Puck.JS PCB design question, why a separate blue PCB from Raytao Corporation, what about it??

Hi!

All the pages that show photoes of the PuckJS, show that its hardware is made up of a grey PCB, that seemingly another blue PCB is mounted on, and on that blue PCB there's a metal cover writing "Raytao Corporation", and then separately an electronic component that writes "4 4" on it.

I have a question here:

So then, what PuckJS actually have done, is to source a NordicSemi nRF52832 module from Raytao Corporation?

For what reason, to delegate the consumer radio equipment certification process to Raytao Corporation?

Where can I read about Raytao Corporation?

What component is the "4 4" thing, a resistor?

Where is actually the antenna in the Puck JS, is it actually the metal cover that writes Raytao?

If a PuckJS is in clear sight, or under cotton textile, how many meters do you expect its Bluetooth signal to reach?

Thanks!

The "4 4" component is the on-board BLE antenna. But there is a second one... for NFC - you see them in the 'big pic' on http://www.espruino.com/Puck.js: multiple traces (2..3) along the edge of the PCB). For range you may read up on some long range tests here and here. You find more on the Web searching for 'nrf52840 range'.

I don't mean to speak for Gordon here, but regarding modules like that in general - It is common practice to use modules like that when building boards that include microcontrollers with builtin RF functionality or RF communication ICs, particularly for products being made in relatively small quantities. For example, the ESP8266, ESP32, RFM69, and many others are also normally done that way. By taking advantage of the expertise of companies specializing in RF design and using these standardized modules, designers can reduce costs and implementation risk while streamlining the design process. Those raytac modules are used in many products, not just the puck.js - it's an off-the-shelf module.

@DrAzzy hit the nail on the head here. The module manufacturers can get the RF design totally sorted, but also they can get all the different certifications for their modules.

If I were to try and get all the certifications myself it would cost tens of thousands of dollars. Not only that, but to put everything on the board myself I'd need:

• The microcontroller
  
• A selection of different capacitors and inductors for tuning
  
• A high speed oscillator
  
• A ceramic aerial
  
  

at minimum... The cost of all those parts in ~5000 qty actually adds up to the same or more than an individual module costs!