Embedded System Tutorial File I/O - Revision history

Sree at 20:10, 25 January 2019

2019-01-25T20:10:02Z

Proj user6: /* Assignment */

2016-03-18T14:09:10Z

‎Assignment

Proj user6: /* Assignment */

2016-03-18T14:08:54Z

‎Assignment

Proj user1 at 08:02, 30 April 2015

2015-04-30T08:02:42Z

Preet: /* Assignment */

2015-04-21T22:52:09Z

‎Assignment

Preet at 23:59, 29 May 2014

2014-05-29T23:59:49Z

Preet at 01:06, 10 May 2014

2014-05-10T01:06:37Z

Preet: /* Assignment */

2014-05-10T01:06:11Z

‎Assignment

Preet: /* Assignment */

2014-05-10T01:01:49Z

‎Assignment

Preet: /* Assignment */

2014-05-10T00:59:56Z

‎Assignment

← Older revision		Revision as of 20:10, 25 January 2019
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		+	Socialledge is moving to two portals.
		+	* The Wiki will remain here for general references about the SJ-One board, and to document student reports.
		+	* The bookstack will now be used for SJSU assignments
		+
		+	[http://books.socialledge.com/books/embedded-drivers-real-time-operating-systems/chapter/lesson-watch-dogs This article has been moved here]
		+
		+	<!--
		+
	In this project, we will attempt to "combine" all the FreeRTOS knowledge into a single assignment.		In this project, we will attempt to "combine" all the FreeRTOS knowledge into a single assignment.

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	What you created is a "software watchdog". This means that in an event when a loop is stuck, or a task is frozen, you can save relevant information such that you can debug at a later time.		What you created is a "software watchdog". This means that in an event when a loop is stuck, or a task is frozen, you can save relevant information such that you can debug at a later time.
		+	-->

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 #*  If you fail to detect the bits are set, that means that the other tasks did not reach the end of the loop.
 #*  In the event of failed to detect the bits, append a file (stuck.txt) with the information about which task may be "stuck"
 #*  Extra Credit: Every sixty seconds, save the CPU usage info to a file named "cpu.txt".  See terminal command "infoHandler" for reference.  Open the file, write the file, and close it immediately so the data is immediately flushed.
 #  Create a terminal command to "suspend" and "resume" a task by name.
 #*  "task suspend task1" should suspend a task named "task1"

@@ Line 24: / Line 24: @@
 #  Create a '''<code>watchdog task</code>''' that monitors the operation of the two tasks.
 #*  Use high priority for this task.
 #*  Use a timeout of 1 second, and wait for all the bits to set.  If there are two tasks, wait for bit1, and bit2 etc.
 #*  If you fail to detect the bits are set, that means that the other tasks did not reach the end of the loop.
 #*  In the event of failed to detect the bits, append a file (stuck.txt) with the information about which task may be "stuck"
 #*  Open the file, append the data, and close the (stuck.txt) file to flush out the data immediately.
 #  Create a terminal command to "suspend" and "resume" a task by name.

← Older revision		Revision as of 08:02, 30 April 2015
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−	After completing the assignment, you will get a ~~sensor~~ of how the CPU is utilized, and how to use a new FreeRTOS event group API. All together, you should ~~acheive~~ a better sense of designing your tasks and using the File I/O for debugging purposes.	+	After completing the assignment, you will get a sense of how the CPU is utilized, and how to use a new FreeRTOS event group API. All together, you should achieve a better sense of designing your tasks and using the File I/O for debugging purposes.

@@ Line 10: / Line 10: @@
 #  Create a '''<code>producer task</code>''' that takes 1 light sensor value every 1ms.
-#*  Collect the average of the 100 readings.
+#*  After collecting 100 samples (after 100ms), compute the average.
 #*  Write average value every 100ms (avg. of 100 samples) to the '''<code>sensor queue</code>'''.
 #*  Use medium priority for this task
@@ Line 17: / Line 17: @@
 #*  Open a file (sensor.txt), and append the data to an output file on the SD card.
 #*  Save the data in this format: '''<code>printf("%i, %i\n", time, light)"</code>'''
-#*  Just leave the file in "open" mode, such that it will flush the data after enough data is written rather than flushing it upon each write, which will consume a lot of CPU.
+#*  Note that if you write and close a file every 100ms, it may be very inefficient, so try to come up with a better method such that the file is only written once a second or so...
 #*  Use medium priority for this task
 #  At the end of the loop of each task, set a bit using FreeRTOS event group API.

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 #  Suspend the producer task.  The watchdog task should display a message and save relevant info to the SD card.
 #  Let the system run for a while, and note down the CPU usage in your text file.
 What you created is a "software watchdog".  This means that in an event when a loop is stuck, or a task is frozen, you can save relevant information such that you can debug at a later time.

← Older revision		Revision as of 01:06, 10 May 2014
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−	After completing the assignment, you will get a sensor of how the CPU is utilized, and how to use a new FreeRTOS event group API. All together, you should acheive a better ~~sensor~~ of designing your tasks and using the File I/O for debugging purposes.	+	After completing the assignment, you will get a sensor of how the CPU is utilized, and how to use a new FreeRTOS event group API. All together, you should acheive a better sense of designing your tasks and using the File I/O for debugging purposes.

@@ Line 1: / Line 1: @@
 In this project, we will attempt to "combine" all the FreeRTOS knowledge into a single assignment.
 == Assignment ==
 Please follow the steps precisely in order to complete the objectives of the assignment.  If you use the C++ FreeRTOS framework, it should make the assignment significantly easy.
 #  Create a '''<code>producer task</code>''' that takes 1 light sensor value every 1ms.
@@ Line 32: / Line 37: @@
 #  Let the system run for a while, and note down the CPU usage in your text file.
 #  Change the ADC sensor implementation
-#*  Modify the source code of how the light sensor class obtains the ADC value by not using ADC polling mode.
+#*  Modify the source code of '''<code>"adc.h"</code>''' by not using ADC polling mode.
 #*  Instead of "trigger ADC", "wait for completion", and "read value", modify it to this:
-#*:  Upon ADC initialization, enable ADC interrupt, which should "give" a semaphore.
+#*:  Upon ADC initialization, enable ADC interrupt, and create a binary semaphore.
-#*:  After triggering the ADC, wait for ADC semaphore to be given, and then read the value.
+#*:  The ADC interrupt should "give" the semaphore upon completion of the ADC.
 #  After changing the ADC behavior, let the system run for a while, and note down the CPU usage again.
 What you created is a "software watchdog".  This means that in an event when a loop is stuck, or a task is frozen, you can save relevant information such that you can debug at a later time.