In our company, we are going to deliver a new product which will be used for mass notification, so it is an embedded software project and we are going to use the SCRUM as a framework for the product.
We have started to write down the product backlog. Based on what I understood the product backlog should reflect a business value for each item. The nature of embedded software is that it has a lot of technical details that will consume a large amount of time to create drivers for microcontrollers, like the SPI, UART, ethernet, WIFI, so on.
for example the System is sounding by playing message for notification, so it is pretty obvious that playing a message is a business value but to achieve this goal i have to write down the -requirements which are what also not how - for many drivers like the SPI, MP3 decoder chip driver, SD card driver and finally the FAT, so all of the previous drivers have requirements that should be written in the product backlog, such that the requirements started with a one business value requirement while it has a lot of technical sub-requirements.
These don't reflect a business value for the client; can someone tell me how am I going to create my product backlog?