Everything I know about the LC12S 2.4ghz "Transparent Uart"

I did a project a long time ago involving LED string lights, and in 2011 there were no good solutions for short range communications in a small enough package to fit in my design, so I used the FSK transceiver that I cannobalized out of the original hardware. This radio turned out way too unreliable to keep multiple processors in exact sync. The Sparkfun 300/400 Mhz units were just too big to fit.

Then along comes the LC12S, which is as cheap as $.75 each on eBay, Aliexpress, etc., so I ordered a handful to see if they'd work. After a few months, they showed up, but I could find only one website that discussed them (in English, at least) along with the Chinese datasheet.

My application requires a single transmitter broadcasting instructions to many receivers, and there is absolutely no mention as to whether that might work. So I breadboarded the transmitter, and working from the one website I had found, in addition to the seller's eBay site, nothing worked.

I use the PIC family of processors, mainly because I'm a dinosaur and cannot manage to learn modern languages, and PIC assembly language is in my wheelhouse. Everything I discuss should apply to whatever tech you might use (probably Arduino).

First mission was to translate the datasheet. I couldn't manage to find a tool to translate it in one fell swoop, so I just copied and pasted each short phrase of Kanji into Google Translate, and created a parallel English version. The resulting datasheet is here. The schematic on the wiring is where I went wrong, as the SET pin is only low when configuring the chip, while the datasheet shows it 'hard-wired' to ground.

• The SET pin is active LOW, so leave it unconnected if you're happy with the default settings.
• The DEFAULT settings are 9600baud and I haven't any good way to find the default power or channel settings, but all devices power up to the same values.
• The serial datalines are upside down, meaning the idle level is low and the leading ZERO is high.
• The BLUE LED appears to flicker with each transaction (there's at least one place where it claims it's an indication of the SET process, but that is false)
• One transmitter will broadcast to any number of receivers using default values. I was concernted that competing module IDs might screw up any handshaking going on with the 2.4ghz protocol.