I see many projects with RS232 ports for talking to a PC. They have a MAX232 chip to generate RS232 voltages to drive signals a few inches into an RS232-to-USB dongle, because modern PCs don't have RS232 ports. This is crazy, because you can buy serial TTL-to-USB cables for the same price as an RS232 dongle alone. This project shows how to ditch the MAX232 circuit. As a bonus, the cable can supply 5V at 100mA to power your project!