EHRPWM LINUX DRIVER
I was able to get a 1. Currently there are no standard PWM driver for the Beagle, though a couple have been proposed  ,  and . Retrieved from ” https: If these command cause the SSH connection to close, you may have to get a newer version of Angstrom. I couldn’t set them during kernel boot with the 2. Try changing the frequency and duty cycle. If it isn’t you’ll have to recompile the Kernel and u-boot.
|Date Added:||18 July 2004|
|File Size:||17.70 Mb|
|Operating Systems:||Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/X|
|Price:||Free* [*Free Regsitration Required]|
Follow the instructions here if you aren’t set up for git.
This page was last edited on 31 Mayat This will show up at ehrpwm1A the 0 maps to A. How do you know which one to change?
Can you guess why? This is for the 3. What’s the highest frequency you can get?
If these command cause the SSH connection to close, you may have to get a newer version of Linuxx. I was able to get a 1.
In a previous exercise EBC Exercise 11 gpio Polling and Interrupts you saw how to use the gpio to produce a square wave out using a C program and sysfs. The standard way to interface with the outside world in Linux is through Kernel Drivers.
Stick a scope on the pin and see if the frequency and duty cycle are right.
You may have to set the duty cycle to 0 to change the frequency. There are two ways to do this, the slick way which may not work and the sure way. These MUXes are set at boot time, and must be set when the kernel boots, or in u-boot. In this exercise you will learn how to use the Beagle’s pulse eyrpwm modulation pwm hardware using the sysfs interface and also learn about pin multiplexing pin mux on the way.
There are some pins that you can control what they output. You’ll see something like:. Try changing the frequency and duty cycle. Embedded Linux Class by Mark A.
platform/amx/ti/drivers/ehrpwm.c – kernel/lk – Git at Google
Navigation menu Personal tools Log in Request account. Here’s another PWM lead.
Linux source code: drivers/pwm/pwm-tiehrpwm.c (v) – Bootlin
Although this approach works, it is really transitional until a standard can be established. Views Read View source View history. This says the MUX is presently set on pin 7. Now, check the settings by browsing to http: I couldn’t set them during kernel boot with the 2.
EBC Exercise 13 Pulse Width Modulation 3.2
The u-boot details are here. If it isn’t you’ll have to recompile the Kernel and u-boot. Counting starts on the left with 0. A given pin can have one from as many as eight lines assigned to it.