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Remixed123

USB Power for Host Operation

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I am using the Tiva C LaunchPad as a USB host for a USB device that requires a small amount of power. The USB host connector for the Tiva C LaunchPad does not supply any power, so currently I am providing this via a breadboard, however to make my prototype cleaner I am wanting to supply power via the USB.

 

One suggestion I received was to short circuit SW3, and that this will provide the LaunchPad and also the USB host connector with power via the ICDI USB connector.

 

I wanted to get opinions about this solution, and whether anyone sees any potential issues?

 

Oh and if I was to do this....I am assuming I would do it by connecting the outer pins of the switch, while leaving the center pin alone???

 

Glenn.

 

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I suggest connecting the center pin to the outside pin.  This way if the switch is to the left it is still "off" for your application.  If you connect the outer two then the switch will always be "on".

 

Also look at adding the two resistors to PB0 and PB1 so you can monitor VBUS and ID with the USB peripheral.  Be aware this could put 5V on the boosterpack pins that aren't normally getting that much voltage.

 

Dellwood

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Thanks Dellwood.

 

I am also using the CC3000 booster, so would be concerned about pushing 5v through to it.

 

When you say the switch to the left will turn it off, is left towards the outside or inside of the board? I'm a little confused, as I want to make sure that I get power from the ICDI USB connector that then supplies the USB device/host connector, which would mean I would want to switch it to the inside of the board I would imagine.

 

Glenn.

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Ok, I just worked it out...the LaunchPad has writing on it, so I was able to determine the correct orientation for left and right. 

 

I have made the required changes and all is working fine.

 

Thanks again.

 

Glenn.

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Hi,

Are you guys talking about TM4C123GXL lauchpad host mode? If yes please suggest me how to use it in host mode.

 

I dont get it. How can i get power to the USB device connector side while acting as Host mode?

 

Thanks in advance.

 

Bala

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Hi Bala,

 

Not sure I could explain the above in any more detail than has already been explained.....anyone else willing to give it a go?

 

As for USB Host, there are really no short cuts. You need to understand how USB works and you need to understand the USB Library that comes with the Tiva C.

 

To understand USB, I recommend this resource - http://www.beyondlogic.org/usbnutshell/usb1.shtml

 

To understand the USB Library, you will find a bunch of examples that come with Tivaware and you will also need to read the Tivaware USB Library User Guide. 

 

Best of luck!

 

Glenn.

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I could not find any Host examples useful enough for me.

 

 

When none of the examples or supplied drivers cover what you are trying to do, it gets very tricky. You basically will need to develop your own custom driver, which is one of the more difficult things a developer ever has to do. What sort of device are you trying to connect to?

 

I am not sure on your level of expertise, but even if you are pretty experienced, you are going to have to set a few weeks aside for this task.

 

To start off, I'd recommend you select the closest example to your device and then altering the code till you can get it working. If you have some money to spend on this project, then I'd also recommend the following device....I wish I had one of these when I was developing a host driver.

 

Beagle 480 USB Protocol Analyzer - $1400 - http://www.totalphase.com/products/beagle_usb480/

 

You can also learn about your device by using the following software, but this does not help with trouble shooting the driver you will need to develop, it just lets you see how Windows views the device - USBlyzer - http://www.usblyzer.com/

 

Here is another book you might find useful: USB Embedded Hosts - http://www.amazon.com/USB-Embedded-Hosts-Developers-Guide/dp/1931448248

 

Glenn.

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