I need BLE connectivity in a product, so to save costs on FCC certification, Bluetooth SIG membership, etc. it will use a pre-certified module for this purpose.
Usually such modules work in one or multiple of the following ways:
- Controlled through an external interface (e.g. AT commands over UART)
- Programmable using some proprietary scripting language (e.g. Bluegiga modules)
- Fully user programmable
The first two approaches seem logical, the manufacturer of the module has very tight control over what can be done with the hardware (especially RF parameters, etc.).
The third approach is very appealing – most BLE chips already contain powerful microcontrollers, so it make sense to do all the processing on them. However I'm not sure whether one still gets the simplified FCC certification. I was under the impression that firmware is part of FCC testing too, especially since RF parameters (usually) can be changed significantly by software. However I wasn't able to find any warnings/clarifiactions about that in the datasheets/app notes/other docs. Could anyone clarify this a bit?
I'm mainly looking at nRF52 based and Cypress EZ-BLE modules.
Best Answer
It has been my experience that you would have to re-certify if you are replacing the firmware in the module.
Be aware that despite the pre-certified nature of certain modules that ultimately you or your company are responsible for meeting the legal requirements for emissions and immunity of the product as a whole. So even though a module may be pre-certified you still need to test your system with the module present.
The only place I know of where a pre-certified type module may have some decided advantages are as follows: