433 RF Remote – Austin Fisk

Overview & Goals

I wanted a pocketable remote that could sleep most of the time, wake instantly, send a 433 MHz packet, and drop back into a low-power state on a coin cell. It also doubled as a crash course in PCB design, RF layout, and enclosure design.

Learn PCB design and layout for a real battery-powered product.
Hand place and solder SMD parts, then move to paste + stencil + hot air.
Debug wake-up sources, sleep behavior, and RF performance.
Design comfortable cases and iterate on the ergonomics.

Parts & BOM

The board combines the MCU, RF circuitry, 125 kHz section, buttons, and a coin cell holder. The full BOM came out to around $300 including prototyping.

Bill of materials spreadsheet — Bill of Materials for the 433 MHz Remote PCB.

Schematic

The remote’s PCB hosts the RF front end, MCU, 125 kHz interface for future features, and all user buttons. I wanted a single compact board that could slide into different cases.

PCB

The remote’s PCB hosts the RF front end, MCU, 125 kHz interface for future features, and all user buttons. I wanted a single compact board that could slide into different cases.

Assembled PCB front with antenna — Assembled PCB with the helical 433 MHz antenna mounted.

Early builds were fully hand-soldered; later ones used solder paste, a stencil, and hot air for more consistent joints and RF behavior.

Fixes

Low power mode can only be woken up from a signal coming from 3v being pulled down to ground. Had to move the antenna from its original placing. The hand soldering job wasn't working great for the RF.

433 MHz RF remote pull up fix — Schematic fix to utilize low power mode

Poor hand soldering — Hand soldering that left room for inprovement

Early builds were fully hand-soldered; later ones used solder paste, a stencil, and hot air for more consistent joints and RF behavior.

Imprived RF — The RF is finally looking good

RF Debugging & Fixes

The first revision taught me a lot about RF layout. Moving the antenna away from ground and power planes, improving solder joints, and cleaning up the layout dramatically improved range and reliability.

RF Lessons Learned

Antenna over continuous planes can hurt range and detune the coil.
Lead dress and connector geometry matter more than they look at 433 MHz.
Consistent solder reflow equals more consistent RF behavior across builds.

433 MHz RF Low power Board bring-up

Rectangular Remote Case

The first case version was a classic rectangular remote: easy to print, easy to hold, and a good playground for button spacing and board retention features.

Top view of remote 3D model with buttons — Initial 3D model used to test button spacing and overall size.

Tall remote shell 3D model — Refined case design with internal rails for the PCB.

Board inside 3D printed case, side view with antenna — Board and coil antenna installed in the first-generation case.

TouchTunes RF Remote

To give the remote a real job, I decoded the RF protocol used by TouchTunes jukebox remotes and mapped the buttons to volume control, play/pause, skip, and pin programming. The remote wakes from sleep on the first button press, then returns to sleep automatically after a timeout.

Remote in hand powering on from sleep — Waking the remote from sleep – LED indicates power-on.

Remote in hand volume up — Volume Up – mapped to one of the top buttons.

Remote in hand pause/play — Pause / Play control for the jukebox.

Remote in hand skip song — Skip Song while keeping the current volume area and pin.

Remote in hand volume area up — Volume Area Up – cycles through different zones (bar, patio, etc.).

Remote in hand volume area down — Volume Area Down – step backwards through the available areas.

When you select change your volume area, the LED will flash out which area is newly selected.

Remote in hand pin up fast — Pin Up – Fast: quickly scan through possible TouchTunes pins.

Remote in hand pin down fast — Pin Down – Fast: step backwards during pin search.

There are 256 different pins. Each juke box can have a different pin. Once you find your pin, the Volume Up, Volume Down, Pause/Play, and Skip song will use your selected pin. This sends a volume up signal with every chagne of the pin so that the user of the remote can verify when they have the correct pin. Most Touch Tunes work on Pin 0.

How to find the pin of your juke box: Starting at Pin 0, cycle up pins using Pin Up - Fast. Once you pass a pin that interacts with your juke box, you can go back over that pin with Pin Up/Down - Slow to set your remote to the correct Pin.

Remote in hand reset device — Reset – returns the volume area to Area 1 and the pin back to 00.

TouchTunes Behavior

Remote must be woken from sleep before use; auto-sleeps ~10 seconds after last press.
Volume Up/Down, Pause/Play, and Skip all respect the currently selected pin and area.
There are 256 possible pins; most TouchTunes units default to Pin 0, but the remote can scan quickly using Pin Up/Down – Fast, then refine using slower steps.

Turning the volume up & down in Area #3

Pausing the bar's music

Turning up the volume in Area #2

Incognito “Vape” Case

While testing the TouchTunes remote at a bar, the idea came up to disguise it as a vape. A couple of days of SolidWorks tutorials later, I had a vape-style case that fit the remote perfectly – and fooled a few friends who thought I’d picked up vaping.

Rendered 3D model of the vape-style case — Full 3D model of the vape-style enclosure with button layout.

Vape case body with internal rails — The real vape product I used as the reference for proportions.

Finished printed vape case front view — Printed vape case with the remote inside – front view with LED diffuser.

Top view showing antenna coil in nozzle — The 433 MHz coil antenna hides perfectly in the vape “nozzle.”

Back view of the finished vape case — Back of the case – looks like a normal vape sitting on a bar table.

Vapes usually have a heating coil in the nozzle, which lines up nicely with the RF antenna visually. The nozzle pops off to give easy access to the battery and PCB.

Status

The remote works reliably as a TouchTunes controller and as a general-purpose 433 MHz platform. The rectangular and vape-style cases both hold the board securely and feel good in hand, making this a solid base for future handheld RF projects.