Question: When should I use an external MCU with PRoC-UI?
All variants of PRoC-UI (PRoC-TT, PRoC-CS, PRoC-USB, and PRoC-EMB) have an onboard MCU. Typically there is no need for you to use an external MCU in your design.
In some cases your design may require more general purpose I/Os (GPIOs) than available on the PRoC-UI parts. An example of a design like this is a keyboard with a built-in trackpad.In such cases PRoC-UI supports connection of an external MCU over SPI. In the case of the keyboard with built in trackpad, the external MCU can handle mechanical buttons while the PRoC-UI can handle the trackpad and radio functionality.
We recommend the enCoRe Low Voltage series of MCUs for use with PRoC-UI. To find out more about our enCoRe low voltage MCUs please click here