[My aim is to simply send a single character or short string (with one of the various apps available), parse that information, and then toggle the digital output pin]

Afternoon everyone,

First off, my hardware setup:
A TinyDuino stack consisting of a processor board, USB Programmer, Proto board where I plan to connect a digital IC switch and lastly, the item this post is about, the Bluetooth LE shield (note: it's the new ST edition, not the discontinued Nordic one.)

I started out using the UART pass through example sketch provided on TinyCircuit's BT shield's info page. Works like a charm, passing information from an App (tried nRF UART v2.0 as recommended, Bluefruit LE, BLE Scanner and nRF Toolkit, all without any issues (on Android)). I can see the on board LED flashing when information is passed through and it shows the information on both the phone and serial terminal.

The second alternative I tried was to create a peripheral device using: https://github.com/sandeepmistry/arduino-BLEPeripheral
Takes up more space but you don't need any other 3rd party application to actually write the necessary behaviors. I tinkered with this but I cannot even get the BT module to broadcast anything / boot up.

As a third option, I tried interfacing with the Blynk system without any success (and is a bit overkill for what I want to do).

My aim is to simply send a single character or short string (with one of the various apps available), parse that information, and then toggle the digital output pin (can by any one not used by the BT module). I also had a look at TinyCircuit's smart watch code, on how the first character of the received string is checked, and a resulting function is performed, e.g., if string[0] == "t" -> update time. This approach, which is based on the older Nordic chip, doesn't seem to translate for the new chip if I try and adapt the code in a similar way. If you look at the newer tutorial page for the ST edition BT chip (which I am using), it was uploaded only 6 weeks ago. Hence my frustration is getting any working examples of interfacing with the new ST edition chip that is still quite a new product; any Instructable page or example from TinyCircuits is based on the Nordic chip edition (had a look at the hovercraft/boat example as well). 

I'm not exactly sure where to go from here or other possible ideas that can get my idea off the ground? Or I may be missing something where a simple sketch do the trick, which the more experienced members may be willing to assist me with?

Just a note, I am using this for my Master's dissertation project, and will reference any code accordingly. I am currently a post-graduate student at the Department of Civil Engineering at the University of Pretoria, South Africa, researching railway instrumentation for heavy haul freight. Only recently started tinkering around with Arduino but have read up on it extensively over the years, and I'm busy brushing up my knowledge on everything Bluetooth related at this stage.

Thank you in advance.

Kind regards,

Andre Broekman