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by timrowledge
Tue Jul 23, 2019 8:00 pm
Forum: General programming discussion
Topic: ESC Direction
Replies: 6
Views: 229

Re: ESC Direction

PeterO wrote:
Mon Jul 22, 2019 6:15 pm
Model boat ESC's are also normally reversible.
PeterO
Good point. I imagine at least some of them are water cooled as well, which could be fun for a car; an excuse for a radiator!
by timrowledge
Mon Jul 22, 2019 6:09 pm
Forum: General programming discussion
Topic: ESC Direction
Replies: 6
Views: 229

Re: ESC Direction

Very few R/C plane ESCs provide reverse, so unless OP is using a car type ESC it is unlikely to be possible to get reversing.
by timrowledge
Sat Jul 20, 2019 3:40 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: Project Digital Apocalypse Not Now

I just took advantage of the nice tweak gkriedel spotted and was pleased to see that it improved the calculation time for the big fib from circa 6secs to circa 4.8. Printing time, obviously, wasn’t changed. Your 30 second experience was not when using Squeak on an intel machine unless it is a 486 er...
by timrowledge
Fri Jul 19, 2019 5:12 am
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: A Final Fibonacci Challenge

gkreidl wrote:
Wed Jun 26, 2019 6:09 pm
Taking out the check for 0 is a good idea. My Python function now looks like this:
{snip}
Nice! That gets the calculation time for Squeak on my Pi3b+ to ~4.5sec. A clear and simple improvement from the ~6secs of the prior version.
by timrowledge
Mon Jul 15, 2019 5:37 pm
Forum: General discussion
Topic: Usefull / good programs to have on your Pi
Replies: 22
Views: 1027

Re: Usefull / good programs to have on your Pi

Botspot wrote:
Mon Jul 15, 2019 4:58 pm
And my Windows 10 transformation pack (Makes Raspbian Pixel look and feel like Windows 10)
What, deliberately? Why? Whyyyyyyyyyyyyyy!
by timrowledge
Wed Jul 10, 2019 1:15 am
Forum: General programming discussion
Topic: GUI Editor Code Challenge
Replies: 174
Views: 3567

Re: GUI Editor Code Challenge

Oh dear.i can’t offer any submission for Smalltalk - after all it’s already had a nice graphical editor with nice fonts and menus since the PARC team invented them.
And no, Heater, GNU Smalltalk not included.
by timrowledge
Mon Jul 01, 2019 8:49 pm
Forum: General discussion
Topic: I Need More Meat From My Pi
Replies: 12
Views: 606

Re: I Need More Meat From My Pi

As for #5 - write better code! Have you run profiling on it? Have you worked out where the time is going? Have you evaluated your algorithms for effectiveness? What about compiler flags? It’s rare to not be able to at least double performance over a first version. Better algorithms can provide order...
by timrowledge
Mon Jul 01, 2019 8:45 pm
Forum: General discussion
Topic: Raspberry Pi 4 usb boot?
Replies: 115
Views: 12974

Re: Raspberry Pi 4 usb boot?

hardwaremack-orginal wrote:
Mon Jul 01, 2019 6:02 pm
I'm not trying to offend anyone, just stating reality. booting and operating from a SD card is playing with fire.
Really? Are you unaware of how many millions of Pi have been working entirely adequately from SD cards for the last 6years or so?
by timrowledge
Wed Jun 19, 2019 7:35 pm
Forum: Beginners
Topic: Power on / shutdown RPI time or network
Replies: 7
Views: 339

Re: Power on / shutdown RPI time or network

There are HATs and other units that can shut a Pi down and remove power, and start it up again when a button is pressed. But I don't know of any that include a timer option. At least a couple have RTCs and micro controllers on board. The piups hat appears to be one example. SparkFun etc carry them.
by timrowledge
Wed Jun 19, 2019 7:21 pm
Forum: General discussion
Topic: How can I connect a lot of Gear flow sensor sensors to RPI?
Replies: 3
Views: 176

Re: How can I connect a lot of Gear flow sensor sensors to RPI?

Take a look at using an ESP8266 per keg, each connected to one sensor. ESPs are really cheap ($5) and are essentially very fast Arduino’s with built-in WiFi. The advantages here are that the Arduino approach handles the real-time interrupt stuff well and the WiFi means easy use of MQTT to send your ...
by timrowledge
Mon Jun 17, 2019 4:13 pm
Forum: General discussion
Topic: Generate multiple PWM signals
Replies: 5
Views: 284

Re: Generate multiple PWM signals

Consider a pwm HAT - SparkFun and AdaFruit both do good pca9685 units. Drive via i2c commands from joan’s Piggpio or even my own daemon.
by timrowledge
Sun Jun 16, 2019 8:04 pm
Forum: Scratch
Topic: Scratch 1.4 audio lock-up after raspbian update && upgrade
Replies: 2
Views: 550

Re: Scratch 1.4 audio lock-up after raspbian update && upgrade

I've racked my brain trying to work out what might be happening here but had no success. The fact that reinstalling 'fixes' it adds confusion. NuScratch does absolutely nothing strange with sounds; it uses ALSA for sound output through the normal device criving api for unix. ALSA does have a bit of ...
by timrowledge
Sat Jun 15, 2019 4:21 pm
Forum: Off topic discussion
Topic: Motors required for rc car
Replies: 2
Views: 1162

Re: Motors required for rc car

Go to rcgroups.com and look down the list of forums for the car stuff (lots of plane and boat fun as well). You’ll find people doing pretty much anything you can imagine.
by timrowledge
Thu Jun 06, 2019 6:19 pm
Forum: General programming discussion
Topic: I wants LOLcodes!
Replies: 38
Views: 1716

Re: I wants LOLcodes!

I’d say it is a pretty good mickey-take of the strained syntax that so many people consider ‘normal’ for programming.
by timrowledge
Tue Jun 04, 2019 7:59 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: A Final Fibonacci Challenge

Evidently we were talking at cross purposes for a long time as I struggled to get a result out of Smalltalk. Evidently. It happens. It's whart we invented words for though, right? I just wanted to do a simple thing. Run a program that took a single integer parameter in and put a single integer resu...
by timrowledge
Tue Jun 04, 2019 5:54 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: A Final Fibonacci Challenge

There's a place for "no talking" libraries. But I also believe there's a place for "scream your head off and bounce from the walls" libraries if that is what people want and it helps them advance. Exactly. There's plenty of grump old gits like me & Heater; kids and other less jaundiced folk have a ...
by timrowledge
Tue Jun 04, 2019 5:52 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: A Final Fibonacci Challenge

timrowledge, Wait, hang on - how does using any sort of approximation via a floating point number produce a correct answer to an integer problem? Surely that can't be right? Magic isn't it! Damn right. I'm not a Numerics guy by any stretch but that really make my head spin. I'll see what my mathema...
by timrowledge
Tue Jun 04, 2019 12:58 am
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: A Final Fibonacci Challenge

It takes 32 seconds in Squeak Smalltalk on my old PC. Over five hours in GNU Smalltalk! As we've mentioned, the latest version (which you can get simply by updating from within the system you already have) is a bit faster and actually does the calculation in 6.6 secs (not 11) on my Pi3 or 0.9s on m...
by timrowledge
Tue Jun 04, 2019 12:41 am
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: A Final Fibonacci Challenge

timrowledge, Javascript was created by Brendan Eich. He wanted to make Self for the browser but Netscape insisted he make it look more like Java. That is why JS has all those Scheme like features: first class functions, closures, etc. And let's remember that Self came out of the Smalltalk community...
by timrowledge
Tue Jun 04, 2019 12:38 am
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: A Final Fibonacci Challenge

danjperron wrote:
Mon Jun 03, 2019 8:21 pm
Wait, hang on - how does using any sort of approximation via a floating point number produce a correct answer to an integer problem? Surely that can't be right?
by timrowledge
Tue Jun 04, 2019 12:27 am
Forum: Scratch
Topic: Scratch 1.4 sound problem.
Replies: 16
Views: 3516

Re: Scratch 1.4 sound problem.

OK, yes I hear the reverb for the file sounds, but it all sounds pretty ok to me other than that. The last two are clear indications that the 'timidity' midi stuff isn't installed; if it were they'd actually be the standard numbered MIDI noises nad changing the drum or instrument would be very heara...
by timrowledge
Mon Jun 03, 2019 8:55 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: A Final Fibonacci Challenge

danjperron wrote:
Mon Jun 03, 2019 8:21 pm
I will check how long it takes the pi to calculate fibo(4784969). Hum a week, a month?
Evidently you hadn’t noticed that people have been posting the answer(s) o that question for a while now. As an example, it takes around 11secs in Smalltalk. A bit less than a month 😁
by timrowledge
Mon Jun 03, 2019 5:18 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: A Final Fibonacci Challenge

Given the expertise in technology at MIT, one can't help but wonder whether the requirement to store high scores in the cloud was by design and the need to earn a Scratcher badge before doing so intentional. Luckily, the default Scratch on the Raspberry Pi, called nuScratch, is an update to the ori...
by timrowledge
Mon Jun 03, 2019 4:56 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: A Final Fibonacci Challenge

Smalltalk is relatively slow at accessing arrays because every access is bounds-checked. This makes some of the favoured trivial benchmarks seem very slow - but it does mean we suffer rather fewer issues with junk getting poked into memory in places where it isn't good. Which is more important? Dep...
by timrowledge
Mon Jun 03, 2019 12:05 am
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 760
Views: 29242

Re: A Final Fibonacci Challenge

Then you have a language using a fundamental design that makes it no so good for this particular problem. If this kind of problem is important, you'd need to change something deep in your system. If it isn't, don't worry, accept that decisions have consequences and move on to enjoy whatever benefits...

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