the connectors used as just makes it easier.

Cheers

Bren

 

[bobcat]

Roll your own always costs more in dev but you end up with something that works. Well most of the time. Half diy end up dying due to costs and by around the 3rd or 4th derivative PCB it’s really costing and time consuming.

This I know. But kudos try to keep it rolling I’d buy it. If just to play. I also like the connectors used as just makes it easier.

Cheers

Bren

Hi there Bren,

Pretty much what you have described in your post! I've already spent over $500 on existing iterations and going with high quality automotive parts adds up to the costs quickly! For now I've put the project on hold since latest official HK kit is not that bad and very few people are interested in all the additional bells and whistles. I still chase the idea of extended parking mode based on motion detection, so maybe will get back to the project one day. I'd also need a custom enclosure for the latest PCB, but my bambu lab x1c is on the way, so this no longer seems to be a problem and maybe one day I'll resume the works

Best,
Anvar

 

[JardaB]

Please make something that we can go below 11.8v. Sometimes my battery pack is 50% + and my dashcam shuts off in parking mode because the battery pack is a little cold and drops below 11.8v.

You don't like your car accumulator ?

Below are the 12V terminal voltages of a disconnected AGM battery at empty (no appliance must be connected to the terminals) at 20 deg. Celsius and approximate state of charge:
12,8V = 100%
12.5V to 12.6V = 75%
12.2V to 12.3V = 50%
12.0V to 12.1V = 25%
11.8V = discharged

What you are asking for is a temperature compensated voltage value to stop the discharge . If we can get the AGM battery to a deep discharge (some manufacturers refer to the voltage drop of an AGM battery as below 11.5V - Yuasa, for example), we may not be able to address this condition !!!.

Deep discharge - always shortens battery life. It's such a discharge where the voltage drops to 10.5V or even below. So discharged the battery must be recharged immediately or risk massive sulphation. Discharging to 10.5V or below is considered deep discharge. Deep discharging damages the battery - shortens its life, leads to rapid sulphation, increased internal resistance and electrolyte depletion, leading to battery failure.

 

[Dadi_T]

You don't like your car accumulator ?

Below are the 12V terminal voltages of a disconnected AGM battery at empty (no appliance must be connected to the terminals) at 20 deg. Celsius and approximate state of charge:
12,8V = 100%
12.5V to 12.6V = 75%
12.2V to 12.3V = 50%
12.0V to 12.1V = 25%
11.8V = discharged

What you are asking for is a temperature compensated voltage value to stop the discharge . If we can get the AGM battery to a deep discharge (some manufacturers refer to the voltage drop of an AGM battery as below 11.5V - Yuasa, for example), we may not be able to address this condition !!!.

Deep discharge - always shortens battery life. It's such a discharge where the voltage drops to 10.5V or even below. So discharged the battery must be recharged immediately or risk massive sulphation. Discharging to 10.5V or below is considered deep discharge. Deep discharging damages the battery - shortens its life, leads to rapid sulphation, increased internal resistance and electrolyte depletion, leading to battery failure.

I think it's not talking about the car battery.

 

[JardaB]

You're right, I linked to the last posts instead of the first original. If I look at it it says HK3 replacement i.e. intended for car batteries.

On a quick preview I didn't find any mention of using it for a special additional battery designed for parking mode.
If that was the intent it would be wrong again, so the battery shutdown was designed by the manufacturer

After all, pointing out the dangers that can be created by amateurs setting the shutdown voltage to low values doesn't hurt.

In a post Jan 30, 2023 Panzer Platform writes quote "l Low Voltage Cut Off values of 11.6V, 11.4V, or better " ...... That's car battery murder

 

[LateralNW]

You're right, I linked to the last posts instead of the first original. If I look at it it says HK3 replacement i.e. intended for car batteries.

On a quick preview I didn't find any mention of using it for a special additional battery designed for parking mode.
If that was the intent it would be wrong again, so the battery shutdown was designed by the manufacturer

After all, pointing out the dangers that can be created by amateurs setting the shutdown voltage to low values doesn't hurt.

In a post Jan 30, 2023 Panzer Platform writes quote "l Low Voltage Cut Off values of 11.6V, 11.4V, or better " ...... That's car battery murder

The information you supplied is very informative and will be useful for forum readers who are using lead acid batteries.

However in this case this person is referring to a seperate battery system.
When they state "Battery Pack" it is different from the car standard battery.
Most likely a LiFePO4 type of backup battery of some sort.

A common problem I see on this forum is users who want to get the maximum energy out of their battery packs that use LiFePO4 as they are able to supply power to a lower level based on the indicators their system uses.

Sometimes my battery pack

 

[JardaB]

It amazes me that the disconnection of such a battery after reaching low voltage is not controlled directly by this battery.
I believe that tampering with the supplied HK4 kit to achieve a lower final voltage and longer run time is highly amateurish (I don't want to use a more expressive term ) and damaging to the condition and safety of an expensive battery (PowerCell 8 et cetera) and especially shortening its life.

Exceeding the limiting voltage of a discharging battery seriously damages it - regardless of its internal design

Well ... let the boys play, the hobby is a hobby

 

[bobcat]

It amazes me that the disconnection of such a battery after reaching low voltage is not controlled directly by this battery.
I believe that tampering with the supplied HK4 kit to achieve a lower final voltage and longer run time is highly amateurish (I don't want to use a more expressive term ) and damaging to the condition and safety of an expensive battery (PowerCell 8 et cetera) and especially shortening its life.

Exceeding the limiting voltage of a discharging battery seriously damages it - regardless of its internal design

Well ... let the boys play, the hobby is a hobby

Maybe I'm misunderstanding something, but are you referring to me and the work I've done on this project?

 

[JardaB]

I really don't know what you feel personally offended by. I didn't call anyone names, I didn't use vulgar or similar language. He just lightened the discussion with an attempt at a joke. If you were personally offended by the joke - I apologize. If you wish, I'll delete the attempted joke Deleting this section will not change the substance of my comment.

You can do anything freely regardless of the opinions of others. Just because we have a different opinion on a matter doesn't mean we have to frown on ourselves.

If you found any inaccuracy or false information - please tell me. I'm not God and I don't know everything exactly

 

[bobcat]

I really don't know what you feel personally offended by. I didn't call anyone names, I didn't use vulgar or similar language. He just lightened the discussion with an attempt at a joke. If you were personally offended by the joke - I apologize. If you wish, I'll delete the attempted joke Deleting this section will not change the substance of my comment.

You can do anything freely regardless of the opinions of others. Just because we have a different opinion on a matter doesn't mean we have to frown on ourselves.

If you found any inaccuracy or false information - please tell me. I'm not God and I don't know everything exactly

I just did not understand who that comment was referencing to. Not offended in any way lol. I'm in fact of the same opinion of not pushing the voltages on the batteries.

As for my project, all the power circuit of it is a lot more Automotive grade, has more protection, and higher quality/automotive grade parts then the original kit. I've done enough research and testing to be confident to say that, so by no means it's tampering with the original kit. Although the whole thing on this project started as a hobby few years back I run low voltage electronics design company, so can't really agree my work in here is playing with toys, but an attempt to improve the design and get it a bit more automotive grade. For example the inductor used in the original kit alone would not pass any emc/design rules and guidelines for auto applications, but we as users generally don't see any side effects as typically this HK kit sits far enough from the sensitive electronics of modern cars.

 

[JardaB]

I understand your professional and qualitative perspective. I have so far registered only one substantive comment on the original product - that is the consistency or inconsistency (accuracy) of the actual shutdown with its settings.