Product Information

10 0x0A Set Maximum Analogue Gain to 133
11 0x0B Set Maximum Analogue Gain to 139
12 0x0C Set Maximum Analogue Gain to 145
13 0x0D Set Maximum Analogue Gain to 152
14 0x0E Set Maximum Analogue Gain to 159
15 0x0F Set Maximum Analogue Gain to 168
16 0x10 Set Maximum Analogue Gain to 177
17 0x11 Set Maximum Analogue Gain to 187
18 0x12 Set Maximum Analogue Gain to 199
19 0x13 Set Maximum Analogue Gain to 212
20 0x14 Set Maximum Analogue Gain to 227
21 0x15 Set Maximum Analogue Gain to 245
22 0x16 Set Maximum Analogue Gain to 265
23 0x17 Set Maximum Analogue Gain to 288
24 0x18 Set Maximum Analogue Gain to 317
25 0x19 Set Maximum Analogue Gain to 352
26 0x1A Set Maximum Analogue Gain to 395
27 0x1B Set Maximum Analogue Gain to 450
28 0x1C Set Maximum Analogue Gain to 524
29 0x1D Set Maximum Analogue Gain to 626
30 0x1E Set Maximum Analogue Gain to 777
31 0x1F Set Maximum Analogue Gain to 1025
Note that the relationship between the Gain Register setting and the actual gain is not a
linear one. Also there is no magic formula to say "use this gain setting with that range
setting". It depends on the size, shape and material of the object and what else is around
in the room. Try playing with different settings until you get the result you want. If you
appear to get false readings, it may be echo's from previous "pings", try going back to
firing the SRF08 every 65mS or longer (slower).
If you are in any doubt about the Range and Gain Registers, remember they are
automatically set by the SRF08 to their default values when it is powered-up. You can
ignore and forget about them and the SRF08 will work fine, detecting objects up to 6
metres away every 65mS or slower.
Light Sensor
The SRF08 has a light sensor on-board. A reading of the light intensity is made by the
SRF08 each time a ranging takes place in either Ranging or ANN Modes ( The A/D
conversion is actually done just before the "ping" whilst the +/- 10v generator is
stabilizing). The reading increases as the brightness increases, so you will get a maximum
value in bright light and minimum value in darkness. It should get close to 2-3 in
complete darkness and up to about 248 (0xF8) in bright light. The light intensity can be
read from the Light Sensor Register at location 1 at the same time that you are reading
the range data.