Messing About With NodeRed

 I'm still messing about with my ideas for QO-100 and I'm now thinking that I'm going to make a remote box of tricks that will be connected by ethernet to the house.

The main SDR will be the Adalm-Pluto which will give me the full duplex I need for TX on 2.4GHz and RX on 700 ish MHz.

Inside the box I would like to be able to monitor the health of the various power rails I'm going to need plus I would like to be able to switch a few things on and off.

I've started to look at NodeRed - a most excellent piece of software that can allow me to create a dashboard to do just about all the things I want. This can run on a Raspberry Pi in the remote box of tricks and get controlled by a dashboard from a web browser on the network elsewhere.

So far I have installed the software on a Pi5, tried a HID relay unit, which needed this jiggery pokery completed before it would work:

Linux Dependancies

For linux you will need to make sure you install some additional libraries. For debian and raspbian this should be done with the following: sudo apt-get install libudev-dev librtlsdr-dev libusb-1.0-0-dev libpthread-stubs0-dev git

You will also need to add udev rules. Create the following file /etc/udev/rules.d/50-hidrelay.rules. This allows node-red the permissions to commuincate with the device directly.

SUBSYSTEM=="input", GROUP="input", MODE="0666"
SUBSYSTEM=="usb", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="05df", MODE:="666", GROUP="plugdev"
KERNEL=="hidraw*", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="05df", MODE="0666", GROUP="plugdev"

I now have a simple flow graph in Node Red:

Which creates a simple dashboard with some buttons:

and these buttons, do indeed switch the relays on and off.

I've ordered some INA219 boards, these are voltage and current monitors that will interface to the Pi using I2C. There is a module for these in Node Red so should be able to create voltage monitoring OK with these devices.

More to follow!