Currently the primary risks are:
- Not being able to get the gigabit ethernet working. Managing this mainly by addressing it first,as it’s likely to be one of the most challenging parts of the project. If we’re unable to get it working, it’s best to know soon so we can switch to another interface as soon as possible. Current primary contingency plans are:
- Use a Zynq board. The Zynq chip has a built-in gigabit MAC, and, many reference designs using it. This moves the complexity from this to setting up the Zynq itself, though that will most likely use existing tools from the vendor.
- Use a USB interface. Either a fast micro controller with a USB interface such as the Teensy 4.0, or one of several development boards specifically designed for simple, high-speed USB interfaces, such as the CYUSB3KIT.
- Use an off-the-shelf board that already has an working example written for it, such as the Mimas A7 from Numato.
- Some aspect of the microphones renders then unsuitable for this project. We are managing this risk, again, by tackling it early. We have already ordered some sample microphones from Digikey and rigged up a testing board in order to run some basic tests and get some hands-on experience with PDM, since none of us have ever used it.
The overall design is unchanged from the previous update.