The SRF08 is an evolutionary step up from the SRF04. It requires less power to operate, has a longer range (up to 6m) and it performs its own internal timing of the return echo.
The SRF08 is also fitted with an LDR to measure light levels.
Communication with the SRF08 is via the I2C bus that is available on many popular microcontroller's.
Voltage - 5v only required
Current - 15mA Typ. 3mA
Standby. Frequency - 40KHz
Range - 3cm - 6m.
Max Analogue Gain - Variable 94 to 1025 in 32 steps.
Connection - Standard I2C Bus.
Light Sensor - Front Facing light sensor.
Timing - Fully timed echo, freeing host controller of task.
Echo - Multiple echo - keeps looking after first echo.
Units - Range reported in uS, cm or inches.
Small Size - 43mm x 20mm x 17mm height.