While revising almost everything for our show this year, I decided to more-permanently install our master FPP controller (Raspberry Pi 3B+) and FM transmitter. The controller lives on my desk most of the rest of the year because I use it to test new FPP versions, and I wanted to move it out of the way. I also might use it for other lighting projects during the off season. The FM transmitter was always awkward to keep outside because of its attached antenna, and the need to keep its PSU some distance away from it to cut down on any buzzing. It didn’t fit well in an ammo box, and I didn’t want to spend more money trying to get it sealed up against the weather. When outside- it’s transmit distance was way too far for my comfort level as-well.

So, I mounted them in a basement tool/storage room, near where they usually go outside. I used a scrap wood shelf mounted on top of the sill plate for the FM transmitter, which puts its antenna behind the outside wall, but above the foundation wall. This will reduce its transmit distance a bit, but still- it works great to the front of the house which is all I need.

At the edge and under the shelf- I added another piece of wood so I could mount a DIN rail. Have I mentioned that I LOVE DIN RAILS? To that- I mounted a Meanwell DIN rail PSU, along with a my FPP Master Raspberry Pi, using a DIN rail plate for it. As-usual, I also added a small voltage meter so I know it has good power.

Here are the PSU, RPi DIN mount, and DIN Rails I used:

Finally, the FM transmitter is controlled using a D1 Mini Relay that I mounted inside a “shallow” outlet box I had in stock. These have an extension that normally fits behind a wall that was the perfect size for the little D1 and relay shield. I fused the circuit to the 10A limit of the relay, although the transmitter hardly uses any power. I’m powering the D1 from the same PSU as the RPi. The FM transmitter’s power brick is mounted a couple of feet away, since it can cause interference with the transmitter. The transmitter doesn’t seem to be influenced by the Meanwell PSU or RPi, at least at the short distance they are from it.

So- I have my FPP Master running all the time now, and can toggle the FM transmitter on and off as part of my show playlists. I’m just running RPi audio to the transmitter for now. Frankly- I can’t tell the difference between it and the USB audio adapters everyone insists on using. I used one last year, but for some reason can’t get it to work this year.

Quick Update (Nov. 2021):
Probably due to all of the ductwork, plumbing, and electrical circuits near it- the D1 Mini would not connect to WIFI most of the time, so that part of the setup didn’t work. I swapped it out for a GPIO-driven relay connected directly to the RPi. This has worked flawlessly. You can toggle GPIOs easily within FPP via scripts, playlists, or even sequences since they are configured as outputs.

Update (Nov. 2022):
I ended up with an RPi 4, so upgraded the Show Runner (Master) so I could re-use the RPi 3B+ for another project. I also added an OLED display, and used some DIN rail terminals for the relay link just to clean up the install a bit. Here is a new pic:

The OLED is just nano-taped to the front of the PSU. The RPi 4 uses the same (excellent!) steel mounting plate as the 3B+. The same GPIO runs the FM Tuner relay. The only mildly annoying thing that I will eventually fix is the voltage display is in the opposite orientation of the OLED. Sometime in 2023 I will probably just flip the orientation of the OLED in FPP.