LED

The red LED is used to flash out a code for the I2C address on power-up (see below). It also gives a brief

flash during the "ping" whilst ranging.

Changing the SRF02 Address

To change the address of the SRF02 you must have only one sonar connected. Write the 3 sequence

commands in the correct order followed by the address. Example; to change the address of a sonar currently

at 0 (the default shipped address) to 5, write the following to address 0; (0xA0, 0xAA, 0xA5, 0x05 ). These

commands must be sent in the correct sequence to change the I2C address, additionally, No other command

may be issued in the middle of the sequence. The sequence must be sent as four separate commands to the

current address of the sonar. i.e. 0x00, 0xA0 then 0x00, 0xAA, then 0x00, 0xA5 and finally 0x00, 0x05.

When done, you should label the sonar with its new address, however if you do forget, just power it up

without sending any commands. The SRF02 will flash its address out on the LED. One long flash followed

by a number of shorter flashes indicating its address. The flashing is terminated immediately on sending a

command the SRF02.

Command

Action

Decimal

Hex

80

0x50

Real Ranging Mode - Result in inches

81

0x51

Real Ranging Mode - Result in centimeters

82

0x52

Real Ranging Mode - Result in micro-seconds

83

0x53

Real Ranging Mode - Result in inches, automatically Tx range back to

controller as soon as ranging is complete.

84

0x54

Real Ranging Mode - Result in centimeters, automatically Tx range back to

controller as soon as ranging is complete.

85

0x55

Real Ranging Mode - Result in micro-seconds, automatically Tx range back

to controller as soon as ranging is complete.

86

0x56

Fake Ranging Mode - Result in inches

87

0x57

Fake Ranging Mode - Result in centimeters

88

0x58

Fake Ranging Mode - Result in micro-seconds

89

0x59

Fake Ranging Mode - Result in inches, automatically Tx range back to

controller as soon as ranging is complete.

90

0x5A

Fake Ranging Mode - Result in centimeters, automatically Tx range back to

controller as soon as ranging is complete.

91

0x5B

Fake Ranging Mode - Result in micro-seconds, automatically Tx range

back to controller as soon as ranging is complete.

92

0x5C

Transmit an 8 cycle 40khz burst - no ranging takes place

93

0x5D

Get software version - sends a single byte back to the controller

94

0x5E

Get Range, returns two bytes (high byte first) from the most recent ranging.

95

0x5F

Get Minimum, returns two bytes (high byte first) of the closest range

measurable - see Autotune section

96

0x60

Force Autotune Restart - same as power-up. You can ignore this command.

160

0xA0

1st in sequence to change I2C address

165

0xA5

3rd in sequence to change I2C address

170

0xAA

2nd in sequence to change I2C address

Address

Long Flash Short flashes

Decimal

Hex

0

00

1

0

1

01

1

1

2

02

1

2