Cheap Usb Power

[Dukie 'n' Dad]

Wanted to run my Vista C in the car and not have to use the batteries. All I wanted was some way to power the USB via the car's power port (formerly known as Cigarette Lighter Port).

 

Found a great solution.

 

http://www.ecost.com/ecost/shop/detail.asp?dpno=156575

 

This is just one of many vendors who carry the product. Works great, and uses standard USB cables. In fact, I carry just one cable, the same one I connect my PC to the GPS. This particular solution is less than $5 plus shipping. Works great.

[+tirediron]

Neat, I didn't realize you could provide external power via the USB, I thought you had to use the old Garmin round-plug connector for that.

[+Team DEMP]

Hmmmm - I just connected the USB cable from my computer to my 76CS and the battery display stays and doesn't switch to show it's being extenally powered.

 

Does your display switch?

[Dukie 'n' Dad]

On my Vista C, YES. When you supply a USB connection that also supplies power, on the top of the main menu the battery meter turns into a 'plug' symbol. Also on the light level pop-up, the bottom bar shows either battery meter or 'plug' symbol. depending on the power source. Please note that the Main Menu display is included in the latest firmware upgrade.

 

So, is this not so with the 76cs? What about the 60 series?

 

Please note that not all computers with USB ports supply power, you need a version 1.1 compliant or better USB port.

Edited September 23, 2004 by Dukie 'n' Dad

[+Renegade Knight]

...you need a version 1.1 compliant or better USB port.

Is that different from USB 2.0? Or are the type of USB port and the USB standard different?

[Dukie 'n' Dad]

USB 2.0 is several revisions ahead of 1.1. So, yes, a 2.0 supplies power.

[+Team DEMP]

So, is this not so with the 76cs? What about the 60 series?

I plugged the USB connector into the USB port on my notebooks docking station and then directly into a USB port in my notebook and neither of them changed the battery indicator to the plug. Plugging in the serial/AC connector into the serial plug on the back of the 76CS changed the battery indicator to a plug indicator.

 

My notebook is not USB 2.0.

[+greengolftee87]

from what i understand i think that the 60c and 76c suck too much power for a mini usb but the legend and vista dont

[+Andy and Robin]

But they are all powered by two AA batteries...

[+NightPilot]

Some PC USB ports deliver power and some don't. One computer at work has 2 USB ports, in the same manifold, and they're different. One will charge my Palm, and the other won't. I have to look in the back and check which of the two ports I plug into. The nice thing about standards is that there are so many of them.

[robertlipe]

Some PC USB ports deliver power and some don't.  One computer at work has 2 USB ports, in the same manifold, and they're different.  One will charge my Palm, and the other won't.  I have to look in the back and check which of the two ports I plug into.  The nice thing about standards is that there are so many of them. 

Well, fortunately, in this case, the standards specify exactly now many millamps the target can expect to receive in an unenumerated state (500, IIRC) and how the target can specify how many it requires (the descriptors on my 60 specify "zero", indicating it's self-powered) , the host is free to reject enumerating targ devices based on the currently available power budget, and how the host serial port indicates available power on a given USB port to manage the power budget on a given bus. These factors combined make it easy for those in the know with the right tools to know if a given device should work or not. (I consider it one of the biggest mistakes of the USBDIWG to allow non-powered hubs...)

 

The 60C's and 76's don't get power from USB (and don't claim to by looking at the descriptors) but theVistaC and SummitC apparently do. I haven't looked at the USB descriptors on those device, but will be happy to do so for analysis if someone sends me a dump or an eval unit to stick on my protocol analyzer.

 

While it's fun (and easy) to poke at those that form industry standards, be sure your blame is well placed.

[HawkesNest]

On my Vista C, YES. When you supply a USB connection that also supplies power, on the top of the main menu the battery meter turns into a 'plug' symbol. Also on the light level pop-up, the bottom bar shows either battery meter or 'plug' symbol. depending on the power source. Please note that the Main Menu display is included in the latest firmware upgrade.

 

My Legend C also shows the plug symbol when connected to the USB power. I have also noticed that the backlight always stays on too and doesn't time out when connected to the USB power.

[Dukie 'n' Dad]

I also like the little countdown timer that will shut off the unit if the USB loses power. Just hit any button to keep the unit alive.

[+Team DEMP]

The 60C's and 76's don't get power from USB (and don't claim to by looking at the descriptors) but theVistaC and SummitC apparently do.

Thanks for that info!! At least we know where each unit stands now.