I have done this before a few years ago, for another Pi SCPI instrument: a programmable LAB 8 channel switcher. The screen captures in this post show that the services are executed by root, but if you follow the instructions, it 'll be the pi user that runs them.

Prerequisites

You should have built the two binaries for this project.

• daqhats_scpi_socket
• daqhats_service

These binaries should be placed in /home/pi/bin, and made executable (chmod +x <binary_name>). If you place them in another location, amend the scripts below.

Start and Stop Shell Scripts

I've created a startup and a shutdown shell script in that same /home/pi/bin directory, and made them executable (again using chmod +x <shell_script_name>).

daqhats_start.sh

#!/bin/bash
echo "start daqhats instrument service. Wait 5 seconds to complete ..."
/home/pi/bin/daqhats_service 2501 2502 0 &
sleep 5
echo "start daqhats scpi service."
/home/pi/bin/daqhats_scpi_socket 2500 2501 &
echo "start sequence completed"

daqhats_stop.sh

#!/bin/bash
killall -9 "/home/pi/bin/daqhats_scpi_socket"
killall -9 "/home/pi/bin/daqhats_service"

These scripts take care that the right order is used to start and terminate both executables. There's a 5 second sleep to allow the instrument service's binary to start its socket listening thread. Both scripts will be invoked by the service handler to start and stop the daemon.

Service Script

Now the core of this post: creating that Linux service that starts up at boot, and can be restarted by the user. I've used the Raspberry Pi OS' networking.service as inspiration, and this website for the instructions: https://www.dexterindustries.com/howto/run-a-program-on-your-raspberry-pi-at-startup/

Create a new service wrapper daqhats.service in the same directory.

[Unit]
Description=daqhats Service
DefaultDependencies=no
Requires=ifupdown-pre.service
Wants=network.target
After=local-fs.target network-pre.target apparmor.service systemd-sysctl.service systemd-modules-load.service ifupdown-pre.service network.target
Before=shutdown.target
Conflicts=shutdown.target
[Install]
WantedBy=multi-user.target
WantedBy=network-online.target
[Service]
Type=oneshot
#EnvironmentFile=-/etc/default/networking
ExecStart=/home/pi/bin/daqhats_start.sh
ExecStop=/home/pi/bin/daqhats_stop.sh
RemainAfterExit=true
TimeoutStartSec=5min
User=pi

Create a symbolic link for systemd:

sudo chmod  644 ./daqhats.service
sudo ln -s /home/pi/bin/daqhats.service /lib/systemd/system/daqhats.service

Then, tell systemd that there's a new configuration and tell it to enable the service:

sudo systemctl daemon-reload
sudo systemctl enable daqhats.service

If you reboot, the raspberry will start with the daqhats Service running.

Check:

Managing the Service

You can use the usual systemd commands to verify, stop and start the daemon.

sudo systemctl status daqhats.service
sudo systemctl stop daqhats.service
sudo systemctl start daqhats.service
sudo systemctl restart daqhats.service

Link to all posts.