USB GPS


pmprog

DNF (Did Not Finish)
Joined
Apr 25, 2011
Messages
4,150
Well, you can download Redhat drivers, which is a zip that contains one .c file, a makefile, and a readme. Not sure how that would work through Android though.

Anyway, I've ordered it, and guess I'll see how I get on
 

DAP

Member
Joined
Aug 29, 2008
Messages
431
The biggest issue is that USB GPS devices are USB "Full Speed" devices that will not work directly with the large USB port. To use it, you will need either a USB OTG cable, mini-A to mini-B, or Micro-B, depending on what the GPS uses, if it has a hard wired cable, you will need a mini-A to full sized A adaptor. Or you will need a USB "High Speed" hub to connect between the large connector and the GPS.
 

ekianjo

Hardcore Member
Joined
May 7, 2012
Messages
8,261
Location
神戸市、日本 (Japan)
The biggest issue is that USB GPS devices are USB "Full Speed" devices that will not work directly with the large USB port. To use it, you will need either a USB OTG cable, mini-A to mini-B, or Micro-B, depending on what the GPS uses, if it has a hard wired cable, you will need a mini-A to full sized A adaptor. Or you will need a USB "High Speed" hub to connect between the large connector and the GPS.
what do you call full speed? usb 2,0?
 

Binky

Death's Steed
Staff member
Joined
May 28, 2003
Messages
6,989
Location
16A (TO)
Full speed is 1.1. Hi-speed is 2.0
Please use numbers then, "full speed" is really confusing. 
Problem is that USB2.0 includes all of low-speed, full speed and high-speed.

Stupid naming, but it really is more precise to use names.

Why should GPS receivers be high-speed anyway? They're serial devices really.
 

hedwards

Active Member
Joined
Oct 7, 2008
Messages
872
Full speed is 1.1. Hi-speed is 2.0
 Please use numbers then, "full speed" is really confusing.
 Problem is that USB2.0 includes all of low-speed, full speed and high-speed.

Stupid naming, but it really is more precise to use names.

Why should GPS receivers be high-speed anyway? They're serial devices really.
That's half true. USB 2.0 ports usually have chips for both the 1.1 speeds and another for the 2.0 speeds. AFAIK, the Pandora was designed in a way that it won't offer 1.1 speeds on the non-to-go port but will on the USB-to-go port. Unless I have that backwards in which case reverse that.

I'm not sure why a USB GPS receiver would be USB2.0, a lot of those devices worked just fine over a serial port connection, so I would wager that something is reversed here.
 

Binky

Death's Steed
Staff member
Joined
May 28, 2003
Messages
6,989
Location
16A (TO)
That's half true. USB 2.0 ports usually have chips for both the 1.1 speeds and another for the 2.0 speeds. AFAIK, the Pandora was designed in a way that it won't offer 1.1 speeds on the non-to-go port but will on the USB-to-go port. Unless I have that backwards in which case reverse that.

That's why its more precise to use names.

As I said,

USB2.0 includes all of low-speed, full speed and high-speed.
The Pandora's full-size port is not USB2.0 - it is purely USB high-speed
 

DAP

Member
Joined
Aug 29, 2008
Messages
431
Full speed is 1.1. Hi-speed is 2.0
Please use numbers then, "full speed" is really confusing. 
Having designed several USB devices, I will NEVER use the version numbers when I wish to describe the speed of a USB device. The numbers do not tell you the speed of the device.

USB 1.0 and USB 1.1 support "Low Speed" and "Full Speed"

USB 2.0 supports "Low Speed", "Full Speed" and "High Speed"

USB 3.0 supports "Low Speed", "Full Speed", "High Speed", and "Super Speed"

As you can see, I can make a "Low Speed" device and call it "USB 3.0".

The speed names are the only thing in the specification that have any meaning when referring to the speed the device is capable of.

The mistake that was made in the design of the Pandora is that the port they connected to the USB A connector was intended to be hard wired to a High Speed hub. Part of the specification of a high speed hub is that it is required to translate low speed and full speed transactions into high speed transactions. It is a violation of the USB 2.0 specification to not support low speed and full speed on a USB port. If you really know what you are doing, and aren't planning on selling your device to the public, you can get away with what was done on the Pandora. If you do this and sell it to the public, you will be endlessly explaining to your customers why the USB port is not working and how to work around the bug.

The USB A port on the Pandora is NOT a USB 2.0 port, it is a USB High Speed port.
 
Last edited by a moderator:

pmprog

DNF (Did Not Finish)
Joined
Apr 25, 2011
Messages
4,150
Interesting detail there DAP, thanks.

I always loved how "Full Speed" is no longer the fastest. Just like how "High Def" TV is only HD to the previous resolution, what's next "Super HD", "Mega HD", "UltraDef"? ;)
 

Binky

Death's Steed
Staff member
Joined
May 28, 2003
Messages
6,989
Location
16A (TO)
Maybe they should have gone Low --> high --> super --> hyper or something?
 
Top