EBC Exercise 10 Flashing an LED - Revision history

Rickb777: /* Flashing the user LEDs */

2013-04-02T21:21:40Z

‎Flashing the user LEDs

2013-04-02T21:15:38Z

‎gpio via the Shell Command Line and sysfs

2013-04-02T21:15:08Z

‎gpio via the Shell Command Line and sysfs

2013-04-02T21:14:52Z

‎gpio via the Shell Command Line and sysfs

2012-09-18T08:18:54Z

2012-09-18T08:18:38Z

Typo correction.

2012-09-13T01:23:44Z

‎Analog in - bone

2012-09-11T04:02:29Z

Typo correction

2012-09-09T17:55:27Z

‎Analog in - bone

2012-09-04T21:17:00Z

‎Analog in - bone

@@ Line 54: / Line 54: @@
   none nand-disk mmc0 [heartbeat]
-This shows trigger can have 4 values.  The present value is '''heartbeat'''.  Check the LED, is the beating?  You can stop the heartbeat via:
+This shows trigger can have 4 values.  The present value is '''heartbeat'''.  Check the LED, is it beating?  You can stop the heartbeat via:
   beagle$ '''echo none > trigger'''

@@ Line 9: / Line 9: @@
 ('''Note''':  Draw the new diagrams with [http://engineersofthecorn.blogspot.com/2012/06/fritzing-part-for-beaglebone.html this].)
-The easiest way to do general purpose I/O (gpio) on the Beagle is through a terminal window and a shell prompt. In Linux, almost everything is treated as a file.  Even things that aren't files. In our class we'll use a virtual file system called '''sysfs'''.  sysfs exposes the drivers for the hardware so you get easily use them.
+The easiest way to do general purpose I/O (gpio) on the Beagle is through a terminal window and a shell prompt. In Linux, almost everything is treated as a file, even things that aren't files. In our class we'll use a virtual file system called '''sysfs'''.  sysfs exposes the drivers for the hardware so you get easily use them.
 Try this, open a terminal and type:

@@ Line 9: / Line 9: @@
 ('''Note''':  Draw the new diagrams with [http://engineersofthecorn.blogspot.com/2012/06/fritzing-part-for-beaglebone.html this].)
-The easiest way to do general purpose I/O (gpio) on the Beagle is through a terminal window and a shell prompt. In Linux almost everything is treated as a file.  Even things that aren't files. In our class we'll use a virtual file system called '''sysfs'''.  sysfs exposes the drivers for the hardware so you get easily use them.
+The easiest way to do general purpose I/O (gpio) on the Beagle is through a terminal window and a shell prompt. In Linux, almost everything is treated as a file.  Even things that aren't files. In our class we'll use a virtual file system called '''sysfs'''.  sysfs exposes the drivers for the hardware so you get easily use them.
 Try this, open a terminal and type:

@@ Line 9: / Line 9: @@
 ('''Note''':  Draw the new diagrams with [http://engineersofthecorn.blogspot.com/2012/06/fritzing-part-for-beaglebone.html this].)
-The easiest way to do general purpose I/O (gpio) on the Beagle is through a terminal window and a shell prompt. In Linux most everything is treated as a file.  Even things that aren't files. In our class we'll use a virtual file system called '''sysfs'''.  sysfs exposes the drivers for the hardware so you get easily use them.
+The easiest way to do general purpose I/O (gpio) on the Beagle is through a terminal window and a shell prompt. In Linux almost everything is treated as a file.  Even things that aren't files. In our class we'll use a virtual file system called '''sysfs'''.  sysfs exposes the drivers for the hardware so you get easily use them.
 Try this, open a terminal and type:

@@ Line 3: / Line 3: @@
 {{YoderHead}}
-The [http://en.wikipedia.org/wiki/Hello_world_program "Hello World"] program is the traditional first program for many classes.  Flashing an LED is the embedded equivalent.  Here we will explore a few ways to flash and LED on the Beagle and explore General Purpose I/O (gpio) along the way.  Thiese calls will be done from the command line of the Beagle, so there is no need for the host computer.
+The [http://en.wikipedia.org/wiki/Hello_world_program "Hello World"] program is the traditional first program for many classes.  Flashing an LED is the embedded equivalent.  Here we will explore a few ways to flash and LED on the Beagle and explore General Purpose I/O (gpio) along the way.  These calls will be done from the command line of the Beagle, so there is no need for the host computer.
 == gpio via the Shell Command Line and sysfs ==

@@ Line 222: / Line 222: @@
 I used '''Ctrl-C''' to interrupt since it already found what I wanted.
-  beagle$ '''cd /sys/devices/platform/omap/tsc'''
+  beagle$ '''cd /sys/devices/platform/tsc'''
   beagle$ '''ls'''
   ain1  ain3  ain5  ain7  driver    power      uevent

@@ Line 201: / Line 201: @@
 * Can you modify the scripts above to read the switch and turn the LED on and off?
-* Rewire your switch to work will a pullup resistor.
+* Rewire your switch to work with a pullup resistor.
 == Analog in - bone ==

@@ Line 216: / Line 216: @@
   beagle$ '''find / -name ain5'''
-  /sys/devices/platform/omap/tsc/ain6
+  /sys/devices/platform/omap/tsc/ain5
-  /sys/kernel/debug/omap_mux/ain6
+  /sys/kernel/debug/omap_mux/ain5
   '''^C'''

@@ Line 207: / Line 207: @@
 (This is based on [http://www.gigamegablog.com/2012/01/22/beaglebone-coding-101-using-the-serial-and-analog-pins/ this].)
-The bone has eight Analog Inputs.  Several are exposed on P9.  They are labeled '''AIN''' in table 11 above.  How many to you find?
+The bone has eight Analog Inputs.  Several are exposed on P9.  They are labeled '''AIN''' in table 11 above.  How many do you find?
 The AIN pins are sampled at 12 bits and 100k samples per second.  The input voltage is between 0 and 1.8V.  Fortunately, both voltages are available on P9.