This application note describes the operation of a general- purpose, microcontroller-based Serial Port Interface (SPI) boot circuit. This is a low cost solution for users who need to modify some of ...

A PC’s serial port provides signal lines that you can use to read voltage levels of digital circuits. You can use the port to test digital TTL (transistor-to-transistor-logic)-level circuits. You just ...

[Mike Lu] likes to add serial ports to his routers to use for debugging but he didn’t want to drill holes in his new RT-N12. After a bit of head-scratching he thought about repurposing the four unused ...