04-30-2018, 09:46 PM
If you are connecting a serial console to "ROCK64"
"Rock64 Boot-up Bug with Serial Console Cable"
https://forum.pine64.org/showthread.php?tid=5008
See the above thread.
Because "ROCK64" itself has individual differences,
Although it is not necessarily said that this condition inevitably occurs,
That possibility is high.
Because I experienced similar symptoms,
In my case, the following measures were taken to avoid this problem.
To connect the serial console (TX / RX) and "ROCK64", insert the Device:"74HC4050".
Basically, it is the same as the countermeasure introduced above.
- -
*) There is no input clamp-protection diode in "74HC4050".
*) Get power of "74HC4050" from "VCC_IO@ROCK64".
*) As a result of the above, isolation can be obtained even when the power of "ROCK64" is OFF.
"Rock64 Boot-up Bug with Serial Console Cable"
https://forum.pine64.org/showthread.php?tid=5008
See the above thread.
Because "ROCK64" itself has individual differences,
Although it is not necessarily said that this condition inevitably occurs,
That possibility is high.
Because I experienced similar symptoms,
In my case, the following measures were taken to avoid this problem.
To connect the serial console (TX / RX) and "ROCK64", insert the Device:"74HC4050".
Basically, it is the same as the countermeasure introduced above.
- -
*) There is no input clamp-protection diode in "74HC4050".
*) Get power of "74HC4050" from "VCC_IO@ROCK64".
*) As a result of the above, isolation can be obtained even when the power of "ROCK64" is OFF.