====== Hardware PWM ======
----

**ODROID-C2** Has two possible PWM ports.

Starting from [[c2_ubuntu_release_note_v1.1|Ubuntu Release (v1.1)]] or a kernel update performed on 2016-02-26 or later includes the PWM support.


===== Usage =====
For pin position, numbers and names, please refer to the pinmap [[http://odroid.com/dokuwiki/doku.php?id=en:c2_hardware#expansion_connectors|Expansion Connector]]
=== Option 1: Single PWM ===
The code below loads the PWM module with a single PWM and the PWM controller module.

//**PWN PIN: 33**//

<code>
sudo modprobe pwm-meson
sudo modprobe pwm-ctrl
</code>


=== Option 2: Two PWMs ===
//**PWM PINS:**//

//**PWM0: 33**//

//**PWM1: 19**//

<code>
sudo modprobe pwm-meson npwm=2
sudo modprobe pwm-ctrl
</code>

<WRAP left round important 100%>
If you are using TWO pwm setup, PWM1 & SPI can not be used simultaneously.\\
Because GPIOX_7(pin19) has two function spi_mosi & pwm.
</WRAP>

==== Examples of usage ====
You can control this pwm via simple sysfs entries.

On **/sys/devices/platform/pwm-ctrl/** You'll find the following files:

==== duty0 ====
Duty cycle of 1023 (10bit resolution)  <code>echo 102 > duty0</code> will result in 102/1023 (approx 10%) of Duty cycle.\\ \\
<code>echo 512 > duty0</code> will result 50:50 of Duty cycle.

==== enable0 ====
Enable/Disable this PWM <code>echo 1 > enable0</code> Will enable this PWM <code>echo 0 > enable0</code> Will disable this PWM.

==== freq0 ====
This is the PWM Frequency in Hertz! <code>echo 100000 > freq0</code> This will set the frequency to 100kHz

**Maximum Frequency is 1Mhz.**

On PWM0 you can test higher frequencies. There are not guarantee's!
1Mhz is what we support. 


<WRAP left round important 100%>
If you are using TWO pwm setup, You have:
enable0, freq0, duty0 __AND__
enable1, freq1, duty1
</WRAP>

==== How to access the PWM port in C language ====

[[http://forum.odroid.com/viewtopic.php?f=141&t=25563#p177696|Example code by paulcrawford ]]