Mobius being fickle with certain USB power supplies- using power on record

murcod

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Dash Cam
Mobius, A119v2, A119v3
I guess it's a regular topic on this forum- the idiosyncrasies of the Mobius and vehicle power supply fluctuations eg. when starting the engine.

I'm installing my old Mobius into a new vehicle and am now trying to get it to record using a power source that loses +12V for a split second on engine start. Starting the engine is enough to shut down the Mobius and then it will sit there with the charging LED lit doing nothing. My digital multimeter just picks up the drop out (I know they're slow to register voltage fluctuations.)

I had a brilliant (and cheap) idea to use a delay timer in the supply line- to give the Mobius a 10 second delay before power reapplication when the engine is started. Plenty of time for it to sort itself out. It was all fine in theory -and the timer works - the major issue is the timer doesn't pick up on the voltage fluctuations that causes the Mobius to shut down. So it doesn't reset itself and do the 10 second turn on delay! :(

So has anyone got any other ideas for reliable operation on a problem power supply circuit? Are there any super stable 12V USB power converters with lots of inbuilt filtering?

(I can't help but think surely some sort of internal software/ firmware check on the power status must be possible- to trigger a restart?)
 
don't do a startup delay (I still don't get why some people think this approach is better), do a shutdown delay timer instead, once power is received it will hold the power on for a preset time, it will remain on for that amount of time at key off but that's not really an issue anyway and it will handle power cut during cranking etc, check this thread for details on how to set up a shutdown delay timer https://dashcamtalk.com/forum/threa...lay-shutdown-circuit.12845/page-2#post-167750
 
I have 2 mobius straight from car battery and i never had any problems, but can somebody explain why car audio capacitor would NOT work in this situation, somehow i think it should give enough power to overcome that gap?
Something like this i mean
https://www.ebay.com/itm/351639308531
 
don't do a startup delay (I still don't get why some people think this approach is better),

Because, since installing a 10s delay into the power supply, I haven't had a single operating problem with my cameras.
Previously, I was driving along, completely unaware that the camera wasn't recording since all the usual lights were showing, and this was on cameras with a screen and internal battery (G1W, DR32 etc).
Even with my modern diesel engine, I cannot simply throw the key & the engine fires, I HAVE to wait for the glowplug light to go out - even on a hot day with a hot engine, it seems to be a foible of my car.
Whilst I wait for the glowplug light, the cam has power. Cranking the engine shuts power to all accessories (to allow maximum power to the starter). The cam thinks this loss of power means it's time to shutdown.
As soon as the engine fires, the key is returned to the normal running position & power is returned - meanwhile, the cam is still in the process of shutting down.
A delay timer means that nothing is getting through to the cam until the timer has had a constant supply for (10seconds in my case).
And this is why I, personally, like this approach.

I had a brilliant (and cheap) idea to use a delay timer in the supply line- to give the Mobius a 10 second delay before power reapplication when the engine is started. Plenty of time for it to sort itself out. It was all fine in theory -and the timer works - the major issue is the timer doesn't pick up on the voltage fluctuations that causes the Mobius to shut down. So it doesn't reset itself and do the 10 second turn on delay! :(

Have you tried setting the delay for longer? My delay timer lets nothing through until it has had power for the set time & I find that 10s is more than enough time for my car's startup regime, the momentary fluctuation you mention shouldn't impact on the cam as long as it occurs within the delay.
 
the delay timer is a one size fits some solution, if it works for you that's all well and good, doesn't work for all unfortunately
 
don't do a startup delay (I still don't get why some people think this approach is better), do a shutdown delay timer instead, once power is received it will hold the power on for a preset time, it will remain on for that amount of time at key off but that's not really an issue anyway and it will handle power cut during cranking etc, check this thread for details on how to set up a shutdown delay timer https://dashcamtalk.com/forum/threa...lay-shutdown-circuit.12845/page-2#post-167750

I went with the start up delay because it's the simplest approach and should work. It also should work without requiring an additional permanent 12VDC connection (plus possible parasitic drain.) It's a new vehicle so the less wiring I interfere with the better (this delay timer is set up to work off the same source that powers the Mobius.) PS: See the bottom of the post...

I have 2 mobius straight from car battery and i never had any problems, but can somebody explain why car audio capacitor would NOT work in this situation, somehow i think it should give enough power to overcome that gap?
Something like this i mean
https://www.ebay.com/itm/351639308531

Yes ,that should work. Size is a problem and it would also present a short circuit when initially connected to 12VDC - some sort of resistor to limit the charge current would work. Size was the biggest negative for me, I was actually experimenting with up to a 5600uF capacitor today and an isolation diode to prevent it discharging back into the vehicle's electrics. That wasn't enough grunt to fix it.

Because, since installing a 10s delay into the power supply, I haven't had a single operating problem with my cameras.
Previously, I was driving along, completely unaware that the camera wasn't recording since all the usual lights were showing, and this was on cameras with a screen and internal battery (G1W, DR32 etc).
Even with my modern diesel engine, I cannot simply throw the key & the engine fires, I HAVE to wait for the glowplug light to go out - even on a hot day with a hot engine, it seems to be a foible of my car.
Whilst I wait for the glowplug light, the cam has power. Cranking the engine shuts power to all accessories (to allow maximum power to the starter). The cam thinks this loss of power means it's time to shutdown.
As soon as the engine fires, the key is returned to the normal running position & power is returned - meanwhile, the cam is still in the process of shutting down.
A delay timer means that nothing is getting through to the cam until the timer has had a constant supply for (10seconds in my case).
And this is why I, personally, like this approach.

Have you tried setting the delay for longer? My delay timer lets nothing through until it has had power for the set time & I find that 10s is more than enough time for my car's startup regime, the momentary fluctuation you mention shouldn't impact on the cam as long as it occurs within the delay.

I totally agree. I've got the delay maxxed out, it's around 11 seconds (measured counting to myself...) The power source I'm using is the light circuit. It comes alive as soon as the vehicle is unlocked and power continues to be supplied for around 15 minutes after shut-down.

*** What I did just discover is my new fancy 12VDC to 5V USB power supply appears to be the cause. I'd been using using a gutted cigarette socket charger (bought with my Mobius from Eletoponline365) hard wired in to my previous vehicle, it wasn't pretty, but it worked. I decided to buy a decent charger this time and do it properly- rated at 2 Amps and complete with a 3m right angle min USB plug
I just tried out the old charger and starting the car doesn't cause the Mobius to shut down- it keeps recording!


I'll have to investigate further tomorrow (and test it again to be sure), but the old ugly solution looks to be best. I wasted the whole day tearing my hair out trying to work this one out. :mad:
 
What I did just discover is my new fancy 12VDC to 5V USB power supply appears to be the cause.
Perhaps you could use the thread tools to alter the thread title to something like "Mobius shafted by crappy Hardwiring Kit".

There should be a prominent notice somewhere on this site warning of the dangers of hardwiring kits. How many DashCams must die before something is done. Oh the humanity ... ;)
 
There should be a prominent notice somewhere on this site warning of the dangers of hardwiring kits. How many DashCams must die before something is done. Oh the humanity ... ;)

there are plenty of these hardware kits that including shipping, selling fees, profit to the seller etc are selling for less than half of what we pay for ours, you only get what you pay for o_O
 
Perhaps you could use the thread tools to alter the thread title to something like "Mobius shafted by crappy Hardwiring Kit".

There should be a prominent notice somewhere on this site warning of the dangers of hardwiring kits. How many DashCams must die before something is done. Oh the humanity ... ;)

That's being a bit melodramatic! My Mobius hasn't had the magic smoke released.... PS: Going by my findings (so far, I need to check again tomorrow) the even cheaper power supply is better! I've also been using that supply type (three of them) for a couple of years on three Mobius.

I do agree a what works/ doesn't work (with the Mobius) would be a handy thread. Currently it's all little bits of info spread everywhere. I've got a USB power/ current tester but haven't got the right adapters to test the new dodgy supply. I did test my butchered cigaretter lighter supply and it was around 5.1 to 5.2 V unloaded/ loaded with the Mobius on the end of a 3m extension.

there are plenty of these hardware kits that including shipping, selling fees, profit to the seller etc are selling for less than half of what we pay for ours, you only get what you pay for o_O

Sometimes that's the case (I'm not doubting your products) but often there are huge mark ups. Living in Australia I'm sure you've seen that a lot too.
 
The power source I'm using is the light circuit. It comes alive as soon as the vehicle is unlocked and power continues to be supplied for around 15 minutes after shut-down.
That explains why the delay isn't long enough. I have mine tapped into the cigar lighter circuit so it only gets power when I turn the key.

What I have noticed, though, my car seems to respond to any number of keyfobs operating within range. A mechanic unlocking a car in the next unit - my LEDs come on - not fully, but they all still light up.
 
That explains why the delay isn't long enough. I have mine tapped into the cigar lighter circuit so it only gets power when I turn the key.

What I have noticed, though, my car seems to respond to any number of keyfobs operating within range. A mechanic unlocking a car in the next unit - my LEDs come on - not fully, but they all still light up.

Sorry, you've lost me with the bit about the delay not being long enough?

I've got the proximity key fob entry with touch sensitive handles - it's a Ford. Close the door and touch the outside of the handle and the doors lock, touch the inside of the handle (ie. grab it like you would to open the door) and it unlocks/ turns the lights on. After turning the ignition off, the lights come on and that circuit stays alive for around 15 minutes (roughly, I haven't timed it.) The keyfob also has the normal lock/ unlock etc.

Connecting to that circuit gives me recording from the doors being unlocked, the whole trip, plus to 15 minutes of being parked. I've also tapped into that circuit using an unused plug- so no splicing into the loom was required.

I'll triple check it all works with the old power supply and then reroute the cables up to the mirror again.:(
 
Okay, all fixed and working as desired.

Lessons learned:
1. The cheap modified cigarette lighter socket charger doesn't appreciate being connect reverse polarity :( . The main regular chip pops it's innards out with the distinct smell of smoke.
2. Luckily I had a plan C . This other 12V to 5V USB supply/charger works very well (I did retest the other - it's still a dismal failure at isolating supply spikes.)

I checked the output of the "Plan C" charger and it's 5.10 to 5.20V before the 3m extension. (Measured using a Mobius with a super cap conversion.) So this one is worth a look:
I also did wire in the delay timer - set to around 5 seconds. It's a precaution as I've had instances in my other car where the Mobius sometimes fails to start recording- I'll be fitting a delay timer in it.
 
Sorry, you've lost me with the bit about the delay not being long enough?

I've got the proximity key fob entry with touch sensitive handles - it's a Ford. Close the door and touch the outside of the handle and the doors lock, touch the inside of the handle (ie. grab it like you would to open the door) and it unlocks/ turns the lights on. After turning the ignition off, the lights come on and that circuit stays alive for around 15 minutes (roughly, I haven't timed it.) The keyfob also has the normal lock/ unlock etc.

Connecting to that circuit gives me recording from the doors being unlocked, the whole trip, plus to 15 minutes of being parked. I've also tapped into that circuit using an unused plug- so no splicing into the loom was required.

I'll triple check it all works with the old power supply and then reroute the cables up to the mirror again:(.
My lighting circuit activates the second I touch my key fob to unlock the doors, even with a delay timer on this, there would be times (on a 10s delay) when the cam would start recording before I interrupt power to crank the engine, so I'd want a longer delay, to be on the safe side.
However, there are times when I could be halfway down the road before the recording starts - Even with the delay on the cig lighter circuit, there ARE times when the glowplug light goes out quickly & I can set off & I'm halfway down the road...
But I accept this delay because it means that my cam isn't getting any power at all until the engine is safely running. I would rather this than the unsurity of not knowing if the cam is recording.
Even with my older cams (DR32, DOD, G1W etc) which had screens, it was never easy to tell since the recording lights always flashed as they should.
 
With the new power supply I've overcome the ignition cranking causing the Mobius to fail. I've left the timer in "just in case" I somehow managed to jag a situtaion where the lighting circuit has just cut out and I unlock the car before the Mobius has completed it's shut down.

My other car it's running off the accessories circuit with a proximity fob and push button ignition. It never cuts out on me as I normally go from power off (all circuits) to engine running. However, the last two times I've had it serviced they've somehow managed to drive it without the Mobius running. My guess is they've had it in "accessories" or "ignition on" and then started the engine? A five odd second delay should fix that happening.
 
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