Python GPIO Library for the Rock64 (R64.GPIO)

[edupv]

I'd like to report my test on the interrupt of the GPIO, I wish this will be help for the development.


Hardware : Rock64 4GB (Rock64 V2 2017-0713)
Software : bionic-minimal-rock64-0.6.31-209-arm64 (kernel 4.4.120).


I tried interrupts with gpio-int-test.c on physical pin 16 (GPIO3_A5):

Code:

root@rock64:~# ./gpio-int-test 101

poll() GPIO 101 interrupt occurred
..
poll() GPIO 101 interrupt occurred

It had responses, but I found the followings :

1. once gpio-int-test started, pin 16 had already been pulled-up internally to 3.2 V.
   
2. it was difficult for me to pull-down the pin. With a 20K resistor pull-down to ground, interrupt was triggered repeatedly. With a 10K resistor, pin voltage became 0.443V, and it became more stable. When I opened the 10K resistor, interrupt was triggered.
   

The problem is : 
10K pull-down resistor is quite small, and even with the 10K resistor, the pin voltage is still 0.443V, not close 0V. There should be something wrong.