Hi,
O.K. I have distilled it down to copy and paste. This should give you a PWM
with 25% duty cycle at 10khz. The graph should look like the attached
picture.
1) include this dtsi file at the end of your XXX.dtb
&am33xx_pinmux {
pwm_P8_P13: pinmux_pwm_P8_P13_pins {
pinctrl-single,pins = <0x024 0xC>;
};
};
&ocp {
P8_13_pinmux {
status = "disabled";
};
epwmss@48304000 {
status = "okay";
ehrpwm@48304200 {
status = "okay";
};
};
pwm_test_P8_13 {
compatible = "pwm_test";
pwms = <&ehrpwm2 1 100000 1>;
pwm-names = "PWM_P8_13";
pinctrl-names = "default";
pinctrl-0 = <&pwm_P8_P13>;
enabled = <1>;
duty = <25000>;
status = "okay";
};
};
2) Compile the pwm_test.c into a pwm_test.ko by following instructions
from:
https://github.com/SaadAhmad/beaglebone-black-cpp-PWM
and installing as a kernel module.
3) You should get:
/sys/devices/ocp/ocp:pwm_test_P8_13# ls -l
total 0
lrwxrwxrwx 1 root root 0 Jan 4 19:09 driver ->
../../../bus/platform/drivers/pwm_test
-rw-r--r-- 1 root root 4096 Jan 4 19:09 driver_override
-rw------- 1 root root 4096 Jan 4 19:09 duty
-r--r--r-- 1 root root 4096 Jan 4 19:09 modalias
-rw------- 1 root root 4096 Jan 4 19:09 period
-rw------- 1 root root 4096 Jan 4 19:09 polarity
drwxr-xr-x 2 root root 0 Jan 4 19:09 power
-rw------- 1 root root 4096 Jan 4 19:09 run
lrwxrwxrwx 1 root root 0 Jan 4 19:09 subsystem -> ../../../bus/platform
-rw-r--r-- 1 root root 4096 Jan 4 18:56 uevent
And you can echo 10000 > duty
or
echo 100000 > period
To change the PWM.
Best, Mike.
--
For more options, visit http://beagleboard.org/discuss
---
You received this message because you are subscribed to the Google Groups
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
