[FOSS-GPS] RTKLib MIPS requirements?

Thu May 3 02:04:22 EDT 2012

Dear Danny,

Sorry, I assumed that you read this paper
http://gpspp.sakura.ne.jp/paper2005/isgps_2009_rtklib_revA.pdf
before posting.
There you may find more details about RTKLIB computational load at 10Hz.

Best regards,
Michele

On 02/05/2012 23:08, Danny Miller wrote:
> Well correct me if I'm wrong but this seems to come down to how many 
> flops it can do, the moving of variables and such is probably a 
> minority of the processing.  That's why I wanna focus on the flops 
> requirement.
>
> How much resources does RTKLib consume on Beaglebone?  Because BB 
> being faster and capable of RTKLib still doesn't establish the 
> processing requirements.  Is it running at 60% core utilization or 5%?
>
> I did run RTKLib on my i7 Q 740 1.73GHz laptop and the utilization was 
> basically nil.  I really couldn't determine anything from that, the 
> usage figure was too low to give a meaningful number, not when the 
> capabilities are at least 100x greater.  I mean if the usage was 10% 
> on that i7 I could pretty well dismiss it working on a Cortex M4.  
> IIRC it was like a single-digit or fractional % though and the OS can 
> consume considerable resources managing the busses and displaying the 
> maps and interfaces so that doesn't mean much.
>
> Raspberry PI would be nice, but I can't get ahold of one, much less 
> will it be readily available at this time for widespread consumption 
> if the application worked.  I'm still uncertain if widespread, 
> long-term, low-price distribution is gonna happen or just turn out to 
> be vaporware.  STM32F4, anybody CAN order one or a thousand and get 
> them for $15 or better right now.  Still got high hopes of course.  
> Raspberry PI also wasn't designed with a lot of low-level hardware 
> interfacing so it'd still require a daughterboard like the STM32F4 to 
> interface with a rover's motors and sensors and all.
>
> Danny
>
> On 5/2/2012 3:40 PM, Michele Bavaro wrote:
>> Hi Danny,
>>
>> I strongly doubt that a STM32F4 will be able to run RTKLIB.
>> It's true that it runs on a beaglebone, but Cortex-A8 has around 
>> 2MIPS/MHz and runs at frequencies close to 1GHz,
>> whereas a Cortex-M4 has 1.25MIPS/MHz and runs at frequencies up to 
>> 150MHz: there is almost one order of magnitude.
>> In addition since the structure of rtkrcv is quite strongly coupled 
>> with a Linux OS,
>> there will be a lot of effort required to port it to a lighter RTOS, 
>> let go to bare metal code.
>>
>> But I don't want to discourage you.. if you think it's doable go for 
>> it :)
>>
>> Best regards,
>> Michele
>>
>> On 02/05/2012 00:15, Danny Miller wrote:
>>> STM32F4 "demo board" uses an Arm Cortex m4.  32 bit, 210 DMIPs and a 
>>> single-precision hardware FPU.  I'm slightly unclear on the memory 
>>> space it has on this specific board but it should be 192KB SRAM and 
>>> 1MB flash.  That's my porting plan.
>>>
>>> If it WORKS, it'll be a great system, these boards are absurdly 
>>> cheap.  It is several more orders of magnitude of capability than 
>>> these 8bit PICs and such, but I don't understand the scale of the 
>>> flops requirement of RTKLib.  I know it's somewhere between "much 
>>> more than any 8-bit controller could ever do" and "won't even make 
>>> Intel i7 break into a sweat".   And those are wildly different 
>>> magnitudes.  I don't know exactly where RTKLib 10Hz would be between 
>>> those.
>>>
>>> And it's be running RTKLib and just some minor application 
>>> (navigation and monitoring) code which will not be 
>>> processor-intensive, and it's not using Linux or an RTOS.  So 
>>> there's not a significant overheat for other tasks and the 
>>> overhead's timing can be managed predictably and accurately.  Pretty 
>>> much the core can either do it or it can't.
>>>
>>> Danny
>>>
>>> On 5/1/2012 4:43 PM, julio menezes wrote:
>>>> Hi Danny,
>>>>
>>>>
>>>>> I have a core with a hardware FPU, but it's only capable of
>>>>> doing Single floats, not Double.  It is going to break
>>>>> things to implement the specified Double calcs with Single
>>>>> precision?  I would assume so, but it's worth asking.
>>>>>
>>>> The RTKLIB author T.Takasu and A.Yasuda have  ported RTKLIB to a 
>>>> BeagleBoard which has an ARM Cortex-A8- with 1 GHz and floating 
>>>> point, I do not know if double or single precision.
>>>>
>>>> I plan to move in this direction also, may be using a hardware less 
>>>> powerful but cheaper.
>>>> Raspberry Pi
>>>> http://www.raspberrypi.org/faqs
>>>> The SoC is a Broadcom BCM2835.
>>>> This contains an ARM1176JZFS, with floating point, running at 
>>>> 700Mhz, and a Videocore 4 GPU.
>>>>
>>>> I am waiting, anxiously,  the RTKLIB 2.4.2 version with RTCM-104 
>>>> phase messages encoder to built a local base station as where I 
>>>> live there are no near NTRIP network ( less than 10km ).
>>>>
>>>> good luck,
>>>>
>>>> julio menezes
>>>>
>>>>
>>>> _______________________________________________
>>>> This message is sent to you from FOSS-GPS at lists.osgeo.org mailing 
>>>> list.
>>>> Visit http://lists.osgeo.org/mailman/listinfo/foss-gps to manage 
>>>> your subscription
>>>> For more information, check http://wiki.osgeo.org/wiki/FOSS-GPS
>>>>
>>>
>>> _______________________________________________
>>> This message is sent to you from FOSS-GPS at lists.osgeo.org mailing list.
>>> Visit http://lists.osgeo.org/mailman/listinfo/foss-gps to manage 
>>> your subscription
>>> For more information, check http://wiki.osgeo.org/wiki/FOSS-GPS
>>
>> _______________________________________________
>> This message is sent to you from FOSS-GPS at lists.osgeo.org mailing list.
>> Visit http://lists.osgeo.org/mailman/listinfo/foss-gps to manage your 
>> subscription
>> For more information, check http://wiki.osgeo.org/wiki/FOSS-GPS
>>
>
> _______________________________________________
> This message is sent to you from FOSS-GPS at lists.osgeo.org mailing list.
> Visit http://lists.osgeo.org/mailman/listinfo/foss-gps to manage your 
> subscription
> For more information, check http://wiki.osgeo.org/wiki/FOSS-GPS