Solution #1
Problem
I often need to move from room to room while working on something and I like the sound to follow me. I could do this with my Alexa will not reliably reach all corners of my home. I understand that there are Wi-Fi speakers at $200+ EACH that will allow me to do this, but it just wasn’t worth that much to me.
Solution
I considered a couple of wireless solutions. I tried this first: Radio Transmission
At $6 for a radio transmitter and 2 old FM radios and one multiband portable radio, $8, I had a working solution. The device functions with USB power and a 3.5mm audio cable, into the board, out from the audio source.
How it’s made
Components
- FM Transmitter boards
- USB micro cable
- 3mm audio cable
- small antenna wire
- 3D printed case
- FM radios
- Optional -USB power block for portability
I purchased the FM transmitter boards, 2 for $12. I was lucky enough to find printable case for this board on the Thingiverse website. I soldered an antenna onto the board. I wasn’t sure how long to make it so I just made it about 3 feet. I fitted the works into the 3D printed case I had printed. Next I connected the USB mini cable and a 3mm audio cable into the audio in port. The USB cable provided power, but when connected to the USB port of my computer, the cable provided power AND audio out. In other words, I didn’t need the 3mm audio cable. When using other sources of audio, such as my stereo, the system needs both the USB and 3mm cables.
Next I had to find a radio frequency with little interference for broadcasting. I found that information on the site https://radio-locator.com/. I found the perfect frequency and placed FM radios around my home. Transmission was flawless and no lag in the audio.
I added a USB power block so that I could move my transmitter easily from place to place. Instead of cutting my very long antenna, I decided to wrap it around an empty toilet paper roll and cover it with contact paper. It made the system more portable because the antenna was no longer getting tangled up.
