I recommend to use Python 3.x since Python 2.x is deprecated!
The python3-dev apk package provides /usr/bin/python3-config, so you’ll have to symlink that to /usr/bin/python-config:
apk update apk add python3-dev ln -sf /usr/bin/python3-config /usr/bin/python-config
Just install python2-dev, which installs /usr/bin/python-config
apk update apk add python2-dev
DTMF – also called tone dialling – is when a phone number is being dialled by tones at a specific frequency. Each number key on the phone is assigned a combination of two specific tones that are played when the key is being pressed.
DTMF is a newer version of dialing over analog lines, compared to the older pulse dialing method.
DTMF playback controls, if your phone plays the characteristic tone for each.
If DTMF playback is enabled, every time you press a number key on your phone, you will hear the characteristic tone for that key.
If DTMF playback is disabled, you will not hear a DTMF tone while pressing the number keys on your phone.
The OpenStage 40 SIP phone supports SIP port configuration using
Admin -> Network -> Port settings
In order to change the SIP port for chan_pjsip from the default port 5060 to a custom value first go to Settings => Asterisk SIP Settings
Then go to the SIP settings [chan_pjsip] tab:
Now scroll down to the bottom of the page and look for
Change it to the desired port, e.g. 15060
click Submit on the bottom right
After that, don’t forget to click Apply Config on the top right
You also need to Restart Asterisk after the change.
You can download the Connector_PCBEdge library from the KiCad website and use the footprints from there for your PCI express card. You can use one of these footprints:
When trying to login using WPA-EAP or 802.1X using the RADIUS protocol for authentication, you see an error message like
(235) Login incorrect (eap_peap: TLS Alert read:fatal:access denied): [uli/<via Auth-Type = eap>] (from client APs port 0 cli 98-55-2B-A9-76-B9)
The issue in my case was that the CA certificate was not valid any more. Go to
Services => FreeRADIUS => EAP
and scroll down to Certificates for TLS
You need to choose correct, valid certificates for both the SSL CA Certificate and the SSL Server Certificate. The CA must be the CA that issued the server certificate: I recommend using a Let’s Encrypt certificate – if you do, be sure to select the correct Let’s Encrypt CA here!
My specific issue was that I had selected an old (expired) CA as SSL CA Certificate which caused some clients (mostly Windows) to fail certificate validation while other clients that ignored the CA certificate were able to connect properly.
When trying to install a FreePBX 15 module like Asterisk REST Interface Users you see the error message
The Module Named "manager" is required.
but you can’t find the manager module in the module list
As you can see in module.xml in manager’s GitHub repository (which you can find easily by just googling FreePBX manager), the module is called
Asterisk API
Note that you can just click on the The Module Named "arimanager" is required. message if you disable your AdBlocker.
When trying to install a FreePBX 15 module like Asterisk Info you see the error message
The Module Named "arimanager" is required.
but you can’t find the arimanager module in the list of available modules.
As you can see in module.xml in arimanager’s GitHub repository (which you can find easily by just googling arimanager), the module is called
Asterisk REST Interface Users
In order to install it, you also need the manager module which is called
Asterisk API
Note that you can just click on the The Module Named "arimanager" is required. message if you disable your AdBlocker.
When trying to install a package using rpm-ostree, you see an error message like
error: Transaction in progress: deploy --lock-finalization revision=5040eaabed46962a07b1e918ba5afa1502e1f898bf958673519cd83e986c228f --disallow-downgrade
The error message means that currently there’s an rpm-ostree operating in progress and you need to wait for it to finish.
In order to see which process is running, use
ps aux | grep rpm
[[email protected] uli]# ps aux | grep rpm root 730 41.2 1.7 1218036 34568 ? Ssl 18:41 0:30 /usr/bin/rpm-ostree start-daemon zincati 1896 0.0 0.8 481172 17324 ? Sl 18:41 0:00 rpm-ostree deploy --lock-finalization revision=5040eaabed46962a07b1e918ba5afa1502e1f898bf958673519cd83e986c228f --disallow-downgrade root 3223 0.0 0.0 221452 832 pts/0 S+ 18:42 0:00 grep --color=auto rpm
As you can see in the second line:
zincati 1896 0.0 0.8 481172 17324 ? Sl 18:41 0:00 rpm-ostree deploy --lock-finalization revision=5040eaabed46962a07b1e918ba5afa1502e1f898bf958673519cd83e986c228f --disallow-downgrade
the user zincati is currently running rpm-ostree on my system. zincati is the Fedora CoreOS auto-updater – in other words, an automatic system update is currently running on CoreOS.
This minimal example shows how to create a wifi access point on the ESP32 using the Arduino framework on PlatformIO.
#include <Arduino.h>
#include <WiFi.h>
void setup() {
WiFi.softAP("MyWifiName", "MyWifiPassword");
}
void loop() {
// put your main code here, to run repeatedly:
}As you can see, it’s really simple. Just call
WiFi.softAP("MyWifiName", "MyWifiPassword");and the WiFi library will take care of the rest.
You can use the ESP32Ping library in order to easily ping the current gateway IP:
if(Ping.ping(WiFi.gatewayIP(), 1)) { // 1: Just one ping
// TODO What to do on ping succes
// Example: Print response time
Serial.print(Ping.averageTime()); // Unit: ms
Serial.println(" ms");
} else {
// TODO What to do if ping failed?
}#include <Arduino.h>
#include <WiFi.h>
#include <ESP32Ping.h>
void waitForWiFiConnectOrReboot(bool printOnSerial=true) {
uint32_t notConnectedCounter = 0;
while (WiFi.status() != WL_CONNECTED) {
delay(100);
if(printOnSerial) {
Serial.println("Wifi connecting...");
}
notConnectedCounter++;
if(notConnectedCounter > 50) { // Reset board if not connected after 5s
if(printOnSerial) {
Serial.println("Resetting due to Wifi not connecting...");
}
ESP.restart();
}
}
if(printOnSerial) {
// Print wifi IP addess
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
}
#define LED_BUILTIN 2
void setup() {
Serial.begin(115200);
WiFi.begin("MyWifiSSID", "MyWifiPassword");
// Wait for wifi to be connected
waitForWiFiConnectOrReboot();
// Initialize LED
pinMode(LED_BUILTIN,OUTPUT);
}
void loop() {
if(Ping.ping(WiFi.gatewayIP())) {
digitalWrite(LED_BUILTIN,HIGH);
Serial.print(Ping.averageTime());
Serial.println(" ms");
} else {
digitalWrite(LED_BUILTIN, LOW);
Serial.println("Error :(");
}
}6.12 ms 5.12 ms 5.11 ms 5.16 ms 4.95 ms 4.88 ms 4.84 ms 7.67 ms 5.01 ms 4.87 ms 4.81 ms 4.80 ms 4.85 ms 5.08 ms 5.76 ms 4.54 ms 5.12 ms 2.77 ms 4.88 ms 4.84 ms 6.07 ms 5.08 ms 4.91 ms 6.04 ms 4.88 ms 4.98 ms 6.43 ms 8.18 ms 4.93 ms 5.17 ms 4.97 ms 5.46 ms 5.88 ms 4.78 ms 4.88 ms 6.03 ms 4.84 ms 5.70 ms 5.94 ms 7.25 ms 5.07 ms 4.78 ms 5.51 ms 4.99 ms 5.04 ms 4.79 ms 4.94 ms 4.81 ms 5.97 ms 5.85 ms 4.83 ms 4.80 ms 4.80 ms 6.29 ms 4.99 ms 5.04 ms 9.21 ms 5.20 ms 6.05 ms 6.14 ms 5.03 ms 4.90 ms 7.22 ms 5.06 ms 4.94 ms 9.03 ms 5.13 ms 11.97 ms 6.32 ms 6.12 ms 4.92 ms 4.92 ms 6.01 ms 4.96 ms 4.98 ms 4.94 ms 6.08 ms 6.11 ms 4.93 ms 5.05 ms 5.78 ms 4.47 ms 6.28 ms 5.02 ms 5.13 ms 5.11 ms 5.19 ms 8.89 ms 5.76 ms 5.18 ms 8.08 ms 4.97 ms 4.89 ms 4.70 ms 5.40 ms 7.46 ms 5.09 ms 4.95 ms 4.96 ms 5.01 ms 5.01 ms 4.89 ms 6.22 ms 6.76 ms 6.92 ms 6.10 ms 9.61 ms 5.29 ms 6.13 ms 5.15 ms 5.02 ms 5.03 ms 5.01 ms 6.13 ms 4.78 ms 3.90 ms 6.27 ms 8.07 ms 5.94 ms 4.50 ms 6.13 ms 4.99 ms 6.07 ms 4.80 ms 4.84 ms 4.95 ms 4.95 ms 6.78 ms 4.88 ms
When trying to start jupyter hub, you see this error message:
[email protected]:~$ jupyter hub Traceback (most recent call last): File "/usr/local/bin/jupyter", line 8, in <module> sys.exit(main()) File "/usr/local/lib/python3.8/dist-packages/jupyter_core/command.py", line 285, in main command = _jupyter_abspath(subcommand) File "/usr/local/lib/python3.8/dist-packages/jupyter_core/command.py", line 124, in _jupyter_abspath raise Exception( Exception: Jupyter command `jupyter-hub` not found.
Remove the space between jupyter and hub. Instead of
jupyter hub
run
jupyterhub
[email protected] $ jupyterhub [I 2021-06-19 02:37:12.766 JupyterHub app:2463] Running JupyterHub version 1.4.1 [I 2021-06-19 02:37:12.766 JupyterHub app:2493] Using Authenticator: jupyterhub.auth.PAMAuthenticator-1.4.1 [I 2021-06-19 02:37:12.766 JupyterHub app:2493] Using Spawner: jupyterhub.spawner.LocalProcessSpawner-1.4.1 [I 2021-06-19 02:37:12.766 JupyterHub app:2493] Using Proxy: jupyterhub.proxy.ConfigurableHTTPProxy-1.4.1 [I 2021-06-19 02:37:12.773 JupyterHub app:1534] Loading cookie_secret from /home/uli/dev/jupyterhub_cookie_secret [I 2021-06-19 02:37:12.788 JupyterHub proxy:497] Generating new CONFIGPROXY_AUTH_TOKEN [W 2021-06-19 02:37:12.789 JupyterHub app:1808] No admin users, admin interface will be unavailable. [W 2021-06-19 02:37:12.789 JupyterHub app:1809] Add any administrative users to `c.Authenticator.admin_users` in config. [I 2021-06-19 02:37:12.789 JupyterHub app:1838] Not using allowed_users. Any authenticated user will be allowed. [I 2021-06-19 02:37:12.823 JupyterHub app:2530] Initialized 0 spawners in 0.001 seconds [W 2021-06-19 02:37:12.825 JupyterHub proxy:699] Running JupyterHub without SSL. I hope there is SSL termination happening somewhere else... [I 2021-06-19 02:37:12.825 JupyterHub proxy:703] Starting proxy @ http://:8000 02:37:12.946 [ConfigProxy] info: Proxying http://*:8000 to (no default) 02:37:12.948 [ConfigProxy] info: Proxy API at http://127.0.0.1:8001/api/routes 02:37:12.981 [ConfigProxy] info: 200 GET /api/routes [I 2021-06-19 02:37:12.981 JupyterHub app:2778] Hub API listening on http://127.0.0.1:8081/hub/ 02:37:12.982 [ConfigProxy] info: 200 GET /api/routes [I 2021-06-19 02:37:12.983 JupyterHub proxy:347] Checking routes [I 2021-06-19 02:37:12.983 JupyterHub proxy:432] Adding route for Hub: / => http://127.0.0.1:8081 02:37:12.984 [ConfigProxy] info: Adding route / -> http://127.0.0.1:8081 02:37:12.985 [ConfigProxy] info: Route added / -> http://127.0.0.1:8081 02:37:12.986 [ConfigProxy] info: 201 POST /api/routes/ [I 2021-06-19 02:37:12.986 JupyterHub app:2853] JupyterHub is now running at http://:8000
The following script will install Jupyter Hub in single user mode (i.e. only a single Linux user can login to Jupyter Hub using the web interface).
First install Python & PIP, then NodeJS, then Jupyter Hub, then configurable-http-proxy :
curl -sL https://deb.nodesource.com/setup_14.x | sudo -E bash - sudo apt-get install -y nodejs python3-pip sudo pip3 install jupyterhub sudo npm i -g configurable-http-proxy
Run the following script using sudo!
#!/bin/bash
# This script installs and enables/starts the JupyterHub systemd service
export NAME=JupyterHub
# Create service file
cat >/etc/systemd/system/${NAME}.service <<EOF
[Unit]
Description=${NAME}
[Service]
Type=simple
ExecStart=/usr/bin/env jupyterhub --port=11569
User=root
Group=root
Restart=on-failure
RestartSec=5s
[Install]
WantedBy=multi-user.target
EOF
# Enable and start service
systemctl enable --now ${NAME}
This script will install a systemd service named JupyterHub autostart it on boot. It is running on port 11569 by default.
Note: This will only allow a single (preconfigured) user to login to Jupyter lab! See How to run Jupyter Hub (multi-user mode) using systemd on how to deploy Jupyter Hub in multi-user mode using systemd, which allows any Unix user to login!
The following script will install Jupyter Hub in single user mode (i.e. only a single Linux user can login to Jupyter Hub using the web interface).
First install Python & PIP, then NodeJS, then Jupyter Hub, then configurable-http-proxy :
curl -sL https://deb.nodesource.com/setup_14.x | sudo -E bash - sudo apt-get install -y nodejs python3-pip sudo pip3 install jupyterhub sudo npm i -g configurable-http-proxy
Run the following script as the user you want to be able to login! Do not run the script using sudo !
#!/bin/bash
# This script installs and enables/starts a systemd service
export NAME=JupyterHub-$USER
export GROUP=$(id -gn $USER)
# Create service file
sudo tee /etc/systemd/system/${NAME}.service <<EOF
[Unit]
Description=${NAME}
[Service]
Type=simple
ExecStart=/usr/bin/env jupyterhub
WorkingDirectory=$HOME
User=$USER
Group=$GROUP
Restart=on-failure
RestartSec=5s
[Install]
WantedBy=multi-user.target
EOF
# Enable and start service
systemctl enable --now ${NAME}
This script will install a systemd service named JupyterHub-$USER (where $USER is the current user, e.g. uli) and autostart it on boot.
If you run multiple services, you can run the script for each user and choose a unique port for each service by adding --port=7219 to the /usr/bin/env jupyter hub command, e.g.
ExecStart=/usr/bin/env jupyterhub --port=7192
Alternatively, you can run a single systemwide Jupyter Hub in multi-user mode where multiple users can log in.
When trying to start Jupyter Hub, you see an error message like
[E 2021-06-18 13:07:48.462 JupyterHub proxy:711] Failed to find proxy ['configurable-http-proxy']
The proxy can be installed with `npm install -g configurable-http-proxy`.To install `npm`, install nodejs which includes `npm`.If you see an `EACCES` error or permissions error, refer to the `npm` documentation on How To Prevent Permissions Errors.
[C 2021-06-18 13:07:48.462 JupyterHub app:2739] Failed to start proxy
Traceback (most recent call last):
File "/usr/local/lib/python3.8/dist-packages/jupyterhub/app.py", line 2737, in start
await self.proxy.start()
File "/usr/local/lib/python3.8/dist-packages/jupyterhub/proxy.py", line 707, in start
self.proxy_process = Popen(
File "/usr/lib/python3.8/subprocess.py", line 854, in __init__
self._execute_child(args, executable, preexec_fn, close_fds,
File "/usr/lib/python3.8/subprocess.py", line 1702, in _execute_child
raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'configurable-http-proxy'
As outlined in the Jupyter Hub installation docs, you need to install the configurable-http-proxy npm package in order for Jupyter to work:
sudo npm install -g configurable-http-proxy
In case you haven’t installed npm, see our article on How to install NodeJS 14.x LTS on Ubuntu in 1 minute or find the appropriate distribution for your OS on the NodeJS download page.
The default admin password is 123456.
The deployment pin for initial setup is 40001998
Calculate the minimum and maximum value of a resistor based on its temperature coefficient.
Too much power dissipation? You need to use a current sense amplifier ! See our Sense resistor / current shunt + current sense amplifier calculator !
Want to calculate the correct sense resistor value for your desired sense voltage? See Sense resistor / current shunt calculator
This calculator allows you to find out how much power your sense resistor will dissipate and how much voltage it will drop at a given current.
When logging into your CoreOS instance, you see this warning message:
############################################################################ WARNING: This system is using cgroups v1. For increased reliability it is strongly recommended to migrate this system and your workloads to use cgroups v2. For instructions on how to adjust kernel arguments to use cgroups v2, see: https://docs.fedoraproject.org/en-US/fedora-coreos/kernel-args/ To disable this warning, use: sudo systemctl disable coreos-check-cgroups.service ############################################################################
but when you look at https://docs.fedoraproject.org/en-US/fedora-coreos/kernel-args/ you only see an example of how to initialize a new CoreOS instance with Ignition files with cgroups v2.
In order to migrate your system to cgroups v2, run
sudo rpm-ostree kargs --delete=systemd.unified_cgroup_hierarchy
After that, you need to reboot your system in order for the changes to take effect:
sudo systemctl reboot
After the system has rebooted, the error should disappear.