«DiY» WeSwitch#

Switch Sockets via wired network Completed

The Challenge#

Enable switching of a power socket (basically an relais) remotely via wired network operated by a tech-savvy user.

Given / provided components:

../../_images/switchbox_with_cable_and_type_label.png

SwitchBox with cable and type label#

../../_images/RPI_4B_and_memory_card.png

Raspberry Pi 4B with memory card#

I coulnd’t find the operation manual online anymore, since I got it in paper form I scanned it: Operation Manual SwitchBox Relais-V1

Outcome#

Use command line tool pinctrl shipped with Raspberry Pi OS Lite (64-bit) to control remotely one or up to 26 Relais via ssh.

../../_images/bd_system_and_neighbors.svg

Usage#

The BCM pin numbers are to be used. See RPI Pinout.

Set-up passwordless login:

some_user@some_host:~$ ssh-copy-id weswitch@weswitch

Common commands:

1some_user@some_host:~$ ssh weswitch@weswitch "pinctrl 26"
226: op -- pd | hi // GPIO26 = output
3some_user@some_host:~$ ssh weswitch@weswitch "pinctrl 26 dl"
4some_user@some_host:~$ ssh weswitch@weswitch "pinctrl 26"
526: op -- pd | lo // GPIO26 = output
6some_user@some_host:~$ ssh weswitch@weswitch "pinctrl 26 dh"

Modify initial states#

Currently pins 19 and 26 are set to ON after reboot. All other pins are in default behavior which is OFF.

The initial state of each pin can be changed by modifying the file /boot/firmware/config.txt. The keyword dh needs to be replaced by dl:

For this edit the file /boot/firmware/config.txt (you need sudo rights):

1some_user@some_host:~$ ssh weswitch@weswitch "sudo vi /boot/firmware/config.txt"
2some_user@some_host:~$ ssh weswitch@weswitch "sudo reboot"

As default the GPIOs are OFF after reboot. Let’s change it as described in the RPI documentation:

Hint: Existing explicit settings you can change using sed to be quicker:

1some_user@some_host:~$ ssh weswitch@weswitch "sudo sed -i 's/\(gpio=19=op,\)dh/\1dl/' /boot/firmware/config.txt"
2some_user@some_host:~$ ssh weswitch@weswitch "sudo sed -i 's/\(gpio=26=op,\)dh/\1dl/' /boot/firmware/config.txt"
3some_user@some_host:~$ ssh weswitch@weswitch "sudo reboot"

Pin-out#

Pin-out and orientation of 40-pin header of RPI 4B. Source/credits to: https://toptechboy.com/understanding-raspberry-pi-4-gpio-pinouts/

../../_images/rpi_4b_pinout.png

RPI Pinout#

Making-Of#

«DiY» WePosture