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by davidcoton
Mon Feb 19, 2018 10:55 pm
Forum: Beginners
Topic: how do I uninstall programs?
Replies: 15
Views: 259

Re: how do I uninstall programs?

That all about installing, i won't to uninstall. In order to uninstall, you need to know (basically) how you installed it. Which instructions did you follow? Once we establish that, we can work out the magic uninstall (if there is one), or failing that, what to do to reverse the install, and what t...
by davidcoton
Mon Feb 19, 2018 9:03 pm
Forum: Troubleshooting
Topic: ssh and ping not working, but wifi still good
Replies: 2
Views: 46

Re: ssh and ping not working, but wifi still good

If the ssh has failed, and you send an email, does this restore ssh access?
The answer is still to get the Pi to periodically ping your router, that may be enough to keep WiFi alive. If not, do a reboot when the ping fails. IIRC there are posts about this sonewhere here -- search and you should find.
by davidcoton
Mon Feb 19, 2018 8:58 pm
Forum: Troubleshooting
Topic: Raspberry pi turns on without power cord.
Replies: 3
Views: 77

Re: Raspberry pi turns on without power cord.

Is this supposed to happen? Whether it is by design intention or omission, it is normal for a Pi1B. also, can this be bad, e.g. too much power for the raspberry pi? On an early Pi1B, the USB polyfuse may trip, temporarily stopping the backpowering from working. In any case, it bypasses the power pr...
by davidcoton
Mon Feb 19, 2018 8:45 pm
Forum: Beginners
Topic: how do I uninstall programs?
Replies: 15
Views: 259

Re: how do I uninstall programs?

Duid you follow these instructions ? They are a little old (Jessie not Stretch), and were tested on an older Pi2B, so there may be issues with Stretch on a Pi3. Some details are certainly out of date, but they are probably the best you can get as of now. You may need to contact JMRI on their Yahoo g...
by davidcoton
Sun Feb 18, 2018 10:42 pm
Forum: Troubleshooting
Topic: I fried my Raspberry Pi 3 B
Replies: 8
Views: 213

Re: I fried my Raspberry Pi 3 B

If you are lucky and removing D5 does make the Pi work, then get a replacement diode and fit it ASAP. As at least one person has reported, running without D5 and repeating the overvolt error is completely and irrevokably fatal to the Pi. :o :shock: :? :roll: :(
by davidcoton
Sun Feb 18, 2018 9:42 pm
Forum: General discussion
Topic: Advice requested for use as small file server
Replies: 16
Views: 535

Re: Advice requested for use as small file server

AIUI PiClone is a part of the Stretch with Desktop download, not sure about Lite. I haven't checked so I may be wrong.
by davidcoton
Sun Feb 18, 2018 4:17 pm
Forum: General discussion
Topic: Raspberry PI Zero W - Mounting hole size?
Replies: 12
Views: 451

Re: Raspberry PI Zero W - Mounting hole size?

Are you implying the Australia is outside any major conurbations? Assuming Australia actually exists, and that one or more major conurbations exist, we know that Australia is not inside any major conurbation, because on the accepted standard sizes it won't fit, therefore, Australia is outside any m...
by davidcoton
Sun Feb 18, 2018 3:34 pm
Forum: Off topic discussion
Topic: Pi's on TV
Replies: 4
Views: 970

Re: Pi's on TV

*Unimportant = Not a reality show watching people bickering or trying to get rich quick, not another way to cook chicken. Not, yet some more comments on some foreign politician and his tweets that no one really cares about. Clearly what we need is a reality show where contestants (politicians) are ...
by davidcoton
Sun Feb 18, 2018 3:06 pm
Forum: General discussion
Topic: Same code, compiler version, and HW. Different results
Replies: 30
Views: 890

Re: Same code, compiler version, and HW. Different results

@Heater, since the matter is so obvious I look forward to the Heater+++ language compiler, which will of course be comprehensive, multi-purpose, intuitive and easy to use, versatile, bug free, cross platform, and entirely free of undefined or inconsistent behaviour. It should only take a couple of d...
by davidcoton
Fri Feb 16, 2018 1:51 pm
Forum: General discussion
Topic: Raspberry Pi current felt!!!?
Replies: 38
Views: 1362

Re: Raspberry Pi current felt!!!?

mahjongg wrote:
Fri Feb 16, 2018 12:33 pm
The "fault" is that the user plugs a power supply with a grounded plug into an ungrounded outlet.
Isn't that what i said?
by davidcoton
Thu Feb 15, 2018 11:17 pm
Forum: Troubleshooting
Topic: WiFi only connects with static IP?
Replies: 10
Views: 255

Re: WiFi only connects with static IP?

Is the ssid of your network hidden?
If so:

Code: Select all

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=yourcountrycode

network={
     ssid="Your network name/SSID"
     psk="Your WPA/WPA2 security key"
     scan_ssid=1
     key_mgmt=WPA-PSK
}
with the appropriate localisation
by davidcoton
Thu Feb 15, 2018 11:08 pm
Forum: Troubleshooting
Topic: Raspbian Stretch With Desktop - 11/29/2017
Replies: 15
Views: 372

Re: Raspbian Stretch With Desktop - 11/29/2017

Does your network hide its ssid? If so, add a line as follows:

Code: Select all

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=BR

network={
	ssid="YVirus"
	psk="my password here"
	scan_ssid=1
	key_mgmt=WPA-PSK
}
The other possibility is that you network is not running WPA security?
by davidcoton
Thu Feb 15, 2018 10:18 pm
Forum: General discussion
Topic: Raspberry PI Zero W - Mounting hole size?
Replies: 12
Views: 451

Re: Raspberry PI Zero W - Mounting hole size?

And internationally:
https://www.google.co.uk/search?q=m2.5+ ... 20&bih=966
(if that doesn't work in non-Firefox browsers, just try the Google shopping option for "M2.5 screw")
by davidcoton
Thu Feb 15, 2018 10:10 pm
Forum: General discussion
Topic: Advice requested for use as small file server
Replies: 16
Views: 535

Re: Advice requested for use as small file server

In that scenario storing the scans on the SDCard is fine. Raspbian has a program called PiClone that will write a backup of the SDCard. Stick to Raspbian with Desktop. The only disadvantage is that it carries some extra software "bloat" that you won't use in a server. Even with the GUI available, yo...
by davidcoton
Thu Feb 15, 2018 9:58 pm
Forum: General discussion
Topic: Raspberry Pi current felt!!!?
Replies: 38
Views: 1362

Re: Raspberry Pi current felt!!!?

Perhaps I have not worded it exactly right, but I hope my comment that "under certain circumstances its possible that the ground wire of an unearthed device can carry halve the mains voltage, due to the effect of the two filter caps in its power supply", has not been lost. Any Class I equipment wit...
by davidcoton
Wed Feb 14, 2018 9:50 pm
Forum: General discussion
Topic: Advice requested for use as small file server
Replies: 16
Views: 535

Re: Advice requested for use as small file server

Dear davidcoton, Thanks for your reply. I've used the quote function to answer your questions. Thanks for the OS suggestions. How many documents are you scanning each hour/day/week? Depends from day to day or week to week. I guess an average of no more then 5 docs per day. What size are the scan fi...
by davidcoton
Wed Feb 14, 2018 6:09 pm
Forum: Beginners
Topic: convert 12V to 5V
Replies: 15
Views: 573

Re: convert 12V to 5V

A fuse does not protect a device upstream it protects things down stream. So a fuse in the 5v supply from your DC-DC converter would protect the DC-DC converter in the event of your pi causing an overload or short circuit on the 5v or a short circuit on the 5v wiring feeding the pi. and a fuse on t...
by davidcoton
Wed Feb 14, 2018 5:58 pm
Forum: General discussion
Topic: Raspberry Pi current felt!!!?
Replies: 38
Views: 1362

Re: Raspberry Pi current felt!!!?

You can use your water leads as ground, the (metal) pipes are normally grounded at some point, don't tell me you don't have a water supply with metal tubing? Actually in the UK it quite common for new builds and replacement supplies to be run in all plastic pipe work for both gas and water supplies...
by davidcoton
Wed Feb 14, 2018 11:28 am
Forum: General discussion
Topic: "U5" in raspberry pi3 model B
Replies: 3
Views: 249

Re: "U5" in raspberry pi3 model B

The schematic is not complete. Only the parts affecting the connections that might be made to the board are published. The Pi hardware is not open source. The partial schematic and the board itself are the only public information to identifiy the parts. It doesn't matter to me, but if you want infor...
by davidcoton
Wed Feb 14, 2018 10:29 am
Forum: Advanced users
Topic: Booting from usb advice needed
Replies: 33
Views: 695

Re: Booting from usb advice needed

Am I missing something here... Why would it be a problem when booting from the USB drive as the SD card has to be removed (otherwise it will boot from t the SDCard). PeterO @PeterO, I think you are missing two things: The OP talks about Booting from USB is easy on a Pi1, Pi2, or Pi3 which implies i...
by davidcoton
Wed Feb 14, 2018 10:19 am
Forum: Troubleshooting
Topic: Broke off power connector and polyfuse, any chance of repair?
Replies: 2
Views: 76

Re: Broke off power connector and polyfuse, any chance of repair?

Any repair will involve soldering. It may be repairable by a competent technician, but I suspect there is too much damage to the tracks on the board. It should be possible to mount a new connector and polyfuse externally and connect the output from that to test point pp35 (and pp3,4,5 or 6 as ground...
by davidcoton
Wed Feb 14, 2018 12:21 am
Forum: Beginners
Topic: How can i connect a 8 circuit Molex receptacle to a raspberry pi?
Replies: 4
Views: 146

Re: How can i connect a 8 circuit Molex receptacle to a raspberry pi?

I hope you have checked that the voltages on the interfaces are compatible with the Pi?
by davidcoton
Tue Feb 13, 2018 10:30 pm
Forum: Beginners
Topic: High V\I Power Bank
Replies: 3
Views: 120

Re: High V\I Power Bank

+1. Be aware also that the capacity of power banks is often quoted in Ah at the battery voltage, not at the 5V output voltage. Do all your comparisons in Wh to avoid that pitfall.
by davidcoton
Tue Feb 13, 2018 10:27 pm
Forum: General discussion
Topic: Advice requested for use as small file server
Replies: 16
Views: 535

Re: Advice requested for use as small file server

How many documents are you scanning each hour/day/week? What size are the scan files? How many accesses to each file? Subject to the data rate (and storage capacity, but that is solvable) a Pi3B should be suitable. The standard OS is Raspbian, another Debian variant, but much better supported than L...
by davidcoton
Tue Feb 13, 2018 10:17 pm
Forum: Off topic discussion
Topic: It *has* to happen!
Replies: 28
Views: 1109

Re: It *has* to happen!

I think it is 4824 before you have > 50% chance of having 2 with the same address if you have n RPis the number of possible pairs is n(n-1)/2. Each pair has a probability of 1 in 2^24 of having the same MAC. So for a 50% probability of one pair with both MACs the same you need (2^24)/2 pairs Puttin...

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