Comma AI self driver assistant

[EVO]

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[itsjmod]

Reverting my poor harness back to the OBD-C original location while I wait for my new harness from Comma since I have the coupler now

I’m getting better at soldering and this wiring stuff though which is good.

Question - is the coupler supposed to work on just normal power or does it need the expected voltage from the truck? Neither the comma or anything else turns on or charges using it in the middle of any 2 USB-Cs. I’ve tried plenty of verified 3.1 Gen 2s of different sizes and using the stock comma angled short cord on the last mile. No device or the comma gets power

Want to rule out a possible faulty coupler as I’m doing this wiring cause I’ll order a new one if this isn’t expected, but I reckon Ill find out in the next few days when I try to connect it all up anyway haha

 

[itsjmod]

Oh and I’m soldering the wires and just super gluing the screws on

 

[B177y]

Reverting my poor harness back to the OBD-C original location while I wait for my new harness from Comma since I have the coupler now

I’m getting better at soldering and this wiring stuff though which is good.

Question - is the coupler supposed to work on just normal power or does it need the expected voltage from the truck? Neither the comma or anything else turns on or charges using it in the middle of any 2 USB-Cs. I’ve tried plenty of verified 3.1 Gen 2s of different sizes and using the stock comma angled short cord on the last mile. No device or the comma gets power

Want to rule out a possible faulty coupler as I’m doing this wiring cause I’ll order a new one if this isn’t expected, but I reckon Ill find out in the next few days when I try to connect it all up anyway haha

If I am following correctly, you're asking if the Comma will power on if you add the coupler to a USB cord that is plugged in to a USB power source like a phone charger, not the truck?

 

[itsjmod]

If I am following correctly, you're asking if the Comma will power on if you add the coupler to a USB cord that is plugged in to a USB power source like a phone charger, not the truck?

Correct. Like using it in my house. I thought it should work so I was trying to test but no dice. I’ll admit I’m not too versed on resistors. But yes -

MacBook brick → any USB-C → coupler → Comma stock short cord → Comma = no power

brick → any USB-C → coupler → Comma stock short cord → iPhone = no power

brick → any USB-C → Comma = power. Etc etc

I tried other bricks of various power output too

 

[chriserx]

Correct. Like using it in my house. I thought it should work so I was trying to test but no dice. I’ll admit I’m not too versed on resistors. But yes -

MacBook brick → any USB-C → coupler → Comma stock short cord → Comma = no power

brick → any USB-C → coupler → Comma stock short cord → iPhone = no power

brick → any USB-C → Comma = power. Etc etc

I tried other bricks of various power output too

Afaik it needs to be a 'dumb' power supply like what a raspberry pi 4 had to use since iirc it doesn't use the actual USB spec.
Note: I've never actually tried this, and is an educated guess.

Edit: You only need the resistor/coupler for communication with the truck. You won't need it in the house.

Edit 2: The 'dumb' power supply will likely also need to supply 12v on the line and not 5v.

 

[B177y]

Correct. Like using it in my house. I thought it should work so I was trying to test but no dice. I’ll admit I’m not too versed on resistors. But yes -

MacBook brick → any USB-C → coupler → Comma stock short cord → Comma = no power

brick → any USB-C → coupler → Comma stock short cord → iPhone = no power

brick → any USB-C → Comma = power. Etc etc

I tried other bricks of various power output too

Agree with everything @chriserx said except for "Edit 2". You can use a 5 volt USB when powering the Comma outside of a vehicle, you just have to accept the low voltage warning on the Comma. I have found that the Comma works best when connected to my powered USB hub on my desktop, but YMMV. Some USB power sources just won't work or will allow boot up but then the Comma shuts down.

When in the Lightning, you need the coupler with the resistor to prevent "CAN reflections" which cause the startup errors (I have no idea what this is, it's just what I've been told). The coupler has to be in the correct orientation as marked on the coupler itself. It can be installed anywhere along the USB lines.

The OBD power that plugs into the Comma harness is optional and is used to keep the Comma powered after you turn off the ignition. Use the OBD at your own risk with the Lightning's tiny 12 volt battery.

 

[Ajzride]

The coupler was not designed to be used with a 5v power supply. It was tuned for 12v in the car, I would expect weird things to happen on a 5v source.

 

[itsjmod]

Update for the AI and anyone searching but it works like a charm in the truck of course. Shouldn’t have worried bout it

Much better set up than the modified extension. Thanks for the help + info and for making these couplers guys

Comma set up is complete now finally after i hide the long cord

 

[kzoojason76]

Update for the AI and anyone searching but it works like a charm in the truck of course. Shouldn’t have worried bout it

Much better set up than the modified extension. Thanks for the help + info and for making these couplers guys

Comma set up is complete now finally after i hide the long cord

Now you can trade it in and have fun with the Comma 4!!! Happy New Year!

 

[UncleTony]

Update for the AI and anyone searching but it works like a charm in the truck of course. Shouldn’t have worried bout it

Much better set up than the modified extension. Thanks for the help + info and for making these couplers guys

Comma set up is complete now finally after i hide the long cord

Did your coupler case come split like that? It looks like it is starting to separate on the edge.

 

[tatanka]

How many people would be interested in a quick release dock for the C4? Comma claims it's more robust and can be left on the windshield 24/7.

I too would be interested

 

[B177y]

Did your coupler case come split like that? It looks like it is starting to separate on the edge.

My early version from the first batch of couplers was splitting like @itsjmod's when I received it. I wrapped a zip tie around it and it's been fine. Never thought anything else about it until this post. Possibly a manufacturing issue?

 

[UncleTony]

My early version from the first batch of couplers was splitting like @itsjmod's when I received it. I wrapped a zip tie around it and it's been fine. Never thought anything else about it until this post. Possibly a manufacturing issue?

I print the case myself is why I was asking. The original case was made from normal ASA, the newer cases use Glass filled ASA, which has locked in place well enough I haven't been gluing them. But if they are splitting apart, I need to change them so they stay together properly. They are press fit, so if they start coming apart, you can always press them back together as long as the ridge and mating surface isn't broken.

 

[Ajzride]

I too would be interested

I've been working on it for 3 days now:

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