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Larry_Adlard
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Joined: Tue May 29, 2012 8:07 pm
Location: Bradford, West Yorkshire, UK

24 hours on

Tue May 29, 2012 9:25 pm

I'm writing this because this is a new machine, a new processor, a new environment. I'm not an expert in Linux or Python but I started this journey with a 6502 processor with 2 Kilobytes of memory 38 years ago, so in the intervening years I've learned how to get to grips with things.

The Pi was delivered around lunch time yesterday. My first problem was to find a power supply because I don't have a modern style phone with a micro-USB charger. Unless you choose a cell phone charger, your options are VERY limited. I purchased a car cigar lighter charger from Maplin.
CAT No A47KA - 7.99-UKL. The adapter reduces the voltage to 5v. I have an emergency battery box for starting cars and it has a cigar lighter socket on the side. That can deliver enough power for a few dozen Pi.

I'm seeing complaints about speed on the Pi. This isn't all down to the speed of the processor. It doesn't matter how fast the processor / operating system works if the storage access is slow. SD Cards come in various speeds. This is indicated by a symbol C with a number contained within the C. E.g. C4, C6, C10 etc. If it hasn't got a C rating it's probably very slow to access and write. I've compared a C4 and a C10 card and the difference is noticeable. The C10 is about twice as fast. They're not expensive. Systemax ( Misco in the U.K ) sell an Itegral 16Gb Class 10 SD Card for 9.60-UKL and there is an 8Gb version for less. I don't have a preference for brands so I should mention that Kingston sell even faster?? /bigger cards. My C4 is a TDK MicroSD in a full size SD adapter.

Whoever prepared the release didn't pay a lot of attention to detail. I'm not familiar with games or educational software so 'Scratch' and 'Squeak' are a total mystery to me. I can't find an example program to run or a 'RUN' button. There is a 'Help' tab but no help. I can't see why this was included in the distribution; It's just very discouraging for beginners.
BTW I've seen complaints about getting sound using the HDMI interface. I can't get a peep out of the audio connection either and the picture quality is the worst I've seen in 30 years. In fairness it is a very old CRT TV.

In order to lift the tone I was going to attach a few simple PYTHON programs just to provide a bit of encouragement. I prefer 'IDLE' as an editor but 'GEANY' is ok. Just to make sure I tested them out in 'GEANY'. 'GEANY' can't produce output because like other editors it looks for a program called 'XTERM' and that isn't included in the distribution. Instead there is 'BASH' and 'DASH' and like these, 'GEANY' needs to look for 'LXTERMINAL.' All this proves is that no one checked whether any of the software worked before it was released. It would be better to have no software instead of wasting everyone's time. Get Professional!! This is a distribution for (among others) children - not by children.

If I've got a fix for 'GEANY' by tomorrow then we can start some simple 'PYTHON'.

It's a poor start but no worse than it was 38 years ago, when there were very few people you could ask. I am hoping my biting critism will be a spur to a better distribution 'Next time.' It's not the end of the world - but someone needs their butt kicked.
:D

jamesh
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Re: 24 hours on

Tue May 29, 2012 10:18 pm

There is a new release being developed which should be a lots friendlier.

Meanwhile, keep at it, you never stop learning! Although, from some of the comments posted here, starting learning seems to be too much like hard work for some people.
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max1zzz
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Re: 24 hours on

Tue May 29, 2012 10:34 pm

too lift the tone a bit, i don't actually think a slightly flawed distribution is always a bad thing, it teaches you to do bug finding (maybe it's just me, but i kinda enjoy the 4 hours of swearing trying to get it to work more than using it when it is working) However, i do agree that for the educational launch it needs to be more polished, as most people in my year would go "Meh, it doesn't work, cba..."

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rurwin
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Re: 24 hours on

Tue May 29, 2012 10:47 pm

In the foundation's defence, they weren't expecting the Debian release to be what we were using, it was supposed to be the Fedora-based one, but it had too many bugs.

As something to play with, try this. Copy it into a file called "quest.py" and run it in an lxterminal with "python quest.py"

Bigwol
Posts: 22
Joined: Thu Feb 09, 2012 12:22 pm

Re: 24 hours on

Wed May 30, 2012 12:24 am

rurwin

Thanks for that,

My pi's in RS hospital, having shown few signs of life on arrival, but your quest py prog was fun, and brought back Commodore PET / Sirius 1 (Pre IBM PC) memories from the dim and distant!

More power to your elbow

Cheers

Dave

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Larry_Adlard
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Location: Bradford, West Yorkshire, UK

Re: 24 hours on

Wed May 30, 2012 11:15 am

Well, we're another 24 hours on and here is the fix for Geany. As described yesterday it expects to find xterm and what you have is lxterminal. Same animal, different name. You can tell Geany about this. Fire up Geany and note the tool bars across the top. You need to click on Edit and select Preferences from the Dropdown box. This brings up a dialogue box with a menu down the left hand side 'General, Interface ..... Tools'. Select 'Tools' and another dialogue box pops up. Now you can see the problem in the top box. It looks for 'xterm'. Click on this box to edit it. Change it to 'lxterminal' (all lowercase). That's an L lowercase beginning.

That should be it, but this is like history - "Just one damned thing after another." The dialogue box is much deeper than your screen and you can't get to the apply/accept/change button which is located about 300mm or 1 foot below the bottom of your screen. You can resize the dialogue box but only in the horizontal and not the vertical and there's no way to induce a vertical slider bar down the right hand side - Scuppered!!!

Not quite. Mice weren't always hot pluggable or reliable and all the dialogue boxes I've ever seen respond to the TAB key. There should be a flashing vertical text cursor at the end on the word lxterminal|. If it has disappeared use the mouse to click on the input box until you can see it. Now press the TAB key 3 times and the cursor will now appear in the box below in 'sensible browser'. We're not going to alter that so press the TAB key another 3 times and you are now in the next box 'grep', and another 3 TABS takes you to 'context'.

From now on you need to count carefully because you are working blind. Press the TAB key 3 times and you are on the apply/accept/change button even though you can't see it. Press the <return> key.That changes the setting. You now need to press the TAB key twice to get from Apply to OK. Press <return> again and the dialogue box should disappear.

To save gnashing of teeth later it's worth checking that the change has taken effect so click on Edit/Preferences/Tools and make sure that the top box reads 'lxterminal'. If it does then you can click on the X in the top right corner to close the dialogue box and Geany should work from now on. If it doesn't show 'lxterminal' work on it until it does.

Onwards and upwards. The first program calculates factorials. If you don't already know I'll explain factorials by example. Factorial of 3, written in math as 3! is equal to 3 x 2 x 1 = 6.
Factorial 6 = 6! = 6 x 5 x 4 x 3 x 2 x 1 = 720. Factorial 10! = 10 x 9 x 8 ..... x 1. Get the picture? Very interesting you might think, just like school math. You learn it in the abstract and never find out what it's for. Factorials are used to calculate Permutations and Combinations and through that Probabilities, handy if you are visiting a casino. Probability theory is also an essential part of modern artificial intelligence so this is just one little brick in the vast wall that leads to Google's self driving cars or unmanned aerial drones. Try numbers between 3 and 100. Higher than that and be prepared for a wait. The total builds up quickly. Try a really large number and Python will continue calculating until it runs out of memory or you come to a natural end, which ever happens first.

When you have downloaded the program, use 'File', 'Open' in Geany to load the program. There is a graphical tool-bar below 'File','Edit' etc. Click on the Gears symbol at the right hand side to run it. It may not be big and fancy but it is small and working, and if you once wrote a program in Fortran, Basic or 'C', years ago, you'll recognise what's going on.

Finally, thanks to the people who commented on the original post. You made some valid points.

PS. Here we go again. I'm not allowed to upload a file with the extension .py or .txt so the listing is given below:- You can practise your typing or cut and paste. The indenting in the 'for loop' is essential.

PPS. Yes I do realise why I'm not allowed to upload a program. Pity though.

Code: Select all

# A hash is used to make a comment. Mostly ignored by program
# I wish it was // like 'C' and Java but it isn't, so tough

product = 1                                       # declare a starting value
number  = input (" Enter number 1-99 ")           # NB. no error checking

for i in range (number):                          # Python counts from 0 
	product = product * (i+1) 
	print (i+1), product                           # print running total

print "" 
print "Factorial for ",number,"is ", product


backsmith
Posts: 5
Joined: Sun Jun 03, 2012 3:50 pm

Re: 24 hours on

Sun Jun 03, 2012 7:23 pm

I'm writing this because this is a new machine, a new processor, a new environment. I'm not an expert in Linux or Python but I started this journey with a 6502 processor with 2 Kilobytes of memory 38 years ago, so in the intervening years I've learned how to get to grips with things.
Hey Me too!!!!

I would like to add a bit of feedback too.

I have spent the day with my new Pi. Mostly trying to get Scratch working as I saw an artical about it in the MagPi and thought it would be a cool way to get the kids into it. I am quite computer savy but newish to linux. I have an ubunto box I play about with some times.

Please dont read this as a rant. I am sure that loads of people have done loads of stuff for free in time they could not really spare.

My inital comments are about the information that is availible. I began on the element14 site with the getting started videos. These are based on a virtual machine. I spent a fair amount of time installing packages that are actually already there. Now nothing is wasted, and i now know what a apt-get and a sudo do, and what a terminal and GUI package manager are so thats ok. But I think the front page of the web site offering to get people started should be more clearly labled and relate to the current OS release for the machine - debian.

I spent a fair bit of time on the forum. This is in a mixup too. Some threads started by helpful folk to be idiot guides have been hijacked by the linux inteligensia with agruments over the various merits and correct proceedures. The ones about scratch for example has two teams one saying its great and one saying its a waste of time but no one saying how to get the darn thing to install. For me at the moment a quick guide practical guide on how to do stuff and a bit of a note on how it works would be great.

I know its early days but I really think these two sides of the forum need to be carefully seperated and moderated.

On a positive note Python works fine and I worked out for myself about the terminal issue.

I dont really want windows emulators, games or media stuff, all I want is a cheap machine that the kids can learn to program. We have some cool LEGO that is waiting to be controlled too. I remember fondly the BBC micro project and would love to see a similar experience all over again.


Cheers John

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