Power from car's USB port

[Frank Farrell]

My Toyota Auris has a built-in USB port and I prefer to use that to power my XL instead of the cigar lighter adapter;
But every time I connect my TomTom to the USB it thinks that it is connecting to a computer and takes some time before it pops up the message "Do you want to connect to a computer?"
I just press "No" and everything works fine after that until I switch off the ignition, when I switch on again it goes through the same search process which sometimes takes 10 minutes

Is there any way I can change the default setting so that it just accepts USB power?

Many Thanks

Model XL IQ Routes edition

 

[dhn]

Interesting. I don't think so. I believe it's built into the hardware of the device how to determine the power method it is getting. A cigarette lighter provides 1A or more power while a usb port on the computer is .5A. I guess a USB port in the car is providing the same .5A so the device 'thinks' it is being connected to a computer.

I know that here in North America, one can buy a device that fits into the cig lighter such that not only is there a cig lighter port but, as well, a USB port. Maybe you can find such a device where you are......

 

[tgold]

When I plug an XXL into a notebook USB socket I am asked by the TomTom whether I wish to connect it to the computer but when I connect the same lead to one of these http://burnsmoto.com/img/Mini_USB_Car_Charger.jpeg I am not asked that question. This suggests that if you can find a power only USB cable - i.e. not capable of handling data - it will do the job.

 

[canderson]

My Toyota Auris has a built-in USB port and I prefer to use that to power my XL instead of the cigar lighter adapter;
But every time I connect my TomTom to the USB it thinks that it is connecting to a computer and takes some time before it pops up the message "Do you want to connect to a computer?"

Your Auris evidently has a USB port not just for charging, but for moving data (music) to your car audio system. Since the TomTom sees a data connection (not just power), it's trying to make a connection. Nothing to be done for that except to say "No".

 

[jules46]

Hi I had a similar problem with a usb feed on a Hyundi !30 and heard of similar problems using that port as the TomTom seems-to think it was connecting to a computer. Eventually solved the problem by playing around with connection routines, think it solved by connecting after the car had been started but not certain.

Good luck

 

[Frank Farrell]

Thanks for the replies Guys!

The reasons for using the USB port are (1) it's in the glove compartment so the wire is a short run, The socket is located between the front seats and the wire tends to get in the way (2) the single lighter socket is used for other stuff on long runs,
if it was just a matter of selecting "Yes" when asked if I want to connect to a computer there would be no problem but the TomTom first conducts a search for a non-existent computer running TomTom Home that seems to take forever, sometimes we are well into our journey before it wakes up and smells the coffee

 

[canderson]

It's actually not looking for a computer running Home (it doesn't know or care about Home), it's trying to negotiate a USB session with a USB host that is willing to talk to it. And actually, you'd want to say "No" to the connection question!

 

[Andy_P]

There are four pins in the USB plug - two for power and two for data.
The way the TomTom decides whether there is a computer on the end of the USB cable is by looking at the data pins.
It gets a bit complicated, but in essence a dedicated charger will just have a dead short (or possibly a 200ohm resistance) across the two data pins, anything else and the TomTom will think there is a computer or other host upstream.

I've heard of some simple charging circuits where there is nothing connected to the data pins, and those can be fixed with a suitable shorting link or resistor, but if your car DOES have some intelligence on the other end of the USB feed, you'll either have to live with it, or you could try making a dedicated lead to feed the TomTom, which disconnects the data lines and terminates them instead.

(Edited for new info)