aredhel_vlsi
Member level 4
Hello people,
I am back to ask a question of general interest. It is tricky to answer but I would like to ask for your experience because it s hard for me to detect the cause, maybe you've come across it. I have an instrument (with a robotic arm) that is connected to my pc with usb cable. The usb data bus is also inside the arm, which might influence the connection. It seems that sometimes, (maybe due to the fact that the arm moves) the camera connection is lost. I noticed that the Data+ channel drops from 5V to 0V when I slightly move the arm. I was wondering how I can troubleshoot and overcome this difficulty. I know it could be may things. I examined seriously two scenarios:
1. A not robust usb cable (it seems that the response of the signal with the oscilloscope differentiates from one end to the other of the cable, ie. double signal frequency at the other end). The cable is comprised of four parts with connections. So the metallic connections might affect the voltage of the signal transferred? Possibly but decreasing the number of connection cables to two didn't help much in the signal response.
2. A not robust pcb that connects to the camera cable. Of course redesigning the pcb is an easy answer, but before putting effort and resources to that I would like to ask how you would approach it. It seems difficult to check it because the pcb has no hardware description, and there not many output pins on it and it's hard to measure every single pin that would be related.
On top of that, by connecting from one computer to another sometimes it fixes but doesn't guarantee it will work. Could be the computer, could be static electricity. I know it's a bit abrupt, but based on the above information what would you advise in the first place? Also by changing the power supply from 240V to 110V also affects the performance. Thus I'm inclined to believe that it's a pcb issue.
Have you encountered a similar case? Thank you in advance.
I am back to ask a question of general interest. It is tricky to answer but I would like to ask for your experience because it s hard for me to detect the cause, maybe you've come across it. I have an instrument (with a robotic arm) that is connected to my pc with usb cable. The usb data bus is also inside the arm, which might influence the connection. It seems that sometimes, (maybe due to the fact that the arm moves) the camera connection is lost. I noticed that the Data+ channel drops from 5V to 0V when I slightly move the arm. I was wondering how I can troubleshoot and overcome this difficulty. I know it could be may things. I examined seriously two scenarios:
1. A not robust usb cable (it seems that the response of the signal with the oscilloscope differentiates from one end to the other of the cable, ie. double signal frequency at the other end). The cable is comprised of four parts with connections. So the metallic connections might affect the voltage of the signal transferred? Possibly but decreasing the number of connection cables to two didn't help much in the signal response.
2. A not robust pcb that connects to the camera cable. Of course redesigning the pcb is an easy answer, but before putting effort and resources to that I would like to ask how you would approach it. It seems difficult to check it because the pcb has no hardware description, and there not many output pins on it and it's hard to measure every single pin that would be related.
On top of that, by connecting from one computer to another sometimes it fixes but doesn't guarantee it will work. Could be the computer, could be static electricity. I know it's a bit abrupt, but based on the above information what would you advise in the first place? Also by changing the power supply from 240V to 110V also affects the performance. Thus I'm inclined to believe that it's a pcb issue.
Have you encountered a similar case? Thank you in advance.