As defined by the USB Spec the USB Slave (CX3) cannot notify the master (PC) of its own. The PC must ping the CX3 of its own if it wants to know any interrupt status.
This can be done by sending a vendor command by the PC (with direction IN, meaning PC is expecting data from the CX3), to which the CX3 replies in the Data phase.
Hi Madhu Sudhan,
Thank you very much for your clear answer.
Does Cypress has a complete example supporting hardware triggered still image capture? I went through V4L2 documentation, but couldn't find anything that related to monitoring/scanning the status interrupt from the UVC device.
I found that libusb has a function for interrupt transfer. I wonder if I could mix V4L2 with libusb function calls. I read somewhere that an interface can only be opened by one lib.
We do not have a complete working example for hardware trigger method of still image capture. But we can provide some guideliens on this.
Please refer to the attached document which gives an overview on the methods used to obtain still image.
I assume you are going to use the method 1 ( hardware trigger) which requires only minimal changes in the firmware and descriptor file.
- Madhu Sudhan
PRAG-032.docx 24.2 K