Testing USB serial relay compatibility with Mikrotik RouterOS - Fail

I've got some Amateur Radio projects in the pipeline that will require the ability to turn off the radio remotely in the event of a fault developing. This needs to be out-of-band and accessible to more than one "closedown-operator" so if the main operator isn't available, someone else can shut the station down.

The projects all require a computer of some sort, so I had an idea that I could use a USB serial relay to switch the power to the radios off, assuming they'd be easy to use and compatible with both standard form factor PCs as well as SBCs like Raspberry Pis.

I quickly realised this wouldn't be ideal as the situation might arise where the computer has crashed and left the radio transmitting, and it wouldn't be possible to switch off the relay, so I needed an alternative. As it happens I was also planning on including a Mikrotik router in these builds as they've gained the nickname "The Swiss Army Knife of Routers" and allow you to quickly setup tunnels and VPNs which are useful for remote access. Some models also have a USB port, and basic support for USB serial adapters, so I bought a few from AliExpress to test them out.

USB Serial Adapters


Flashing MMDVM on an STM32 Nucleo using Raspberry Pi OS 11 / Bullseye

5 years ago I wrote a blog post on Flashing MMDVM onto an STM32 Nucleo with OSX. Well, good news patient readers, I'm back with a new post, this time doing the flashing from Raspberry Pi OS 11 / Bullseye.