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by jahboater
Sat Aug 06, 2016 4:03 pm
Forum: Beginners
Topic: Some beginner questions :)
Replies: 4
Views: 921

Re: Some beginner questions :)

By the way, the "Evo" model of SD Cards by Samsung (64GB) should work without problems according to you ? That's a good SD card. Do you have a specific need for 64GB ? Price wise, 16 - 32 is the sweet spot. If you are just experimenting with the GPIO then you will never fill a 16GB card. Linux itse...
by jahboater
Fri Aug 05, 2016 6:43 pm
Forum: General discussion
Topic: python3.4.2
Replies: 9
Views: 1822

Re: python3.4.2

Yes, slightly different for python3, but the message implied some other problem.

Code: Select all

pi@raspberrypi:~ $ python3
Python 3.4.2 (default, Oct 19 2014, 13:31:11) 
[GCC 4.9.1] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> print("hello world")
hello world
>>> 
by jahboater
Fri Aug 05, 2016 6:30 pm
Forum: General discussion
Topic: python3.4.2
Replies: 9
Views: 1822

Re: python3.4.2

All the data I perused use the print ¨Hello World¨ in the above format as an example. So what am I missing? Works for me: pi@raspberrypi:~ $ python Python 2.7.9 (default, Mar 8 2015, 00:52:26) [GCC 4.9.2] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> print "he...
by jahboater
Fri Aug 05, 2016 6:22 pm
Forum: General discussion
Topic: SD Cards Blowing
Replies: 71
Views: 11488

Re: SD Cards Blowing

My cards last for years.

As Dougie says, buy decent quality cards (genuine Samsung Evo for example) and look after them. If your cards are not fake, and they only last for a few days, then you are doing something terribly wrong.

There is a lot of information about how to reduce writes to the card.
by jahboater
Fri Aug 05, 2016 9:03 am
Forum: Bare metal, Assembly language
Topic: what's the meaning of this warning ?
Replies: 6
Views: 2160

Re: what's the meaning of this warning ?

new_guy wrote:
Warning: if writeback register is in list, it must be the lowest reg in the list
Warning: writeback of base register when in register list is UNPREDICTABLE

what does these actually mean ? thank you .
Have you got something like this?

Code: Select all

ldm r1!,{r0-r3}
by jahboater
Fri Aug 05, 2016 8:54 am
Forum: Beginners
Topic: setting up
Replies: 9
Views: 1678

Re: setting up

Nothing happens. The password just doesn't show up and so, on pressing return, the Pi reverts to the original message, saying incorrect password. The login takes the word (pi) fine - it comes up on the screen, but trying to type anything in the password area does nothing. This is the obvious securi...
by jahboater
Wed Aug 03, 2016 9:07 am
Forum: Raspbian
Topic: /tmp to memory
Replies: 6
Views: 3692

Re: /tmp to memory

Thank you for the help and the Jessie version. :) It works with any version of Raspbian. Note that some Linux distros have /tmp as tmpfs anyway, but not Rasbian. I just add this same entry to fstab on all my Linux boxes: tmpfs /tmp tmpfs defaults,noatime 0 0 tmpfs /var/log tmpfs defaults,noatime,si...
by jahboater
Tue Aug 02, 2016 5:09 pm
Forum: Raspbian
Topic: /tmp to memory
Replies: 6
Views: 3692

Re: /tmp to memory

Add this to /etc/fstab

Code: Select all

tmpfs /tmp  tmpfs defaults,noatime 0 0
The maximum size is, by default, half of the system memory.
otherwise add ",size=XXXm" to set an upper limit to XXX megabytes.
by jahboater
Tue Aug 02, 2016 7:17 am
Forum: General discussion
Topic: Edit files on SD card
Replies: 22
Views: 30868

Re: Edit files on SD card

If you use a "live" cd or dvd such as Knoppix or one of the install cd's such as mint or ubuntu, these boot Linux directly off the cd/dvd (or usb drive) without touching the Windows file system at all. No software or driver needs installing, and they are free of course. Boot the machine from the liv...
by jahboater
Mon Aug 01, 2016 11:44 am
Forum: General discussion
Topic: Can we use windows Os and software in Raspberry Pi ?
Replies: 11
Views: 4527

Re: Can we use windows Os and software in Raspberry Pi ?

If you use the full version of Rasbian, then much of what you might want is already included, installed, and ready to go.
In your case, Raspbian includes a full Office suite that's compatible with MsOffice (called LibreOffice).
by jahboater
Mon Aug 01, 2016 10:21 am
Forum: General discussion
Topic: Will an RPi 3 Adjust To New Time Zone?
Replies: 4
Views: 869

Re: Will an RPi 3 Adjust To New Time Zone?

Or if you like the command line:-

Code: Select all

sudo dpkg-reconfigure tzdata
by jahboater
Sun Jul 31, 2016 9:49 am
Forum: Beginners
Topic: Raspberry pi without OS, ethernet, wifi and the network
Replies: 10
Views: 2322

Re: Raspberry pi without OS, ethernet, wifi and the network

Also of course in downloads, Raspbian Lite is very suitable for headless use.
by jahboater
Sun Jul 31, 2016 9:02 am
Forum: Troubleshooting
Topic: Lines of RED text during boot.
Replies: 8
Views: 1330

Re: Lines of RED text during boot.

lerner wrote:Is meaningless to me.
There are not time stamps on them, and it doesn't really help me identify which line is in RED when the machine boots.
The time stamp problem at least is easy: dmesg -T prints them out in human readable form. (see man dmesg).
by jahboater
Sun Jul 31, 2016 8:29 am
Forum: Off topic discussion
Topic: Speculate LONG term
Replies: 27
Views: 15556

Re: Speculate LONG term

On the clock frequency front, one can have an interesting time. I'm about to take delivery on a new gaming PC. Not particularly expensive as such things go, but it will have a 4GHz CPU. It uses water cooling, which is something I hope never to see required for a Pi, but I think there are some thing...
by jahboater
Sun Jul 31, 2016 8:05 am
Forum: Troubleshooting
Topic: Lines of RED text during boot.
Replies: 8
Views: 1330

Re: Lines of RED text during boot.

Try dmesg
by jahboater
Sun Jul 31, 2016 7:59 am
Forum: Beginners
Topic: How to choose the right raspberry pi for beginners?
Replies: 5
Views: 1641

Re: How to choose the right raspberry pi for beginners?

The official Pi3 power supply is 80.86% efficient and the Pi will use a lot less than 1A most of the time when its at idle (which it will be for this project) - and ignoring for now anything plugged into the USB ports. 1/3 of an amp or less would be closer. Less than 2W.

Mine stay on 24/7.
by jahboater
Sun Jul 31, 2016 7:31 am
Forum: General discussion
Topic: Don't know subfolders name?
Replies: 13
Views: 2089

Re: Don't know subfolders name?

What some posters were doing was a gentle version of RTFM...which for purposes of these forums is "Read the Fine Manual". The reason that people give answers like that is in an disparate hope that people will actually try to find answers out on their own before asking others to do it for them. If y...
by jahboater
Fri Jul 29, 2016 9:35 am
Forum: Bare metal, Assembly language
Topic: Assembler UAL syntax
Replies: 16
Views: 3204

Re: Assembler UAL syntax

And I am very much looking forward to the 64-bit version of Raspbian! For interest, this is a really good document:- http://115.28.165.193/down/arm/arch/ARM_v8_Instruction_Set_Architecture_(Overview).pdf BTW for now, you can run 64-bit linux on similar boards - the Pine64 or the Odroid-C2 (very fas...
by jahboater
Thu Jul 28, 2016 9:58 am
Forum: General discussion
Topic: Unique Serial Number
Replies: 21
Views: 16764

Re: Unique Serial Number

The serial number forms part of the MAC address, so I hope they are unique.
by jahboater
Wed Jul 27, 2016 12:56 pm
Forum: C/C++
Topic: Raspberry Pi 2 NEON instruction, vector report generation?
Replies: 6
Views: 1634

Re: Raspberry Pi 2 NEON instruction, vector report generatio

Does this help?

Code: Select all

-ftree-vectorize
by jahboater
Tue Jul 26, 2016 9:58 am
Forum: General discussion
Topic: Increase I2C speed
Replies: 14
Views: 3192

Re: Increase I2C speed

time(NULL) returns seconds with 6 digits after the coma so it's quit precise. I have displayed the number of seconds between each temperature measure. It displays 0.000000 second so i'm afraid i can't do better... Listen to what Joan said, and see "man 2 time" - time() definitely returns whole seco...
by jahboater
Mon Jul 25, 2016 6:55 pm
Forum: Raspbian
Topic: Reduce boot time, minimize sd corruption from power loss
Replies: 4
Views: 3206

Re: Reduce boot time, minimize sd corruption from power loss

A note about file system problems for anyone reading this post. The SD card has two partitions, a FAT partition for boot and the Ext4 partition for Linux. When an Ext4 partition and Linux is configured the correct way, you do not get problems from power failures. File system changes are written to ...
by jahboater
Mon Jul 25, 2016 1:33 pm
Forum: General discussion
Topic: power supply
Replies: 4
Views: 1090

Re: power supply

Here is the official PSU spec if it helps:
http://www.farnell.com/datasheets/2020825.pdf
by jahboater
Mon Jul 25, 2016 11:51 am
Forum: Advanced users
Topic: using a 256 GB SD card
Replies: 6
Views: 3585

Re: using a 256 GB SD card

If you used Win32DiskImager, there will be no trace of any previous partitions or filesystems remaining (same for dd of course).
Formatting prior to writing an image is 100% pointless.
A .img file is a complete, raw, disk image including the partition table.
by jahboater
Mon Jul 25, 2016 11:42 am
Forum: Bare metal, Assembly language
Topic: Assembler UAL syntax
Replies: 16
Views: 3204

Re: Assembler UAL syntax

Does this work for the old Model B ?

Code: Select all

    .cpu arm1176jzf-s
    .fpu vfp
    .syntax unified
I think the Pi2 would be "cortex-a7" and "neon-vfpv4".

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