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by dgordon42
Sun Sep 03, 2017 12:10 pm
Forum: Raspbian
Topic: Re: Booting Stretch to the CLI with NumLock on [Solved]
Replies: 9
Views: 3356

Re: Booting Stretch to the CLI with NumLock on [Solved]

Has anyone found a way to boot a fresh copy of Raspbian Stretch to the CLI with NumLock on? In Jessie, I could set (uncomment) "LEDS=+num" in '/etc/kbd/config' to do this, but the '/etc/kbd/' directory is not present in Stretch by default. I have tried adding "LEDS=+num" to the '/etc/default/console...
by dgordon42
Fri Aug 25, 2017 3:32 pm
Forum: Beginners
Topic: [solved]noobs with stretch?
Replies: 2
Views: 688

Re: noobs with stretch?

Yes.

Dave.
by dgordon42
Mon Aug 21, 2017 1:03 pm
Forum: General discussion
Topic: RaspberryPi3 about Certification
Replies: 1
Views: 418

Re: RaspberryPi3 about Certification

Have you seen this Blog post?

Hope this helps,
Dave.
by dgordon42
Wed Aug 16, 2017 3:49 pm
Forum: General discussion
Topic: HC-05 max baudrate?
Replies: 3
Views: 2552

Re: HC-05 max baudrate?

I have to agree with @MarkTF above. I have an old DEC VT320 terminal connected to my Pi at 9600 baud, and Vim scrolls through a 24 line by 80 character screen in about 1 second without missing lines or any hesitations.

Dave.
by dgordon42
Wed Jul 26, 2017 2:55 pm
Forum: Beginners
Topic: Documentation: Shell Scripts
Replies: 7
Views: 1573

Re: Documentation: Shell Scripts

The page you referenced contains a Bash Script, not a Python Script, and so you should NOT add the '.py' suffix to the file name. Is there maybe an error in the documentation (very frustrating for newbies!) or am I doing something wrong? The instructions on the page work for me, I don't see any erro...
by dgordon42
Mon Jul 24, 2017 3:46 pm
Forum: Troubleshooting
Topic: Wifi connection unstable
Replies: 59
Views: 38542

Re: Wifi connection unstable

From your 'iwconfig' posting: Link Quality=25/70 Signal level=-85 dBm With my Pi 3B, the WiFi performance starts to drop off when the Link Quality drops below 50. Try moving your Pi and/or router to get a better signal. If this is not possible there are some WiFi USB Dongles out there which have gre...
by dgordon42
Mon Jul 24, 2017 12:00 pm
Forum: Beginners
Topic: Dumb python newbie question
Replies: 12
Views: 1710

Re: Dumb python newbie question

Open and run it in Thonny IDE in Pi, this line from Tkinter import * immidately give me a error saying that "No module named 'Tkinter'" If you change the first line of your program, "from Tkinter import *" to: from tkinter import * your code will run in Python 3, and therefor should run in Thonny. ...
by dgordon42
Thu Jul 13, 2017 3:40 pm
Forum: Troubleshooting
Topic: Make serial port working on Rasp 3 Model B
Replies: 8
Views: 2411

Re: Make serial port working on Rasp 3 Model B

I've never used picocom. You can do a 'Loopback' check of your Serial Port by shorting the Serial Tx and Rx GPIO pins together (power down your Pi first!) and running this Python Script: #!/usr/bin/env python3 # -*- coding: utf-8 -*- # serial_port_loopback3.py # Will also work on Python2. # Serial p...
by dgordon42
Thu Jul 13, 2017 11:31 am
Forum: Troubleshooting
Topic: Make serial port working on Rasp 3 Model B
Replies: 8
Views: 2411

Re: Make serial port working on Rasp 3 Model B

You have chosen to disable Bluetooth on your Pi (which is fine) with the line: dtoverlay=pi3-disable-bt Disabling Bluetooth also involves running the once off command: sudo systemctl disable hciuart and rebooting. Have you done this? (Details in the '/boot/overlays/README' file.) 3) /etc/inittab Cod...
by dgordon42
Sun Jul 09, 2017 1:50 pm
Forum: Troubleshooting
Topic: pi zero w test pads for extra USB [solved]
Replies: 21
Views: 13024

Re: pi zero w test pads for extra USB

It's worth noting that hot plugging USB devices to the original model A and B Pi's also caused them to crash & reboot. The model B+ (and later models) have extra power management circuitry in the 5V USB power supply to allow hot plugging of USB devices, among other things. This USB power management ...
by dgordon42
Fri Jul 07, 2017 2:41 pm
Forum: C/C++
Topic: new procedure to enable Pi 2 UART pins for C programs?
Replies: 12
Views: 3539

Re: new procedure to enable Pi 2 UART pins for C programs?

Does that method (good old traditional method :-)) Also need $ sudo systemctl stop [email protected].service $ sudo systemctl disable [email protected].service As far as I know, no. Removing "Console=serial0,115200" from '/boot/config.txt' is enough. It prevents the Linux Kernel from setting ...
by dgordon42
Fri Jul 07, 2017 1:22 pm
Forum: C/C++
Topic: new procedure to enable Pi 2 UART pins for C programs?
Replies: 12
Views: 3539

Re: new procedure to enable Pi 2 UART pins for C programs?

To complement @bensimmo's post above, if you cannot or do not wish to use 'raspi-config', you can achieve the same results by: 1. Add the line enable_uart=1 to the '/boot/config.txt' file, this line will set up the Serial Port UART and the necessary clocks on all Pi models. 2. Remove the phrase "con...
by dgordon42
Fri Jul 07, 2017 11:47 am
Forum: Beginners
Topic: Is there a way to disable wifi and bluetooth via hardware?
Replies: 11
Views: 3497

Re: Is there a way to disable wifi and bluetooth via hardwar

The reason why i ask about disabling it manually is because i'm worried about getting hacked while connected to the internet thus i'd like to minimize the time connected to the internet. The problem with a software based solution (as mentioned via terminal) is that if a trojan cracked the computer ...
by dgordon42
Mon Jul 03, 2017 1:59 pm
Forum: Troubleshooting
Topic: Pi 3B UART limited to 9 chars?
Replies: 17
Views: 3474

Re: Pi 3B UART limited to 9 chars?

This Serial Port bug on 'ttyS0' appears to be fixed with the release of the 4.9.35, #1014 kernel dated 30 Jun 2017, released to 'apt-get' today.

Thanks,
Dave.
by dgordon42
Mon Jul 03, 2017 1:16 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Using i2c0 on PI3?
Replies: 2
Views: 2427

Re: Using i2c0 on PI3?

See this post.

Dave.
by dgordon42
Sat Jul 01, 2017 2:52 pm
Forum: Troubleshooting
Topic: Pi2 - no booting / bad extra_isize error
Replies: 6
Views: 3869

Re: Pi2 - no booting / bad extra_isize error

Have you tried running 'fsck' on your bad SD Card.
The card should be unmounted for 'fsck' to do it's stuff. Run it separately on the two partitions on the Card.
It may or may not work, depending on what's wrong with the Card.

Code: Select all

man fsck
Good Luck,
Dave.
by dgordon42
Fri Jun 30, 2017 10:36 am
Forum: Troubleshooting
Topic: /dev/ttyUSB0 Serial Port Not working
Replies: 7
Views: 21702

Re: /dev/ttyUSB0 Serial Port Not working

While your Pi is up and running, disconnect your Serial to USB Converter, wait 10 seconds or so, and reconnect it again. Give it another 10 - 20 seconds, then run: tail -20 /var/log/syslog You should see something like: Jun 30 11:28:08 RaspberryThree kernel: [243857.673330] usb 1-1.3: new full-speed...
by dgordon42
Thu Jun 29, 2017 2:58 pm
Forum: Troubleshooting
Topic: /dev/ttyUSB0 Serial Port Not working
Replies: 7
Views: 21702

Re: /dev/ttyUSB0 Serial Port Not working

It's possible that SystemD is setting up a Linux Console on your Serial to USB Converter when you plug it into your Pi, and this prevents other applications like your Python program from talking to the port. With your USB Converter plugged into your Pi, try running: sudo systemctl status serial-gett...
by dgordon42
Wed Jun 28, 2017 2:35 pm
Forum: Troubleshooting
Topic: Unable to read on serial port whereas I can write
Replies: 10
Views: 4008

Re: Unable to read on serial port whereas I can write

If you are using a Pi Zero (not a Pi Zero W), then the '/dev/ttyS0' UART is not connected to the GPIO Serial Port pins by default, '/dev/ttyAMA0' is. I suggest that you change ALL INSTANCES of '/dev/ttyS0' to '/dev/serial0' in your code. Thats serialZero, not serialOh. You should also add the line: ...
by dgordon42
Tue Jun 27, 2017 3:40 pm
Forum: Troubleshooting
Topic: Bluetooth serial communication
Replies: 22
Views: 4141

Re: Bluetooth serial communication

I find the best way to sort out the Pi's GPIO naming muddle is to run:

Code: Select all

gpio readall
in a terminal.
It draws a nice ASCII picture showing the physical pins, their voltage levels, their mode, their name, their WiringPi number and their Broadcom number.

Hope this helps,
Dave.
by dgordon42
Tue Jun 27, 2017 11:02 am
Forum: Troubleshooting
Topic: Serial port Pemission Denied
Replies: 9
Views: 9642

Re: Serial port Pemission Denied

As a general rule, you should never change the ownership or permissions of Linux system files. It is not necessary to change any ownership or permissions of any files to use the serial port on any model of Raspberry Pi. Changing ownership or permissions of Linux system files just opens up security h...
by dgordon42
Sat Jun 24, 2017 7:17 pm
Forum: Beginners
Topic: A simple screen for my PI
Replies: 6
Views: 4018

Re: A simple screen for my PI

Have you considered the Offical RaspberryPi Screen?
Although it's not HDMI, when you connect it to a Pi, it's auto-detected and just works.
The main drawback is that it does not come with any kind of enclosure, but Google can find a few suitable cases out there.

Hope this helps,
Dave.
by dgordon42
Thu Jun 22, 2017 8:13 pm
Forum: C/C++
Topic: problem in using serail port in raspberry model 3
Replies: 2
Views: 592

Re: problem in using serail port in raspberry model 3

Unfortunately the two web pages of instructions you have linked to are 3 years old, and don't work on a Pi 3B. First, can you confirm that the USB connection of your usb-serial converter (PL2303) is connected to the Pi and the Serial Port pins are connected to the PC, or is it the other way around? ...
by dgordon42
Thu Jun 22, 2017 7:37 pm
Forum: Troubleshooting
Topic: Serial port Pemission Denied
Replies: 9
Views: 9642

Re: Serial port Pemission Denied

Your Pi may not be configured correctly to use the Serial Port. Post the output of the following commands: uname -a cat /boot/cmdline.txt grep -v ^\# /boot/config.txt ls -lh /dev/serial* In addition, you should refer to your Serial Port in code as "/dev/serial0", not "/dev/ttyAMA0" or "/dev/ttyS0". ...
by dgordon42
Wed Jun 21, 2017 6:51 pm
Forum: Troubleshooting
Topic: No xlxs, doc opens in libre. just sits there
Replies: 2
Views: 399

Re: No xlxs, doc opens in libre. just sits there

Right Click on your '.xlsx' file, select 'Properties', then select the 'Permissions' tab.
Do you have permission to read and write to the file?

Dave.

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