Forum | Documentation | Website | Blog

Skip to content
Snippets Groups Projects
Commit 9e5ef68f authored by Seth Nowlin's avatar Seth Nowlin :soccer:
Browse files

Delete relay.rst

parent 2ed2ac71
Branches
Tags
1 merge request!99Erasing the older Branch and Starting Anew...
Hide whitespace changes
Inline Side-by-side
Showing
with 0 additions and 351 deletions
boards/capes/relay.rst deleted 100644 → 0
+ 0
− 351
View file @ 2ed2ac71
.. _bone-cape-relay:
BeagleBoard.org BeagleBone Relay Cape
#####################################
A Relay Cape, as the name suggests, is a simple Cape with relays on it.
It contains four relays, each of which can be operated independently from the BeagleBone.
.. image:: images/BeagleBoneRelayCapeA2-400x274.png
:align: center
* `Order page <https://beagleboard.org/capes#relay>`_
* `Schematic <https://git.beagleboard.org/beagleboard/capes/-/tree/master/beaglebone/Relay>`_
.. note::
The following describes how to use the device tree overlay that is under development.
The description may not be suitable for those using older firmware.
Installation
************
No special configuration is required. When you plug the Relay Cape into your BeagleBoard,
it will automatically be recognized by the Cape Universal function.
You can check to see if the Relay Cape is recognized with the following command.
.. code-block::
ls /proc/device-tree/chosen/overlay
A list of currently loaded device tree overlays is displayed here.
If you see `BBORG_RELAY-00A2.kernel` in this list, it has been loaded correctly.
If it is not loaded correctly, you can also load it directly
by adding the following to the U-Boot options
(which can be reflected by changing the file /boot/uEnv.txt) to reflect the text below.
.. code-block::
uboot_overlay_addr0=BBORG_RELAY-00A2.dtbo
Usage
*****
.. code-block::
ls /sys/class/leds/
The directory "relay1", for instance, exists in the following directory.
The file brightness can be controlled by modifying it.
.. code-block::
echo 1 > relay1/brightness
This allows you to adjust the brightness file;
entering 1 for brightness turns it ON while entering 0 for brightness turns it OFF.
The four relays can be changed individually
by changing the number after "relay" in /sys/class/leds/relay.
Code to Get Started
*******************
<<<<<<< HEAD
<<<<<<< HEAD
Currently, using C files, libgpiod-dev in .c files, and
python3 files with the Relay Cape work well!
* For instance, a kernel that I found to work is kernel: `5.10.168-ti-r72`.
* Another idea, an image I found that works is `BeagleBoard.org Debian Bookworm IoT Image 2023-10-07`.
=======
Currently, using C/C++ files, libgpiod-dev/gpiod in .c files, and
python3 files with the Relay Cape work well!
* For instance, a kernel that I found to work is kernel: `5.10.168-ti-r77`
* Another idea, an image I found that works is `BeagleBoard.org Debian Bookworm IoT Image 2023-10-07`
>>>>>>> 2ac757d (update to relay.rst)
=======
Currently, using C/C++ files, libgpiod-dev/gpiod in C files, and
python3 files with the Relay Cape work well!
* For instance, a kernel that I found to work is kernel: `5.10.168-ti-r77`
* Another idea, an image I found that works is `BeagleBoard.org Debian Bookworm IoT Image 2023-10-07`
>>>>>>> 2ac757d (update to relay.rst)
There are newer images and kernels if you want to update and there are older ones in case you
would like to go back in time to use older kernels and images for the Relay Cape. Please remember
that older firmware will work differently on the BeagleBone Black or other related am335x
from beagleboard.org.
C Source with File Descriptors
******************************
<<<<<<< HEAD
<<<<<<< HEAD
You can name this file Bright.c and use gcc to handle compiling the source into a binary like so:
`gcc Bright.c -o Bright`
=======
You can name this file Relay.c and use gcc to handle compiling the source into a binary like so:
`gcc Relay.c -o Relay`
>>>>>>> 2ac757d (update to relay.rst)
=======
You can name this file Relay.c and use gcc to handle compiling the source into a binary like so:
`gcc Relay.c -o Relay`
>>>>>>> 2ac757d (update to relay.rst)
.. code-block::
/*
<<<<<<< HEAD
<<<<<<< HEAD
This is an example of programming GPIO from C on a BeagleBone Black or
other am335x board with the Relay Cape.
=======
This is an example of programming C using the specification interface on
a BeagleBone Black or other am335x board with the Relay Cape.
>>>>>>> 2ac757d (update to relay.rst)
=======
This is an example of programming C using the specification interface on
a BeagleBone Black or other am335x board with the Relay Cape.
>>>>>>> 2ac757d (update to relay.rst)
Use the Relay Cape attached to the BeagleBone Black for a change in seconds and then exit with CTRL-C.
The original source can be found here by Mr. Tranter: https://github.com/tranter/blogs/blob/master/gpio/part5/demo1.c
Jeff Tranter <jtranter@ics.com>
<<<<<<< HEAD
<<<<<<< HEAD
and...Seth. I changed the source a bit to fit the BeagleBone Black and Relay Cape while using the specification
made by the beagleboard.org people from their organization.
=======
and...Seth. I changed the source a bit to fit the BeagleBone Black and Relay Cape while using the new specification.
>>>>>>> 2ac757d (update to relay.rst)
=======
and...Seth. I changed the source a bit to fit the BeagleBone Black and Relay Cape while using the new specification.
>>>>>>> 2ac757d (update to relay.rst)
*/
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
int main()
{
// Export the desired pin by writing to /sys/class/leds/relay1/brightness
int fd = open("/sys/class/leds/relay1/brightness", O_WRONLY);
if (fd == -1) {
perror("Unable to open /sys/class/leds/relay1/brightness");
exit(1);
}
fd = open("/sys/class/leds/relay1/brightness", O_WRONLY);
if (fd == -1) {
perror("Unable to open /sys/class/leds/relay1/brightness");
exit(1);
}
// Toggle LED 50 ms on, 50ms off, 100 times (10 seconds)
for (int i = 0; i < 100; i++) {
if (write(fd, "1", 1) != 1) {
perror("Error writing to /sys/class/leds/relay1/brightness");
exit(1);
}
usleep(50000); // Kind of fast
if (write(fd, "0", 1) != 1) {
perror("Error writing to /sys/class/leds/relay1/brightness");
exit(1);
}
usleep(50000); // Kind of fast
}
close(fd);
// And exit
return 0;
}
C Source with gpiod.h and File Descriptors
***********************************************
<<<<<<< HEAD
<<<<<<< HEAD
Also...if you are looking to dive into the new interface, libgpiod-dev/gpiod, here is another form of
source that can toggle the same GPIO listed from the file descriptor.
=======
Also...if you are looking to dive into the new interface, libgpiod-dev/gpiod.h, here is another form of
source that can toggle the same "GPIO" listed from the file descriptor.
>>>>>>> 2ac757d (update to relay.rst)
=======
Also...if you are looking to dive into the new interface, libgpiod-dev/gpiod.h, here is another form of
source that can toggle the same "GPIO" listed from the file descriptor.
>>>>>>> 2ac757d (update to relay.rst)
One thing to note: `sudo apt install cmake`
1. mkdir GPIOd && cd GPIOd
2. nano LibGPIO.c
3. add the below source into the file LibGPIO.c
.. code-block::
// Simple gpiod example of toggling a LED connected to a gpio line from
// the BeagleBone Black and Relay Cape.
// Exits with or without CTRL-C.
// This source can be found here: https://github.com/tranter/blogs/blob/master/gpio/part9/example.c
<<<<<<< HEAD
<<<<<<< HEAD
// It has been changed by me, Seth, to handle the Relay Cape and the BBB Linux based SoC SBC.
// kernel: 5.10.168-ti-r72
=======
// It has been changed by me, Seth, to handle the Relay Cape and the BBB Linux based SiP SBC.
// kernel: 5.10.168-ti-r77
>>>>>>> 2ac757d (update to relay.rst)
=======
// It has been changed by me, Seth, to handle the Relay Cape and the BBB Linux based SiP SBC.
// kernel: 5.10.168-ti-r77
>>>>>>> 2ac757d (update to relay.rst)
// image : BeagleBoard.org Debian Bookworm IoT Image 2023-10-07
// type gpioinfo and look for this line: line 20: "P9_41B" "relay1" output active-high [used]
// That line shows us the info. we need to make an educated decision on what fd we will use, i.e. relay1.
// We will also need to locate which chipname is being utilized. For instance: gpiochip0 - 32 lines:
// #include <linux/gpio.h>
#include <gpiod.h>
#include <stdio.h>
#include <unistd.h>
int main(int argc, char **argv)
{
const char *chipname = "gpiochip0";
struct gpiod_chip *chip;
struct gpiod_line *lineLED;
int i, ret;
// Open GPIO chip
chip = gpiod_chip_open_by_name(chipname);
if (!chip) {
perror("Open chip failed\n");
return 1;
}
// Open GPIO lines
lineLED = gpiod_chip_get_line(chip, 20);
if (!lineLED) {
perror("Get line failed\n");
return 1;
}
// Open LED lines for output
ret = gpiod_line_request_output(lineLED, "relay1", 0);
if (ret < 0) {
perror("Request line as output failed\n");
return 1;
}
// Blink a LED
i = 0;
while (true) {
ret = gpiod_line_set_value(lineLED, (i & 1) != 0);
if (ret < 0) {
perror("Set line output failed\n");
return 1;
}
usleep(1000000);
i++;
}
// Release lines and chip
gpiod_line_release(lineLED);
gpiod_chip_close(chip);
return 0;
}
4. mkdir build && touch CMakeLists.txt
5. In CMakeLists.txt, add these values and text via nano or your favorite editor!
.. code-block::
cmake_minimum_required(VERSION 3.22)
project(gpiod LANGUAGES C)
add_executable(LibGPIO LibGPIO.c)
target_link_libraries(LibGPIO gpiod)
6. cd build && cmake ..
7. make
8. ./LibGPIO
.. code-block::
#!/usr/bin/python3
# Getting help from #beagle on IRC
# You know who you are currently!
from pathlib import Path
from time import sleep
class Gpio:
def __init__(self, name):
self.name = name
self._value_path = Path('/sys/class/leds/', name, 'brightness')
def get(self):
return int(self._value_path.read_text())
def set(self, value):
self._value_path.write_text(str(value))
relay_one = Gpio('relay1/')
relay_one.set('1')
sleep(2)
relay_one.set('0')
sleep(2)
These are a few examples on how to use the RelayCape and am335x supported BeagleBone Black SBC.
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment

Open hardware computers for makers, educators and professionals