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by R61zt
Mon Feb 06, 2017 10:30 am
Forum: Troubleshooting
Topic: problem with Apache2
Replies: 3
Views: 909

Re: problem with Apache2

Two unknowns which fit my screwups yesterday, do not fix your problem, but might give you some ideas to try: Changes in my config of apache2 (after restarting the daemon and apache2) were used by Firefox but not known to the default web browser yesterday. There might be some hardcoding (unknown) in ...
by R61zt
Fri Feb 03, 2017 4:30 pm
Forum: Automation, sensing and robotics
Topic: Scalextric Lap Timer & Race Control
Replies: 10
Views: 2832

Re: Scalextric Lap Timer & Race Control

I don't know the particular lap timer counter unit which you have, but I suggest that making a new one from scratch using IR beams, or magnets, or any other contraption which you can devise, would be a suitable hobby project and once you have got GPIO pins working, the program to do timer counting a...
by R61zt
Mon Jan 23, 2017 8:41 pm
Forum: Python
Topic: time.sleep and 75% CPU
Replies: 7
Views: 3017

Re: time.sleep and 75% CPU

I get nearly the same as ghp.
cpu on a 256 MB original 700MHz single core pi goes to 0.3% "python" for about a second while the i2c measurement readout is in progress and then stays on zero for the time.sleep(4.99) or comparable delay. memory use according to top shows steady 11.2MB "python".
by R61zt
Thu Jan 19, 2017 10:33 pm
Forum: Weather station
Topic: loose the yyyy-mm-dd and hh:mm:ss
Replies: 4
Views: 993

Re: loose the yyyy-mm-dd and hh:mm:ss

To save costs, the raspberry pi does not have a clock running (like the one on a PC motherboard near to the 3V coin battery). Buying a separate clock is an optional extra. IF you have an ethernet connection when you boot, it checks by Network Time Protocol ('NTP') what is your local time on the rest...
by R61zt
Thu Jan 19, 2017 4:13 pm
Forum: Troubleshooting
Topic: Power Supply Test RPi
Replies: 7
Views: 2070

Re: Power Supply Test RPi

Bwangster12
My opinion is based on old tests a few years ago.
With my 256MB old rPi, 4.9 to 5.1 Volts did work, and 5.3 did not.
It did my board no harm to try.
by R61zt
Thu Jan 19, 2017 3:53 pm
Forum: Beginners
Topic: PIR Sensor and Direction
Replies: 9
Views: 3973

Re: PIR Sensor and Direction

Yes, if you place the sensors far enough apart, for example near two ends of a corridor.
You can sketch a plan of your work area and on it sketch the wide fans of sensitivity of each sensor.
by R61zt
Thu Jan 19, 2017 3:49 pm
Forum: Beginners
Topic: How to set it up headlessly the first time???
Replies: 4
Views: 1545

Re: How to set it up headlessly the first time???

I've not tried the method of klricks. The following worked for me : remove the sd card and put it into the other raspberry pi which has keyboard, mouse, hdmi, (ethernet) boot that other raspberry pi after login as "pi" passwd to set a password raspi-config from that text menu, that lets you "enable"...
by R61zt
Thu Jan 19, 2017 3:38 pm
Forum: Beginners
Topic: PIR Sensor and Direction
Replies: 9
Views: 3973

Re: PIR Sensor and Direction

One PIR sensor will tell you only "present" or "not". Never mind that they might have more than one sense segment :- the built-in electronics is too small to poke or change in any way and your best bet is to buy more than one PIR sensor. The other way to do it, if you want millions of pixels, is wit...
by R61zt
Thu Jan 19, 2017 3:32 pm
Forum: Troubleshooting
Topic: Raspberry Pi laggy video
Replies: 10
Views: 4020

Re: Raspberry Pi laggy video

Updates creep seems to be removing known-good video codec formats and requiring newer ones which won't work without more than 20x as much memory as before and are not always available to download. For example, look up "youtube John West Salmon Bear" and see if you can find the bears fishing and kung...
by R61zt
Fri Jan 06, 2017 2:19 pm
Forum: Networking and servers
Topic: how can I send emails from my raspberry pi without gmail?
Replies: 17
Views: 8385

Re: how can I send emails from my raspberry pi without gmail

Try searching for "how do I make my raspberry pi into a high volume spam server" and see what you get ...
Alternatively, some internet searching for "warez" might do.
by R61zt
Fri Jan 06, 2017 1:55 pm
Forum: Troubleshooting
Topic: SSH - Putty Error
Replies: 20
Views: 4176

Re: SSH - Putty Error

Having posted the performance of my abnormal 256MB pi B, I think that I should post what a 'nice' newer one did. On an ordinary quad-core B2 with 1024 MB memory, running its desktop, opening a terminal /opt/vc/bin/vcgencmd measure_temp temp=35.8'C I've not tested this years' B3 but those have a high...
by R61zt
Thu Jan 05, 2017 9:16 pm
Forum: Troubleshooting
Topic: SSH - Putty Error
Replies: 20
Views: 4176

Re: SSH - Putty Error

Thanks. That measured T is 'normal' for electonics. My duff one is getting 68C now that I've slowed down the clock a little and got it working. Having eliminated 'same problem as me', I don't know what goes wrong with yours after a minute.
by R61zt
Thu Jan 05, 2017 8:38 pm
Forum: Media centres
Topic: multiple source audio question...
Replies: 6
Views: 1254

Re: multiple source audio question...

If it is just "beeps" and "dings" which you'll want, then try reading up on GPIO outputs. As a typical tiny loadspeaker in pound shop headphones is 30 ish Ohms, which is much too low to directly drive from a GPIO pin, one resistor and one npn transistor is sufficient to go from a GPIO output pin to ...
by R61zt
Thu Jan 05, 2017 8:12 pm
Forum: Windows 10 for IoT
Topic: info about lego trains controlled by Raspberry
Replies: 4
Views: 1771

Re: info about lego trains controlled by Raspberry

I'd skip the Win10 IoT thing entirely, buy a pinboard on 0.1 inch pitch and comparable bits and pieces to get from a few pins of the 40-way GPIO connector, a few resistors, a ten-pack of LED because those are nice for testing, a handful of bog standard npn transistors sufficient to switch the model ...
by R61zt
Thu Jan 05, 2017 7:58 pm
Forum: General discussion
Topic: Try something simpler first ?
Replies: 35
Views: 5160

Re: Try something simpler first ?

If you think that this forum is getting bad late homework panics, there is another hobby computer forum where kiddies ask "how do I build a robot?" and "how do I make a death ray?". Recommendation is that such people write (compile if it is in 'C') and chmod 700 a program to repeat a very large numb...
by R61zt
Thu Jan 05, 2017 7:46 pm
Forum: Beginners
Topic: Lost password
Replies: 5
Views: 2046

Re: Lost password

Passwords are placed somewhere so safe that you won't find it, and even if you did, would take thousands of days to decrypt. Your best bet on a low value home computer is to remove the sd card and manually copy any user files of value. On another linux computer those should show up from /media/<NAME...
by R61zt
Thu Jan 05, 2017 7:38 pm
Forum: Troubleshooting
Topic: SSH - Putty Error
Replies: 20
Views: 4176

Re: SSH - Putty Error

Taking care to not wear static-making fleece, and to touch the nearest grounded metal object such as a hot water pipe before doing this, how hot is the main dark square (the main chip) on top of your pi? My usual ones get warm and I had a faulty one which got too hot to touch and dropped ssh connect...
by R61zt
Thu Jan 05, 2017 7:28 pm
Forum: Troubleshooting
Topic: headless ssh connection refused
Replies: 2
Views: 2586

Re: headless ssh connection refused

I'm unsure about the default. Plugging the sd card into a raspberry pi which does have keyboard, mouse and hdmi attached, I typed sudo raspi-config and from the text menu selected enable ssh. While I was there, I gave it a more specific networkname than "raspberrypi". Powering off and moving the sd ...
by R61zt
Thu Sep 01, 2016 8:11 pm
Forum: Off topic discussion
Topic: Wishlist
Replies: 23
Views: 3870

Re: Wishlist

I'd suggest that PoE would be a nuisance to debug in a hobby setup so contrary to the rPi aims. In one morning I could solder on all 50 boards a red wire and a black wire for your 4.9 to 5.0 Volts supply. It is not hard and you can have any wishlist 2b you like. Mine won't boot from the 5.1V of an A...
by R61zt
Wed Aug 24, 2016 7:19 pm
Forum: Off topic discussion
Topic: Breakthrough Starshot - Mission: Alpha Centauri in 20 years?
Replies: 40
Views: 7021

Re: Breakthrough Starshot - Mission: Alpha Centauri in 20 ye

Much has been said about how far away 4 light years is. Rather than doing extra work to get a probe there within our lifetimes and get a signal back a few years later, how about an entirely different approach. How about getting all of the engineering knowledge of mankind onto a sort of "generation c...
by R61zt
Wed Aug 24, 2016 7:42 am
Forum: Troubleshooting
Topic: [Solved] Suddenly can't access my rpi except for ssh
Replies: 5
Views: 1622

Re: suddenly can't access my rpi except for ssh

This is unverified speculation: Do you have enough memory to do virtual machines ? I'm ok writing this from an old 512 MB pi, but I've been noticing that video and other tasks which used to work fine with 256MB now don't. Rather than virtualising (and using up precious memory) why not get a new sepa...
by R61zt
Tue Aug 23, 2016 10:32 am
Forum: Troubleshooting
Topic: Rpi B+ under voltage
Replies: 17
Views: 2582

Re: Rpi B+ under voltage

This is from old testing on an rPi B in 2013, so please could someone with newer hardware do this test with an adjustable benchtop dc supply to either confirm or deny these old findings : My rPi B 256 MB and B 512 MB were both able to boot only if supplied with between 4.9 and 5.0 Volts. That is, yo...
by R61zt
Sun Jun 12, 2016 8:22 pm
Forum: Beginners
Topic: Easiest programming language for controlling gpio pins
Replies: 10
Views: 5022

Re: Easiest programming language for controlling gpio pins

I'd recommend python for what you are doing.
by R61zt
Sun Jun 12, 2016 8:18 pm
Forum: Camera board
Topic: Camera trap
Replies: 21
Views: 4966

Re: Camera trap

How about linking two rPi with camera units, using GND and one digital pin on the GPIO to carry trigger information from either an external trigger or from one to the other.
by R61zt
Sun Jun 12, 2016 8:11 pm
Forum: Troubleshooting
Topic: USB not working and postulated keep-alive codes in updates
Replies: 0
Views: 330

USB not working and postulated keep-alive codes in updates

I don't post this out of spite. I have noticed that on raspberry pi A+, 256MB B, 512MB B and also on various Linux 2008 to 2016 editions and on Windows 7 that after a period of time (for example a year) at a location which does not have internet, it forgets how to make initial connection to various ...

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