We do not have any sample code for a host MCU but in place of that, we have a clientcontrol.exe to emulate the host, and also to illustrate the working of the app. We also have a list of commands that puart-control application uses, inside the pdf doc.
The project is on hold while I research a few options. If I use puart_control then it looks like we'll have to do some significant protocol analysis to figure out the right sequence of commands to use.
One thing that would be helpful would be to document example message sequences between the host and the BCM20737 running puart_control. That way I could compare our message sequences with the example to be sure that we're headed in the right direction.