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by ag123
Sun Apr 23, 2017 7:06 am
Forum: STM32F4 Boards
Topic: FPU on F407 - how to
Replies: 93
Views: 965

Re: FPU on F407 - how to

i found that the particular define __ARM_PCS_VFP only shows up if -mthumb -mcpu=cortex-m4 -mfloat-abi=hard -mfpu=fpv4-sp-d16 is defined apparently this particular define won't show up with -mthumb -mcpu=cortex-m4 -mfloat-abi=softfp -mfpu=fpv4-sp-d16 (i.e. software floats) or if it is simply left out...
by ag123
Sun Apr 23, 2017 6:05 am
Forum: General discussion
Topic: Dhrystone and Whetstone Benchmarks for STM32F103
Replies: 150
Views: 7303

Re: Dhrystone and Whetstone Benchmarks for STM32F103

@victor the results u've shown are for double precision, for single precision edit whetstone.cpp /* default is double precision, define this for single precision */ #undef SINGLE_PRECISION ^^note that this is #undef, change that to /* default is double precision, define this for single precision */ ...
by ag123
Fri Apr 21, 2017 8:51 pm
Forum: STM32F4 Boards
Topic: FPU on F407 - how to
Replies: 93
Views: 965

Re: FPU on F407 - how to

of course for the *hard core* probably can do highly optimised double precision floating point using hard core tuned assembly making sure the loops are unrolled and overclock that to 240mhz or higher and let the ART accelerator drive it there :lol:
by ag123
Fri Apr 21, 2017 8:30 pm
Forum: STM32F4 Boards
Topic: FPU on F407 - how to
Replies: 93
Views: 965

Re: FPU on F407 - how to

i'd think it may matter if we do some iterative root finding stuff, using floats may lead to the algorithms going in loops and never converging as errors keep cumulating with each iteration :lol: but i'd guess the f4 'platform' is a niche of sorts, at least the performance is decent/good for these t...
by ag123
Fri Apr 21, 2017 6:46 pm
Forum: IDE's
Topic: IDE with Eclipse with Jantje's plugin
Replies: 117
Views: 3381

Re: IDE with Eclipse with Jantje's plugin

i'd think it is a good idea to work in eclipse either with the addition of jantje's plugin or perhaps system workbench or in eclipse + gnu arm eclipse i think each environment has their plus and minus and in fact eclipse would support arduino directly in the cdt in neon and oxygen (currently with a ...
by ag123
Fri Apr 21, 2017 6:02 pm
Forum: STM32F4 Boards
Topic: FPU on F407 - how to
Replies: 93
Views: 965

Re: FPU on F407 - how to

perhaps at some point in time, we may have an f4 solving the travelling sales man problem https://en.wikipedia.org/wiki/Travelling_salesman_problem in real time and win the races :lol: http://wiki.evilmadscientist.com/TSP_art https://www.google.com.sg/search?q=tsp+art&tbm=isch&tbo=u&sour...
by ag123
Fri Apr 21, 2017 5:30 pm
Forum: STM32F4 Boards
Topic: FPU on F407 - how to
Replies: 93
Views: 965

Re: FPU on F407 - how to

stm32 f1 is the benchmark :D
for those that are slower too bad :P :lol:
by ag123
Fri Apr 21, 2017 5:28 pm
Forum: STM32F4 Boards
Topic: FPU on F407 - how to
Replies: 93
Views: 965

Re: FPU on F407 - how to

Unfortunately, calling it in init() doesn't guarantee that it will be called before any of the _pre_init constructors. hi rick, my thoughts are that calling it within init() is adequate for the purpose in fact i'm somewhat worried if enabling the fpu may caused unexpected behaviours for sketches th...
by ag123
Fri Apr 21, 2017 4:44 pm
Forum: STM32F4 Boards
Topic: FPU on F407 - how to
Replies: 93
Views: 965

Re: FPU on F407 - how to

actually it just show that stm32f4 + ART accelerator + fpu + -fsingle-precision-constant + float specific math lib function + -O2 optimization + overclock is real rocket fuel (and that's not yet adding hardware fpu compiled math lib functions) :lol: but to leave something for the stm32 f1 users i'd ...
by ag123
Fri Apr 21, 2017 10:24 am
Forum: General discussion
Topic: Serial.write problem
Replies: 18
Views: 216

Re: Serial.write problem

try with Serial.write("0123456789", 10); at the code location, commenting the original codes you could make a longer string which is similar to the size that you need. this may help to troubleshoot it. if necessary you may like to trouble shoot with a 'hard coded' byte pattern resembling y...

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