More fun with RDA1846 using the SA818V board

In this video I use the SA818 board which is a single board handheld with can transmit and receive on 2m (there is a 70cm version).

Documents for the SA818 are here

I have read that this board does not meet FCC spectral purity rules I do plan on putting a lowpass filter before transmitting which I haven't done yet. The board itself is available from various sellers - here for example

The code is very straighforward

but I would have gotten nowhere without this repo:

The 2560 connects to the SA818 via the Serial1 pins. I also have a simple audio amp after the SA818 based around an LM386

[zazugee]

I'm a bit confused by the ino file, while does it have RDA1846 lib when this sketch is dealing with the SA818 module? i thought you can't talk directly to the RDA when you're interfacing with the SA818?