ECE497 BeagleBone PRU - Revision history

Yoder: Removed grade. Moved to Fall2012

2013-05-18T16:17:31Z

Removed grade. Moved to Fall2012

Yoder: /* Grading */

2012-11-14T20:41:33Z

‎Grading

Yoder: /* Future Work */

2012-11-14T20:22:56Z

‎Future Work

Yoder: /* Work Breakdown */

2012-11-14T20:22:07Z

‎Work Breakdown

Yoder: /* Highlights */

2012-11-14T20:21:45Z

‎Highlights

Yoder: /* Building and Running the Sin_Approximation Example */

2012-11-14T20:21:34Z

‎Building and Running the Sin_Approximation Example

Yoder: /* Sending an array to the PRU */

2012-11-14T20:21:07Z

‎Sending an array to the PRU

Yoder: /* How the C Code Works */

2012-11-14T20:19:57Z

‎How the C Code Works

Yoder: /* How the Assembly Code Works */

2012-11-14T20:06:16Z

‎How the Assembly Code Works

Yoder: /* Building and Running the GPIO_PWM_PRU Example */

2012-11-14T20:05:37Z

‎Building and Running the GPIO_PWM_PRU Example

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-[[Category:ECE497 |Project]]
+[[Category:ECE497Fall2012 |Project]]
 {{YoderHead}}
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 I'm using the following template to grade.  Each slot is 10 points.
 = Missing, 5=OK, 10=Wow!
 == Executive Summary ==

@@ Line 10: / Line 10: @@
 <pre style="color:red">
 Executive Summary (looks good)
-Installation Instructions (Can't find uio_pruss)
+Installation Instructions (Which SD image?)
-User Instructions (Segmentation fault)
+User Instructions (I don't see how to run the sinewave example)
 Highlights (Nice clean tone in 2nd video)
 Theory of Operation (Good overview.  I'd like to see more comment in your PRU code)
-Work Breakdown (Need to include who did what)
+Work Breakdown
 Future Work
 Conclusions
-Demo (I want to hear the clean sine before filling this in)
+Demo
-Late
+On time
-Comments:
+Comments: Great technical work on the project.  The documentation falls a bit short.
-Score:  00/100
+Score:  83/100
 </pre>

@@ Line 276: / Line 276: @@
 == Future Work ==
-For future work there are a few interesting features that we were not able to get to due to time limit and the amount of research needed to begin with. First, we found difficulty in accessing things such as the PWM and analog in ports. These could be further explored given the documents that we have dug up, and some exploration on Google. Second, we wanted to read audio from the analog input and adjust the duty_cycle of the PWM accordingly to have approximate audio output which is the next step to what we have done here. Third, we wanted to explore interrupts on the PRU, but were unable to find enough documentation to get an example working. <span style="color:red">(The 'C' code has this comment: /* Wait for event completion from PRU */.  Does it wait for the PRU?)</span>
+For future work there are a few interesting features that we were not able to get to due to time limit and the amount of research needed to begin with. First, we found difficulty in accessing things such as the PWM and analog in ports. These could be further explored given the documents that we have dug up, and some exploration on Google. Second, we wanted to read audio from the analog input and adjust the duty_cycle of the PWM accordingly to have approximate audio output which is the next step to what we have done here. Third, we wanted to explore interrupts on the PRU, but were unable to find enough documentation to get an example working.
 So, PWM, analog in, audio capabilities, and interrupts are the possible things to look into. Also, any other time critical operations can be explored further with the BeagleBone PRU because it has a delay of exactly 5ns for every instruction.

← Older revision		Revision as of 20:22, 14 November 2012
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	== Work Breakdown ==		== Work Breakdown ==
−
−	~~<span style="color:red">(DID THIS: Also include who did what.)</span>~~

	'''Milestones'''		'''Milestones'''

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 *[http://www.youtube.com/watch?v=6ytju0bkkiQ&feature=youtu.be PWM Demo].
 *[http://www.youtube.com/watch?v=aFep70xN2j4 PWM Sine Wave Approximation Example]
 == Theory of Operation ==

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 This way the number will reset to 0 as soon as it goes over the limit of memory to be read.
-To build this example, follow the same procedure as before, and wire GPIO7 (Pin 42) of P9 <span style="color:red">(DID THIS: Which header?)</span>  through a speaker to ground. The output produced will be start as a 367Hz approximation and can be changed by putting a number into the terminal (67 to 66000) and pressing enter (NOTE:Text may mess it up. So, DON'T use text!). All of the sampling for 133kHz sampling is now taken care of for any frequency wave mentioned in the previous sentence.
+To build this example, follow the same procedure as before, and wire GPIO7 (Pin 42) of P9 through a speaker to ground. The output produced will be start as a 367Hz approximation and can be changed by putting a number into the terminal (67 to 66000) and pressing enter (NOTE:Text may mess it up. So, DON'T use text!). All of the sampling for 133kHz sampling is now taken care of for any frequency wave mentioned in the previous sentence.
 == Highlights ==

← Older revision		Revision as of 20:21, 14 November 2012
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	For more information on using C to initialize the PRU visit [http://processors.wiki.ti.com/index.php/PRU_Linux_Application_Loader_API_Guide#prussdrv_map_prumem TI's PRU Linux Application Loader API Guide]		For more information on using C to initialize the PRU visit [http://processors.wiki.ti.com/index.php/PRU_Linux_Application_Loader_API_Guide#prussdrv_map_prumem TI's PRU Linux Application Loader API Guide]
−	~~<span style="color:red">Thanks for the reference. It's a big help.)</span>~~

	== Building and Running the Sin_Approximation Example ==		== Building and Running the Sin_Approximation Example ==

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 == How the C Code Works ==
 The following information can be found on TI's PRU Linux Application Loader API Guide wiki:
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 The blinker.c file is a direct port of the PRU initialization code from TI. Putting the two side by side, the only difference between the two is the name of the bin file that is used for the exec function.
-The code first initializes the PRUSS, Programmable Realtime Unit Subsystem or the entire system of two PRUs, an interrupt controller (INTC), and associated memory ([http://processors.wiki.ti.com/index.php/Programmable_Realtime_Unit_Subsystem PRUSS]),<span style="color:red">(DID THIS:What's the difference between PRUSS and PRU?)</span> by allocating memory for it using the prussdrv_init() function. It then initializes memory mapping for the PRU using the prussdrv_open() function. All of the intc functions are used for interrupt communication between the ARM and the PRU. This code is not utilized by the examples in this page.
+The code first initializes the PRUSS, Programmable Realtime Unit Subsystem or the entire system of two PRUs, an interrupt controller (INTC), and associated memory ([http://processors.wiki.ti.com/index.php/Programmable_Realtime_Unit_Subsystem PRUSS]), by allocating memory for it using the prussdrv_init() function. It then initializes memory mapping for the PRU using the prussdrv_open() function. All of the intc functions are used for interrupt communication between the ARM and the PRU. This code is not utilized by the examples in this page.
 Similar to the exec function in C, the  prussdrv_exec_program () function overlays the IRAM (Instruction RAM) portion of the PRUSS with the bin file that was created from blinker.p. The first field of prussdrv_exec_program needs a PRU number, which is either 0 or 1 depending on which PRU core is being used. In this case, PRU0 is executing blinker.bin. The second field is the path to the bin that will be put into the PRU's IRAM.

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 == How the Assembly Code Works ==
-<span style="color:red">(DID THIS:Note that this is /bin/blinker.p. DID THIS: Could you add
-some comments to the file explaining things?)</span>
 //in the overview talk about the period being 5ns

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 Now, there should be a blinker.bin file in the folder. running the blinker executabile will put the blinker.bin file on the PRU and start it running. Use the following:
   beagle$ '''./blinker'''
 == How the Assembly Code Works ==