Topic summary
TTL serial
Extracted from the Wikipedia article Transistor–transistor logic.
Serial signaling
TTL serial refers to single-endedserial communication using raw transistor voltage levels: "low" for 0 and "high" for 1. UART over TTL serial is a common debug interface for embedded devices. Handheld devices such as graphing calculators and NMEA 0183-compliantGPS receivers and fishfinders also commonly use UART with TTL. TTL serial is only a de facto standard: there are no strict electrical guidelines. Driver–receiver modules interface between TTL and longer-range serial standards: one example is the MAX232, which converts from and to RS-232.