I'm experiencing a strange problem:
I have a cheap usb camera (model SQ11 https://www.amazon.com/dp/B077CQDCN8).
When the camera is connected to a USB port after the RPI board has booted,
it is detected and works well.
But if the camera is already connected when the RPI board is powered on
(or rebooted), the camera is not detected.
I've tested it with RPI-Zero-wireless and RPI3A+.
Strangely, when testing on RPI3B and RPI3B+ it works fine even upon boot.
So I'm assuming it has something finicky with USB initialization
(perhaps because RPIzW/RPI3A+ have less capable USB hardware?).
I've tried adding "boot_delay" and "bootcode_delay" to config.txt,
they didn't solve the issue.
Any ideas? suggestion to try?
I tried to find ways to reset or power-cycle the USB power,
but couldn't find such anything for RPIzW/RPI3A+.
dmesg shows (when the camera is detected):
Code: Select all
$ lsusb Bus 001 Device 004: ID 1908:3272 GEMBIRD
(the camera includes a microphone and a microSD card reader, hence the detection of removable disk and audio device).
Code: Select all
# dmesg usb 1-1.5: new high-speed USB device number 5 using dwc_otg usb 1-1.5: config 1 interface 3 has no altsetting 1 usb 1-1.5: New USB device found, idVendor=1908, idProduct=3272 usb 1-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 1-1.5: Product: GENERAL - AUDIO usb 1-1.5: Manufacturer: Generic usb-storage 1-1.5:1.4: USB Mass Storage device detected scsi host0: usb-storage 1-1.5:1.4 scsi 0:0:0:0: Direct-Access Buildwin Media-Player 1.00 PQ: 0 ANSI: 4 sd 0:0:0:0: Attached scsi generic sg0 type 0 sd 0:0:0:0: [sda] Attached SCSI removable disk
The power supply is a 5V/2.5A, so not likely an over-current issue.