Can you help me, I've installed UHD but Uhd_find_devices and Uhd_probe
nothing :(
Please help

On Fri, Aug 7, 2015 at 4:18 AM, William Hermans <[email protected]> wrote:

> *The Prus are pretty powerfull for driving the io pins and their
>> deterministic nature are very useful. But it was a little hard for me to
>> learn each topic. Gpio access, interrupts, memory mapping and the
>> scratchpad.*
>> *In the process of learning, I have written a small library, I called it
>> libpru. It is composed of pru assembly include file and c++ counterpart for
>> the arm processor. Maybe it can be useful to other people, I do not know
>> git very well but maybe I will  uploaded it somewhere.*
>>
>
> I do not know git very well either. It's something I've been putting off
> for a while( learning about ), but eventually I think all software
> developers need to learn, and use git.
>
> It's been keeping me from sharing my current code for the project I'm
> working on, but it's currently a mess anyway heh ! I have not even updated
> my blog in a couple years . . . which has been on my mind too. Lots of
> energy to invest in such thing though - When you would rather be doing
> something else like learning some new software / hardware aspect, etc.
>
> I would not mind seeing your work sometime, but could not say when I would
> get the time to look. If a blog post or similar I probably read a couple a
> day so would not be a problem - But reading through, and understanding
> someones code . . . is another story. Especially since my ASM is very
> rusty, and my ARM ASM knowledge is non existent.
>
> On Thu, Aug 6, 2015 at 2:10 PM, Carlos Novaes <[email protected]> wrote:
>
>>
>> Interesting idea, if only pwm. I did not write it before, but pru1 will
>> also read five incremental encoders and report the positions back to the
>> arm side. So I have some free time on pru1 to manage pru0 and arm
>> communication, but can't dedicate it exclusively for that. Also, there are
>> two digital outputs and two digital inputs (on off).
>>
>> Le jeudi 6 août 2015 18:04:11 UTC-3, Carlos Novaes a écrit :
>>>
>>> The Prus are pretty powerfull for driving the io pins and their
>>> deterministic nature are very useful. But it was a little hard for me to
>>> learn each topic. Gpio access, interrupts, memory mapping and the
>>> scratchpad.
>>> In the process of learning, I have written a small library, I called it
>>> libpru. It is composed of pru assembly include file and c++ counterpart for
>>> the arm processor. Maybe it can be useful to other people, I do not know
>>> git very well but maybe I will  uploaded it somewhere.
>>>
>>>
>>> Le mardi 4 août 2015 18:30:12 UTC-3, William Hermans a écrit :
>>>>
>>>> Hello Carlos,
>>>>
>>>> Thanks for sharing. Personally I'm always interested in what others are
>>>> doing, and like to see "progress reports". Not that anyone has to report
>>>> anything to me personally, but I still like reading about what others are
>>>> doing.
>>>>
>>>> I expect some day in the future I will be investing some time getting
>>>> to know the PRU's as well. But as a hobby, I have the luxury of doing so,
>>>> when I get around to it ;)  Anyway, I've always found the PRUs interesting
>>>> . . .maybe that will be my next "pet" project ?
>>>>
>>>> On Tue, Aug 4, 2015 at 12:03 PM, Carlos Novaes <[email protected]>
>>>> wrote:
>>>>
>>>>> Hello everyone. This is just an update.
>>>>>
>>>>> I tried the direct connection mode but it is more suitable for syncing
>>>>> the two PRUs. Anyway,  my previous approach will work. As Lenny said:
>>>>> In case that one PRU reads from the scratchpad and in the same cycle
>>>>> the other PRU writes to it, I am pretty sure that there will be no
>>>>> conflicts. It is the standard behaviour when you program sequential logic
>>>>> with a hardware description language. However, the read operation will
>>>>> yield the "old" data from the scratchpad, that is the ones from before the
>>>>> write operation.
>>>>>
>>>>> That's exactly what happens. no extra delays or any type of conflict.
>>>>>
>>>>> Thank you Lenny, and everyone else.
>>>>>
>>>>> Carlos Novaes
>>>>>
>>>>>
>>>>> PS: If it is of interest to someone here comes my test experiment:
>>>>> I had PRU0 and PRU1 with cycle register enabled and counting clock
>>>>> cycles. Over each iteration on a total of twenty, the cycle register was
>>>>> read and stored into one register from r0 to r19. This on both PRUs
>>>>> On PRU0 I also read r23 from scratch pad and the store its lower word
>>>>> (r23.w0) into the upper word (rx.w2) of one of r0 to r19. Total cycle
>>>>> counting is 6 for each iteration.
>>>>> On PRU1 I store the lower word of r23 into the upper word of one of r0
>>>>> to r19 (according to the iteration) and also increment r23 and store it on
>>>>> the scratchpad. Total cycle counting is 7 for each iteration.
>>>>> Then, on both PRUs, write r0 to r19 into the shared ram and signal the
>>>>> ARM.
>>>>> On the ARM side, wait for signals from PRU0 and PRU1, read the shared
>>>>> ram (data from both PRUs), calculate the cycle offset of each iteration 
>>>>> and
>>>>> print the results. There are no stall on any PRU, all iteractions takes
>>>>> exactly 6 cycles on PRU0 and 7 cycles on PRU1. At each 7 iteractions, PRU0
>>>>> will repeat the previous value of r23.
>>>>> Here comes the output from console:
>>>>>
>>>>> :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
>>>>>                      PRU0                            ::::::
>>>>>           PRU1                            :
>>>>>     Value     :     Cycle     :     Cycle Offset     ::::::    Value
>>>>>   :     Cycle     :     Cycle Offset     :
>>>>>             1 :          58960:  ------------------  ::::::
>>>>>  1 :             16:  ------------------  :
>>>>>             2 :          58966:                     6::::::
>>>>>  2 :             23:                     7:
>>>>>             3 :          58972:                     6::::::
>>>>>  3 :             30:                     7:
>>>>>             4 :          58978:                     6::::::
>>>>>  4 :             37:                     7:
>>>>>             5 :          58984:                     6::::::
>>>>>  5 :             44:                     7:
>>>>>             6 :          58990:                     6::::::
>>>>>  6 :             51:                     7:
>>>>>             7 :          58996:                     6::::::
>>>>>  7 :             58:                     7:
>>>>>             7 :          59002:                     6::::::
>>>>>  8 :             65:                     7:
>>>>>             8 :          59008:                     6::::::
>>>>>  9 :             72:                     7:
>>>>>             9 :          59014:                     6::::::
>>>>> 10 :             79:                     7:
>>>>>            10 :          59020:                     6::::::
>>>>> 11 :             86:                     7:
>>>>>            11 :          59026:                     6::::::
>>>>> 12 :             93:                     7:
>>>>>            12 :          59032:                     6::::::
>>>>> 13 :            100:                     7:
>>>>>            13 :          59038:                     6::::::
>>>>> 14 :            107:                     7:
>>>>>            13 :          59044:                     6::::::
>>>>> 15 :            114:                     7:
>>>>>            14 :          59050:                     6::::::
>>>>> 16 :            121:                     7:
>>>>>            15 :          59056:                     6::::::
>>>>> 17 :            128:                     7:
>>>>>            16 :          59062:                     6::::::
>>>>> 18 :            135:                     7:
>>>>>            17 :          59068:                     6::::::
>>>>> 19 :            142:                     7:
>>>>>            18 :          59074:                     6::::::
>>>>> 20 :            149:                     7
>>>>>
>>>>>
>>>>>
>>>>> Le dimanche 2 août 2015 21:21:10 UTC-3, Carlos Novaes a écrit :
>>>>>
>>>>>> Hi Lenny. Sorry for the delay.
>>>>>> Usually, PRU1 will have new data received from the ARM before PRU0
>>>>>> complete one PWM sample, this is the key point. If the ARM sporadically
>>>>>> could not deliver a control action in time, the PWM should just repeat 
>>>>>> the
>>>>>> last values, so reading the old data is desirable.
>>>>>> I really did not think in use direct PRU transfer and I don´t know
>>>>>> why. Maybe because at my first readings this seemed unsafe. I will give 
>>>>>> it
>>>>>> a try, thank you for the idea.
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> Le dimanche 2 août 2015 12:04:04 UTC-3, Lenny a écrit :
>>>>>>>
>>>>>>> Oh sorry, I didn't see your PS ;)
>>>>>>>
>>>>>>> In case that one PRU reads from the scratchpad and in the same cycle
>>>>>>> the other PRU writes to it, I am pretty sure that there will be no
>>>>>>> conflicts. It is the standard behaviour when you program sequential 
>>>>>>> logic
>>>>>>> with a hardware description language. However, the read operation will
>>>>>>> yield the "old" data from the scratchpad, that is the ones from before 
>>>>>>> the
>>>>>>> write operation.
>>>>>>>
>>>>>>> But as you have lots of time to waste on one PRU, it might be a
>>>>>>> better idea to use direct PRU transfer (XIN/XOUT with device 14), 
>>>>>>> without
>>>>>>> the scratchpad in between. Lets say your PRU0 (the time-critical one)
>>>>>>> executes N instructions per loop. Then just let PRU1 make an update of 
>>>>>>> the
>>>>>>> important registers every M cycles (with M<N) so that data for PRU0 will
>>>>>>> always be fresh and PRU0 will never have to wait for PRU1. The 
>>>>>>> advantage is
>>>>>>> that your PWM will run perfectly deterministic, that is there will 
>>>>>>> never be
>>>>>>> any irregularities in the output signal due to the interrupt. The data 
>>>>>>> will
>>>>>>> be updated every PWM cycle, and all this only costs you one instruction 
>>>>>>> per
>>>>>>> PWM loop cycle.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Sunday, August 2, 2015 at 4:39:21 PM UTC+2, Lenny wrote:
>>>>>>>>
>>>>>>>> Hi Carlos,
>>>>>>>>
>>>>>>>> have you looked at the PruReferenceGuide section 5.2.4.2 (p.34-35)?
>>>>>>>> Let me copy paste here:
>>>>>>>>
>>>>>>>>
>>>>>>>> A collision occurs when two XOUT commands simultaneously access the
>>>>>>>> same asset or device ID.
>>>>>>>> Table 20 shows the priority assigned to each operation when a
>>>>>>>> collision occurs. In direct connect mode
>>>>>>>> (device ID 14), any PRU transaction will be terminated if the stall
>>>>>>>> is greater than 1024 cycles. This will
>>>>>>>> generate the event pr<1/0>_xfr_timeout that is connected to INTC.
>>>>>>>>
>>>>>>>> Table 20. Scratch Pad XFR Collision Conditions
>>>>>>>>
>>>>>>>> Operation Collision Handling
>>>>>>>> PRU<n> XOUT (→) bank[j]
>>>>>>>> If both PRU cores access the same bank simultaneously, PRU0
>>>>>>>> is given priority. PRU1 will temporarily stall until the PRU0
>>>>>>>> operation completes.
>>>>>>>>
>>>>>>>> PRU<n> XOUT (→) PRU<m> If PRU<n>
>>>>>>>> executes XOUT before PRU<m> executes XIN, then
>>>>>>>> PRU<n> will stall until either PRU<m> executes XIN or the stall
>>>>>>>> is greater than 1024 cycles.
>>>>>>>>
>>>>>>>> PRU<n> XIN (←) PRU<m> If PRU<n> executes XIN before PRU<m> executes
>>>>>>>> XOUT, then
>>>>>>>> PRU<n> will stall until either PRU<m> executes XIN or the stall
>>>>>>>> is greater than 1024 cycles.
>>>>>>>>
>>>>>>>>
>>>>>>>> I used the direct XOUT / XIN with device ID=14 to synchronize the
>>>>>>>> two PRU's. There were no unexpected problems, everything like 
>>>>>>>> described in
>>>>>>>> the manual.
>>>>>>>>
>>>>>>>> Let me know if this wasnt your problem. Bests, Lenny
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>> For more options, visit http://beagleboard.org/discuss
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>>>>
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