On Sat, May 28, 2022 at 09:28 PM, Colin Kaminski wrote:
Thank you Dave. I have noticed some strange behavior with my USB port.
If I cut the 5V from the USB will the computer still send data? I would like to monitor things while I am testing solar cells.?
Colin
K6JTH
I think you will find that if there is no power at the USB port, the micro controller will not open the data lines to the usb port. I came across this after my cack handed effort to replace D3 after an 'accident' I caused when trying to fix the serial port connection.? To replace it, I fitted a through the hole diode above the board, and inadvertently disconnected R7 which goes to pin 40 of the micro controller from the 5 volt line of the USB port. I think this connection allows the controller to sense that the USB port is connected. Once I repaired the damaged track, the serial port opened fine. Without that 5v input to R7 and pin 40 on the controller, it won't open.
I am working way beyond my vision and skill trying to fix this tiny unit. Surface mount is way beyond my ability.
