AM5728: Wakeup by USB touch screen

Bin,

Thanks. Seems it is a important feature as more and more Touch screen use USB interface, for some product use Touch Screen, and no other button on the enclosure, support USB wake up would be the only choice.

Before their product use UART touch screen, they will configure the UART pin into GPIO mode before entering idle mode, when there are signal from touch screen, it will wake up from GPIO interrupt, then configure back to UART in software.

Gavin the situation of USB interface only, do you have other recommended method to implement wake up to inherit their product shape?

Hi Tony,

What is the USB speed of the touch screen, super-, high- or full-speed?

Bin, 

It is Full-Speed.

Tony,

There won't be a solution unless the customer can modify the board. I am trying to work with the hardware team to see if we can attach a GPIO on DP or DM to sniff the USB remote wakeup signal, so that the GPIO pin can wake up the system. I will update you once I have the hardware solution. Please note that since this is a customized hardware, we don't provide software support, the customer has to implement the software for the GPIO wakeup by themselves.

Bin,

It comes into my mind also, but the DP/DM signal is +-400mV, so it can't be used to trigger GPIO directly, may need related circuit to implement it indirect. hope to hear good news from you from hardware team.

Yes, customer can modify board and software by themselves if it workable.