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SF30
Accelerated rangefinder
6. Communicating with the serial port
The serial port is used to transmit distance readings to an embedded host processor such as the flight controller in a UAV. The
hardware interface uses 3.3 V logic levels and can be connected directly to any similar, compatible interface. The serial port
protocol should be set to 8 data bits, 1 stop bit and no parity or handshaking (8N1).
Distances are output as a single, binary coded byte when the "2: Snapshot resolution" is set to 1 m and as two binary coded bytes at
all other resolutions.
Snapshot resolution
< 1 m
Setting
@ 1.00 m
@ 0.50 m
3: Serial port
@ 0.25 m
update rate
@ 0.03 m
@ Filter
4: Serial port baud rate
The "3: Serial port update rate" setting allows the output rate of the serial port to be set to any value within the limits imposed by
the snapshot resolution. Values will be rounded in order to give whole number divisors of 36633 and limited automatically if they are
too high for the resolution selected.
The "4: Serial port baud rate" selection toggles through all the standard baud rates from 9600 to 921600. If the baud rate is set too
low, there won't be enough time for the data to complete a transmission before the next result is ready. A warning notice is given if
this situation occurs. Both the transmitted data and any received commands are at the same baud rate.
SF30 Accelerated laser rangefinder - Product Manual - Revision 4
Product manual
Figure 6 :: Serial interface connections
Data format
1 m
Byte
Byte_L,Byte_H
Values
1 ... 36633 / sec
Sets the rate at which new results are output from the serial port when it
is selected using "1. Active data port".
1 ... 18316 / sec
The actual value may be lower than the entered value depending on the
1 ... 9158 / sec
setting "2: Snapshot resolution".
1 ... 1144 / sec
Only whole number fractions of 36633 will give an exact match between
the entered and actual values.
1 ... 1144 / sec
Selects the baud rate for the serial port. If the "3. Serial port update
9600 ... 921600
rate" setting is too high for the selected baud rate then a warning notice
will be displayed.
Conversion to distance in meters
Distance = Byte
Distance = Byte_H + Byte_L / 256
Description
8
of
15
© LightWare Optoelectronics (Pty) Ltd, 2015
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