USB Communication

[amel1234]

Hello,

I have a problem with usb communication. you will find attached the schematic.
can anyone give me where is the problem?
thank you.

Regards

 

[KlausST]

Hi,

there are several issues.

1) you don´t state "which" problem you have
2) you don´t specify the USB version (speed) you designed it for. (USB1.1 / USB 2.0 / USB3.0 ...)
3) you need to read and follow the USB specification according signal treatment
especially:
* characteristic impedance of signal lines
* connectors according USB_specification. Banana jacks are not suitable for any USB signals
* the data lines are not specified to drive LEDs (and your eyes surely can´t follow the fast pulses)
* pulled up / pulled down data lines define the USB_device speed grade

Klaus

 

[amel1234]

Klaus,
thank you so much for your response. the usb is USB2.0 low speed. the problem is that there is no USB communication with this schematic and there is no power in D+ and D-.
I am a beginner in hardware design so thank you so much for the informations that you give it to me and I will take it in consideration

 

[KlausST]

Hi,

for sure there is no power, they are signal lines.

disconnect everything thet is connected to the D+ and D- lines.
There must be no: R, LED, banana ...

Klaus

 

[amel1234]

Hello,

There is somone (hardware engineer) who propose to me to use Schmitt Trigger with USB data line to drive Leds! I think that is not possible.
can you confirm to me this?

Thank you.

 

[FvM]

Could be an USB charging application where termination resistors respectively static voltage levels are used to signal a current demand.