I'm interested too!
I've built my own IR transmitter and i want to use GPIO to send signals.
I found gpio-ir-tx driver on my system and i can successfully load it with modprobe, but i can't figure out how to make it working, maube someone know who made this driver?
As far as i understood.
Need to create /boot/config.txt file with:
dtoverlay=gpio-ir-tx,gpio_pin=1 (or your pin)
Then need to create udev rule that creating symlink from gpio to /dev/lirc-tx but this is not happening for some reasonm i can't figure out why.
/etc/udev/rules.d/71-lirc.rules
ACTION=="add", SUBSYSTEM=="lirc", DRIVERS=="gpio_ir_recv", SYMLINK+="lirc-rx"
ACTION=="add", SUBSYSTEM=="lirc", DRIVERS=="gpio-ir-tx", SYMLINK+="lirc-tx"
ACTION=="add", SUBSYSTEM=="lirc", DRIVERS=="pwm-ir-tx", SYMLINK+="lirc-tx"
Couple questions.
1. Created by me file /boot/config.txt, is used during boot process or not?
2. Udev rule is not creating simlink to device, why?