No such thing as a small change | |
PerlMonks |
comment on |
( [id://3333]=superdoc: print w/replies, xml ) | Need Help?? |
Rewriting your code like this should help Thank you... There's a definition issue on read_file but that is unused so I have commented it out to test it. As I expected, but cannot explain, your code works as expected provided the GPIO is already exported. Your export code doesn't work and fails with Could not open /sys/class/gpio/gpio20/direction: Permission denied at afoken.pl line 12. The module I am creating has the same issue. In it's constructor I am exporting the two GPIO pins - except I cannot do it by writing to the psuedo files. The only way I have found thus far is a system call to the gpio utility. If I uncomment the four lines at the start of sub new, then it works if the GPIO pins are already exported. This bit of code does not export them although I do not get an error here. I get an error further down the line when I try to change them. Making the system calls works well because I can initialise the state at the same time but I was still wanting to avoid system if I could... Perhaps that will be a later update to the software! In reply to Re^13: Controlling USB on Raspberry Pi
by Bod
|
|