GE Attenuator / Mbed 2 deprecated VAM_DAX_RELIABILITY

update hcsr04.cpp by changing 20000 to 2000

Dependencies:   Stepper mbed SDFileSystem Ultrasonic PinDetect millis

Diff: .hgtags

Revision:
8:3f4d78017fd9
Parent:
1:4bda04eecf66