This stemmed from a review of a friend’s circuit design that used the UART in the project, but also called for an FTDI chip in order to reprogram via USB and a bootloader. Unlike the schematic ...

[Danko]’s minimal circuit is about as small as possible for the DIP version of the venerable 555 chip. The BOM is stripped to the bone: just the chip, three resistors, a capacitor, and an LED.