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by dgordon42
Thu Nov 29, 2018 9:27 pm
Forum: General discussion
Topic: Current way to disable getty?
Replies: 1
Views: 98

Re: Current way to disable getty?

It you want to stop a getty running on the Serial Port (which is disabled by default these days I believe) then try:

Code: Select all

sudo systemctl stop [email protected]
or

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sudo systemctl stop [email protected]
as required.

Hope this helps,
Dave.
by dgordon42
Mon Oct 29, 2018 4:46 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: [RPi Zero W] UART not working when SPI1 enabled
Replies: 9
Views: 3402

Re: [RPi Zero W] UART not working when SPI1 enabled

I ran the commands you listed. Here is the output: 1. Linux MY_PI'S_NAME 4.14.71+ #1145 Fri Sep 21 15:06:38 BST 2018 armv6l GNU/Linux 2. dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait modules-load=dwc2,g_ether,g_mass_storage 3. enabl...
by dgordon42
Tue Oct 23, 2018 9:27 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: [RPi Zero W] UART not working when SPI1 enabled
Replies: 9
Views: 3402

Re: [RPi Zero W] UART not working when SPI1 enabled

Good catch, thanks.
I've edited my post above.

Dave.
by dgordon42
Tue Oct 23, 2018 9:19 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: [RPi Zero W] UART not working when SPI1 enabled
Replies: 9
Views: 3402

Re: [RPi Zero W] UART not working when SPI1 enabled

As a quick fix, try changing "/dev/ttyAMA0" in your Python3 script to "/dev/serial0" and run it again. Thats SerialZero, not SerialOh.

If that does not help, report the output of the following commands:

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uname -a
cat /boot/cmdline.txt
grep -v -e ^# -e ^$ /boot/config.txt
Thanks,
Dave.
by dgordon42
Sat Oct 06, 2018 4:36 pm
Forum: Troubleshooting
Topic: raspbian stretch lite wpa_supplicant.conf
Replies: 9
Views: 431

Re: raspbian stretch lite wpa_supplicant.conf

flamner wrote:
Sat Oct 06, 2018 5:30 am

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

network={
    ssid="NAME"
    scan_ssid=1
    psk="PASSWD"
    key_mgmt=WPA-PSK
}
Try it without the "scan_ssid=1" line.

Hope this helps,
Dave.
by dgordon42
Sun Sep 30, 2018 11:18 am
Forum: Python
Topic: Intermediate python and general programming ressources
Replies: 4
Views: 384

Re: Intermediate python and general programming ressources

After reading the Al Sweigart books you mention, I found a good next step to be the 6.00 series courses on EDx. There are 2 courses in the series, and they get revised from time to time: 6.00.1x 6.00.2x They are available free of charge, and designed for people with just a little programming experie...
by dgordon42
Tue Sep 25, 2018 11:24 am
Forum: Beginners
Topic: Remote desktop connection shows only checkerboard
Replies: 1
Views: 106

Re: Remote desktop connection shows only checkerboard

These days RaspberryPis come with the RealVNC installed by default. More details here. I found it works better than the old xrdp connection. If you want to use xrdp, then you will have to purge RealVNC from your Pi first, then install xrdp on your Pi. RealVNC and xrdp are not compatible (they use th...
by dgordon42
Wed Sep 19, 2018 3:45 pm
Forum: General discussion
Topic: RPI3 RxTx Connection with a weight machine [HELP!]
Replies: 1
Views: 137

Re: RPI3 RxTx Connection with a weight machine [HELP!]

Lots of questions here, I'll have a go at some of them. Actually I wired my raspberry using RxTx with RS232 linked to the weight machine but now I don't really know what to do on my raspberry, I followed some tutorials to use the ports. First of all you must be aware that the RaspberryPi's Serial Po...
by dgordon42
Wed Sep 19, 2018 12:37 pm
Forum: Troubleshooting
Topic: Basic UART loopback communication issues
Replies: 17
Views: 4764

Re: Basic UART loopback communication issues

@mungojerry: The method you have posted will work on all models of Pi releases to date running an up to date Raspbian OS by default. However, @Ennud above was not running his Pi in a default configuration, he was running a Bluetooth equipped model with Bluetooth disabled, hence his need to disable '...
by dgordon42
Mon Sep 10, 2018 10:26 am
Forum: General discussion
Topic: Pi 3 Serial Issues
Replies: 30
Views: 43328

Re: Pi 3 Serial Issues

I have checked with the command rcv.decode('utf-8') after rcv = port.read() but it was giving error as "bytes object has no attribute as encode". That is why I wanted you to try encode . Python2 will print bytes as ASCII characters, but Python3 will not. You need to encode the bytes into UTF-8 char...
by dgordon42
Fri Sep 07, 2018 1:17 pm
Forum: General discussion
Topic: Pi 3 Serial Issues
Replies: 30
Views: 43328

Re: Pi 3 Serial Issues

Python2 and Python3 handle ASCII and Unicode characters differently.
After the line:

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rcv = port.read(400)
in your code, add the line:

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rcv.encode('utf-8')
and see what happens.

Good Luck,
Dave.
by dgordon42
Sat Aug 25, 2018 7:59 pm
Forum: Raspberry Pi Desktop for PC and Mac
Topic: WiFi will not work after install on laptop
Replies: 11
Views: 840

Re: WiFi will not work after install on laptop

@ Johnd2117, If you are still trying to get your old laptop to load the b43 driver instead of the wl driver, check this : Look in '/etc/modprobe.d/' for a file 'broadcom-sta-dkms.conf'. This file often blacklists the b43 and b44 drivers as they conflict with the 'wl' driver. Blacklist the 'wl' drive...
by dgordon42
Tue Aug 21, 2018 4:44 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: ttyAMA0 Serial on Rasbian Jessie @RPi B+
Replies: 7
Views: 10375

Re: ttyAMA0 Serial on Rasbian Jessie @RPi B+

gangwar wrote:Why am I not receiving the test_string?
I would need to know your Pi model, your OS, your Python version, your wiring, and see the script you are running before I could even guess.

Dave.
by dgordon42
Mon Jul 09, 2018 8:53 pm
Forum: Beginners
Topic: Stretch, numlockx: where is the file /etc/kbd/config ?
Replies: 2
Views: 261

Re: Stretch, numlockx: where is the file /etc/kbd/config ?

The file '/etc/kbd/config' does not exist by default in Stretch, as you have found out. I'm guessing that you want NumLock on at boot up to the CLI. I managed it by writing a bash script that runs at boot, based on this stackexchange question As for 'numlockx', simply installing it with 'apt-get' se...
by dgordon42
Tue May 15, 2018 9:53 pm
Forum: General discussion
Topic: Pi 3 Serial Issues
Replies: 30
Views: 43328

Re: Pi 3 Serial Issues

@marciokoko, Nice try, but no. The Pi uses one of it's serial ports to communicate with the Bluetooth Controller chip. It sends and receives low level data and instructions to/from the chip. Unfortunately, you can't just fire data at the chip and expect it to communicate it to another device over Bl...
by dgordon42
Tue May 01, 2018 1:19 pm
Forum: Troubleshooting
Topic: RPi 3 UART for RS232
Replies: 9
Views: 9508

Re: RPi 3 UART for RS232

There is no problem using both Bluetooth and the Serial Port simultaneously on the model 3, 3+, or Zero W RaspberryPi. Ensure that you do not have the phrase "console=serial0,115200" anywhere in your '/boot/cmdline.txt' file. Ensure that you do have the line "enable_uart=1" in your '/boot/config.txt...
by dgordon42
Wed Apr 11, 2018 5:27 pm
Forum: Python
Topic: Need help using serial port - RPi 3 Model B
Replies: 8
Views: 1194

Re: Need help using serial port - RPi 3 Model B

The commands only need to be run once.
You can check the status of the 'hciuart' daemon with:

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systemctl status hciuart
It should report "disabled" if the commands ran successfully, and should be remembered over a reboot or power cycle.

Dave.
by dgordon42
Wed Apr 11, 2018 3:14 pm
Forum: Python
Topic: Need help using serial port - RPi 3 Model B
Replies: 8
Views: 1194

Re: Need help using serial port - RPi 3 Model B

@matteochini: You have used the DT Overlay "dtoverlay=pi3-disable-bt" in your '/boot/config.txt' file. When you use this overlay, you also need to run the commands: sudo systemctl stop hciuart sudo systemctl disable hciuart These commands prevent SystemD from attempting to use the UART to talk to th...
by dgordon42
Wed Apr 11, 2018 12:48 pm
Forum: Troubleshooting
Topic: UART port not working properly
Replies: 8
Views: 2012

Re: UART port not working properly

@syed.idris: First, what type of Arduino are you using? Most (but not all) of them work at 5V, the Pi's UART works at 3.3V, and sending it a 5V signal directly from an Arduino can destroy a Pi. while receiving data some times data getting loss or sometimes it is showing as "serial port /dev/serial0 ...
by dgordon42
Tue Apr 10, 2018 12:12 pm
Forum: Troubleshooting
Topic: Power LED on shutdown - Pi3
Replies: 14
Views: 9342

Re: Power LED on shutdown - Pi3

Red LED lights when the supplied 5V power is within specs. It goes out when the power supplied drops below about 4.6V, although the Pi may continue to operate. Note that the fact that the Red LED is on does not mean that the Pi is up and running, only that the power supply is good. Green LED normall...
by dgordon42
Wed Mar 21, 2018 5:18 pm
Forum: General discussion
Topic: HELP! - Why does my program not compile?!
Replies: 6
Views: 405

Re: HELP! - Why does my program not compile?!

as I have done code changes and its still running an old version of the code... It's also worth checking that the new file is correctly written to your SD card. Sometimes SD cards can go "read only", it's one of the first signs of SD card failure, and results in 'old' versions of files appearing, e...
by dgordon42
Mon Mar 12, 2018 11:40 am
Forum: Beginners
Topic: Headless setup: no keyboard, display or frustration
Replies: 50
Views: 280990

Re: Headless setup: no keyboard, display or frustration

@LordOfDucks:
The guide posted at the beginning of this thread was posted in April 2014, and is out of date.
You should have better luck using the current guide.

Hope this helps,
Dave.
by dgordon42
Fri Mar 02, 2018 10:12 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: i2c problem - two slaves with same address
Replies: 2
Views: 457

Re: i2c problem - two slaves with same address

The mlx90615 device stores it's I2c address in it's EEPROM, and so you can change it to allow multiple mlx90615 devices on a single I2c Bus.
Details on page 9 of the datasheet

Hope this helps,
Dave.
by dgordon42
Wed Feb 28, 2018 12:20 pm
Forum: Raspbian
Topic: avahi-deamon causing lockups when network down
Replies: 2
Views: 269

Re: avahi-deamon causing lockups when network down

There are reports of RaspberryPi's locking up running the latest WiFi firmware when reconnecting to a WiFi network.
More here

Hope this helps,
Dave.

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