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by DougieLawson
Mon Aug 20, 2018 9:25 am
Forum: Beginners
Topic: can't boot PI3 after dropping the heat sink onto the board by accident
Replies: 10
Views: 174

Re: can't boot PI3 after dropping the heat sink onto the board by accident

You can. Although my Electronics 101 is a low voltage course. High power @ 400Kv is a topic for another day.
by DougieLawson
Mon Aug 20, 2018 8:13 am
Forum: Troubleshooting
Topic: Raspberry pi 3 not rebooting from usb
Replies: 9
Views: 120

Re: Raspberry pi 3 not rebooting from usb

B.Goode wrote:
Mon Aug 20, 2018 8:05 am
Although it isn't explicit in https://www.raspberrypi.org/documentati ... ootflow.md, perhaps this is expected behaviour?
No, it's a bug in kernel/bootcode. I thought it had been resolved with a recent update, perhaps not.
by DougieLawson
Mon Aug 20, 2018 8:09 am
Forum: Python
Topic: QR scanner output using HID
Replies: 2
Views: 28

Re: QR scanner output using HID

You're getting HID data as documented on page 53 of http://www.usb.org/developers/hidpage/Hut1_12v2.pdf

The first byte is a bit string (the 0x2 bit means shift). The third byte is "usage ID" (as in the PDF).
by DougieLawson
Mon Aug 20, 2018 7:57 am
Forum: Troubleshooting
Topic: Raspberry pi 3 not rebooting from usb
Replies: 9
Views: 120

Re: Raspberry pi 3 not rebooting from usb

What kernel version do you have? What bootcode version?

uname -a
vcgencmd version


will tell us.
by DougieLawson
Mon Aug 20, 2018 7:28 am
Forum: Troubleshooting
Topic: Raspberry pi 3 not rebooting from usb
Replies: 9
Views: 120

Re: Raspberry pi 3 not rebooting from usb

Run sudo apt update && sudo apt -y dist-upgrade

That will get you new bootcode and a new kernel that will fix your problem.
by DougieLawson
Mon Aug 20, 2018 6:46 am
Forum: Beginners
Topic: can't boot PI3 after dropping the heat sink onto the board by accident
Replies: 10
Views: 174

Re: can't boot PI3 after dropping the heat sink onto the board by accident

There's no slack to cut. Day 1, electronics 101 has three things to learn.
  1. Polarity
  2. Ohms Law
  3. Power off before changing things
that's it. That's the syllabus for the first day of the course.
by DougieLawson
Sun Aug 19, 2018 10:54 pm
Forum: Beginners
Topic: can't boot PI3 after dropping the heat sink onto the board by accident
Replies: 10
Views: 174

Re: can't boot PI3 after dropping the heat sink onto the board by accident

Why would anyone try to mount a heatsink with the board powered up? There's too much chance to short 3V3 to GND, short 5V to 3V3 or short 5V to GND. Shorting pins is a good way to shoot a Raspberry Pi very (and unreviveably) dead.
by DougieLawson
Sun Aug 19, 2018 9:48 pm
Forum: Français
Topic: Je n'arrive pas à extraire un fichier rar
Replies: 18
Views: 231

Re: Je n'arrive pas à extraire un fichier rar

Le code d'erreur 0x80070018 (-2147024872) signifie que votre fichier RAR est endommagé.
by DougieLawson
Sun Aug 19, 2018 9:16 pm
Forum: Français
Topic: Je n'arrive pas à extraire un fichier rar
Replies: 18
Views: 231

Re: Je n'arrive pas à extraire un fichier rar

Taper ça: 7z e -o/home/pi/Downloads test.rar sans espace.
by DougieLawson
Sun Aug 19, 2018 1:56 pm
Forum: Python
Topic: Multiple DS18B20 Sensors on 20x4 LCD
Replies: 39
Views: 415

Re: Multiple DS18B20 Sensors on 20x4 LCD

So you can use that to avoid hard-coding sensor names in your programs. Which is a "Good thing®" as it means you don't have to muck about when you add a new sensor or replace a broken one.
by DougieLawson
Sun Aug 19, 2018 1:43 pm
Forum: Troubleshooting
Topic: Ip resolves to local host
Replies: 11
Views: 234

Re: Ip resolves to local host

I've a feeling https://codex.wordpress.org/Changing_The_Site_URL is the answer the OP is trying to find.
by DougieLawson
Sun Aug 19, 2018 1:35 pm
Forum: Advanced users
Topic: My SQL on pi 3 b+?
Replies: 6
Views: 93

Re: My SQL on pi 3 b+?

MySQL got replaced with MariaDB which is equivalent but not owned by Oracle. sudo apt install mariadb-server-10.1 mariadb-client-10.1 python{,3}-mysql.connector should get it installed. MSSQL can be accessed using unixodbc, although the server still runs on a Microsoft machine. Don't know squat abou...
by DougieLawson
Sun Aug 19, 2018 1:29 pm
Forum: Python
Topic: Multiple DS18B20 Sensors on 20x4 LCD
Replies: 39
Views: 415

Re: Multiple DS18B20 Sensors on 20x4 LCD

Just try my small snippet of code - see what it gives you.
by DougieLawson
Sun Aug 19, 2018 1:08 pm
Forum: Python
Topic: Multiple DS18B20 Sensors on 20x4 LCD
Replies: 39
Views: 415

Re: Multiple DS18B20 Sensors on 20x4 LCD

Rather than using an array of sensorids why not use glob to find them.

Code: Select all

#!/usr/bin/python3
import glob

sysDir = '/sys/bus/w1/devices/'
w1Devices = glob.glob(sysDir + '28*')
for w1Dev in w1Devices:
  w1Slave = w1Dev + '/w1_slave'
  print (w1Slave)
by DougieLawson
Sun Aug 19, 2018 10:05 am
Forum: Beginners
Topic: No video out of jack socket. Pi3 B+
Replies: 25
Views: 322

Re: No video out of jack socket. Pi3 B+

Mikexx wrote:
Sun Aug 19, 2018 9:45 am
What is the point of Noobs?
There is no point to NOOBS if you aren't using it as a multi-boot manager (and for that you should switch to PINN). I've not yet worked out why the RPF folks haven't moved NOOBS into the annals of history, it does nothing useful (now).
by DougieLawson
Sun Aug 19, 2018 10:03 am
Forum: Raspbian
Topic: Should we be using apt full-upgrade
Replies: 5
Views: 116

Re: Should we be using apt full-upgrade

ShiftPlusOne wrote:
Sun Aug 19, 2018 9:42 am
I'm not in front of a computer, so can't check. I think it's the same as dist-upgrade, but for 'apt'. Since dist-upgrade was a misnomer which resulted in a lot of confusion.
I am in front of a computer and I have checked. Docs say full-upgrade is an alias for dist-upgrade.
by DougieLawson
Sun Aug 19, 2018 9:41 am
Forum: Raspbian
Topic: Should we be using apt full-upgrade
Replies: 5
Views: 116

Re: Should we be using apt full-upgrade

full-upgrade is equivalent to dist-upgrade (runs exactly the same function).

The important thing is NEVER run rpi-update. You don't know what you're getting with rpi-update as it can give you an experimental kernel and untested bootcode.
by DougieLawson
Sun Aug 19, 2018 9:39 am
Forum: Troubleshooting
Topic: Raspberry PI loads in emergency mode - always
Replies: 10
Views: 184

Re: Raspberry PI loads in emergency mode - always

this was suggested by the seller ( where I also bought my PI ). At first i thought i'll run it only with SD card. Bought external disk later. ... but it is true that on picture 2 is visible that this power supply dont have these edges anymore, so it falls out of the PI easily (but it seems it worke...
by DougieLawson
Sun Aug 19, 2018 9:17 am
Forum: General discussion
Topic: How can I make a sound repeat?
Replies: 1
Views: 10

Re: How can I make a sound repeat?

Change it to

while true ; do aplay file.wav ; done

https://www.cyberciti.biz/faq/bash-infinite-loop/
by DougieLawson
Sun Aug 19, 2018 8:40 am
Forum: Automation, sensing and robotics
Topic: A DIY smart doorbell for $40 with RPi 2/3
Replies: 3
Views: 14566

Re: A DIY smart doorbell for $40 with RPi 2/3

Your question is really "Does Prota OS on the RPi support the camera module?".
https://prota.info/prota/pi/

https://naranhelp.zendesk.com/hc/en-us/ ... ra-support
by DougieLawson
Sun Aug 19, 2018 8:16 am
Forum: Troubleshooting
Topic: Raspberry PI loads in emergency mode - always
Replies: 10
Views: 184

Re: Raspberry PI loads in emergency mode - always

Do you have a good enough power supply? Not a phone charger.
by DougieLawson
Sun Aug 19, 2018 12:14 am
Forum: Add-ons
Topic: ETA for Official POE Hat for 3B+
Replies: 52
Views: 1162

Re: ETA for Official POE Hat for 3B+

Have you run sudo apt update && sudo apt -y dist-upgrade to ensure you have the latest stable kernel and bootcode (which is required for the POE HAT)?
by DougieLawson
Sun Aug 19, 2018 12:02 am
Forum: Python
Topic: noobie needs help getting data from XML webpage
Replies: 4
Views: 79

Re: noobie needs help getting data from XML webpage

I hacked this python3 program together to parse some of the XML from the Aviation Weather Service (I've downloaded a sample XML file from EGLL (London Heathrow)). #!/usr/bin/python3 from bs4 import BeautifulSoup infile = open('egll.xml', 'r') # CHANGE ME to fetch the current URL contents = infile.re...

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