There are always tradeoffs between Non Recurring Engineering (NRE, or product development costs) and Costs of Goods Sold (COGS, or the cost of the final product). The balance between the two depends on the project. Simple products will require lower COGS. However, never forget about NRE costs. It is possible for you to increase COGS slightly and save a lot of money on NRE. One example of this is an embedded project requiring UART. Assuming your microcontroller or design has no UART capability, you can go either the software or the hardware route. Most will go the software route. Why? obviously because software is cheap (the most erroneous assumption by some).

When you look at software, development is very expensive. Sure, you can bit bang UART and it will work, but to get it to work reliably will require code design, development and debugging. For just a little added cost to COGS (the price of the final product), you can save yourself major headaches, not to mention that you won’t be burdening your microcontroller with handling UART itself.

If you don’t believe it, consider that IBM’s own analysis of hundreds of software projects finds that software development does not scale linearly with complexity. Simpler software costs less.

Nonetheless, there are cases where hardware won’t do. This is especially true when upgrades will be required. UART is standard and won’t require upgrades, but a proprietary algorithm that’s in flux will change.