Review on 🔊 HiLetgo 3pcs M18 Bluetooth MP3 Audio Receiver Board BLT 4.2 Lossless Decoder Wireless Stereo Sound Module by Damian Grotting

First of all I'd like to point out that I've been trying a lot of Bluetooth modules lately to add an unobtrusive Bluetooth audio pairing to some old (1980's) radios. But most importantly, these boards have the most pleasing sound indication of both ready to pair and successful pairing. That's not a human voice. It's not incredibly loud. It's beautiful and subtle. One of the main reasons I wanted this board to be able to display multimedia buttons. This is a really fun approach (in my opinion) with a single "KEY" pin that gives different results when grounded with different resistor values. This works very well, although you may have to dig around to find some of the resistors mentioned (although you can also put resistors in series to get the same result, i.e. 30kΩ + 3kΩ = 33kΩ). But don't forget to order resistors if you don't have the right ones and want to use the button function! First I tried to use pin headers and pluggable cables with this board. Instructions elsewhere on the internet are very clear that the wires are not to be joined, but welded (soldered) - in particular, the ground wire must be strong and short. This is to reduce ground isolation noise, which I've definitely experienced. This can be alleviated by soldering everything or placing a B0505S-1W between the power supply and this unit to isolate the noise. perhaps rather than sharing a borrowed component from another device. In my case I plugged 120V AC directly into the radio and hooked it up to cheap AC/DC converters (like a USB phone wall charger) to provide a stable 5V with no signal interference. And having buttons is great. There's even an indicator of when you've maxed the volume (for what it's worth, it starts at max volume, and since it's not boosted, that's perfect). The volume that can be changed here is independent of the volume of your Bluetooth device (phone). Either way, as the name suggests, if you know what you're doing or want to learn a little, these are great boards for the money. And they're the size of a postage stamp, so you can add them to almost any project or existing stereo/radio.