Building GHDL on Ubuntu 18.04

GHDL is an open-source simulator for the VHDL language. GHDL allows you to compile and execute your VHDL code directly in your PC. The latest stable release is version 0.36. Documentation and “getting started” can be found here.

To download the source code and switch to the right tag use following commands:

$ git clone https://github.com/ghdl/ghdl.git
$ git checkout tags/v0.36

Install some requirements using apt:

$ sudo apt install gnat libz-dev

Now you can configure, build and install the simulator:

$ ./configure --prefix=/usr/local/
$ make
$ sudo make install

Installing Redis on Debian 9

Redis is an in-memory key-value store known for its flexibility, performance, and wide language support.

Installation is very easy considering that it is provided by apt:

# apt install redis-server

After installation Redis will be running as a service. You can use these commands to check the status, or start and stop:

# service redis status
# service redis start
# service redis stop

Or the systemctl version:

# systemctl status redis
# systemctl start redis
# systemctl stop redis

TESTING YOUR INSTALLATION

Using the command “redis-cli” you get a command line prompt. The following commands will show you the basic functionality of your Redis server:

# redis-cli
127.0.0.1:6379> ping
PONG
127.0.0.1:6379> set test "Is it working?"
OK
127.0.0.1:6379> get test
"Is it working?"
127.0.0.1:6379> exit
#

Installing Mosquitto on Debian 9

MQTT or Message Queuing Telemetry Transport, is an ISO standard (ISO/IEC PRF 20922) publish-subscribe-based messaging protocol.

Mosquitto by Eclipse is an open source implementation of an MQTT message broker. It currently implements MQTT protocol versions 5.0, 3.1.1 and 3.1. It’s lightweight and suitable for use on all devices from low power single board computers to full servers.

Installation is very easy considering that it is provided by apt:

# apt install mosquitto

After installation Mosquitto should be running as a service. You can use these commands to check the status, or start and stop:

# service mosquitto status
# service mosquitto start
# service mosquitto stop

Or the systemctl version:

# systemctl status mosquitto
# systemctl start mosquitto
# systemctl stop mosquitto

Testing your installation

To test our new installation we need to install a few extra packages:

# apt install mosquitto-clients

To subscribe to topic1 subtopic2 we use the following command:

# mosquitto_sub -v -t "/topic1/subtopic1"

In an other console session you can then enter following command to publish a message to this subtopic:

# mosquitto_pub -m "test message" -t "/topic1/subtopic1"

If the message is received in your first session your MQTT installation is working as intended. By default mosquitto listens on all interface. To only allow traffic from localhost add “bind_address localhost” to “/etc/mosquitto/mosquitto.conf” and restart the service.