Download What is PPS58-Nx PPS58-Nx Feature List Electrical

PPS58-Nx User Guide
What is PPS58-Nx
PPS58-Nx is a Pneumatic Pressure Sensor
designed for NXT. This can be used to
detect upto 58 PSI pressure in the Lego
pneumatics (or any other pneumatics)
system. Following sections provide
operation and specifications of sensor.
PPS58-Nx Feature List
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Uses I2C digital interface.
Measures pressure using solid-state sensor up to 10-bit
resolution.
Provides three different units of measure: PSI, kPA and millibar.
Is pre-calibrated and needs no calibration.
Electrical Connections
Connect to any port of NXT using the standard cable from NXT set.
Pneumatic Connections
PPS58-Nx is designed to be compatible with standard Lego
Pneumatic tubing. As such, if you want to use it with any other
pneumatics system or solenoid valve system, please use appropriate
adapter tubing.
I2C Bus address
Factory Default Address: 0x18.
Current Consumption
Average measured current profile is as follows:
Current Consumption
6.5mA
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Duration
Continuous
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Calibration
PPS58-Nx is pre-calibrated and does not require calibration.
Programming Techniques for reading
NXT-G:
Download the NXT-G block that’s available in the
NXT-G Blocks Repository at Mindsensor’s website at
following URL.
http://www.mindsensors.com/index.php?
module=documents&JAS_DocumentManager_op=viewDocument&JAS
_Document_id=190
RobotC:
API not available yet.
NXC:
Download the sample programs and library file available at following
location, and include the library file it in your program by #include
directive as:
#include “PPS58-lib.nxc”
Alternately, you can modify the sample programs to suite your needs.
http://www.mindsensors.com/index.php?
module=documents&JAS_DocumentManager_op=viewDocument&JAS
_Document_id=188
I2C Registers:
The PPS58-Nx appears as a set of registers as follows:
Register
0x41
0x42
Read
Currently configured unit of
measure, byte as follows:
‘p’: PSI
‘b’: millibar
‘k’: kPA
0x43
Absolute pressure value (two
bytes)
Gauge pressure value (two
bytes) (this is difference
between the reference
pressure and absolute
pressure).
Reference Pressure Value
0x45
0x47
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Write
Command Register
You could write the units
directly to this register,
however it is recommended to
use respective Command as
described in ‘Supported
Commands’ section.
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Reference Pressure value **
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Reserved data
0x49
8 bytes - TBD
0x53
Raw absolute pressure value in Pascal (4 bytes)
** When the Units are changed, the Reference pressure value is
reset to zero, if an invalid character is sent, the units are changed
to the default unit (PSI).
Supported Commands
Command
‘d’ or ‘D’
‘p’ or ‘P’
‘b’ or ‘B’
‘k’ or ‘K’
Function
Change Reference pressure to current absolute
pressure.
Change units to PSI
Change units to millibar
Change units to kPA (kilo-pascal)
Usage Tips and Technical Details
Sensor Resolution: The internal resolution of sensor is 2 Pascal.
Depending on units configured for your sensor, your resolution will be
different. (e.g. if your sensor unit is in PSI, the smallest value
available will be 1 PSI).
Raw Readings: Highest resolution is available through raw readings
(in Pascal).
Reading Speed: From NXT, you can read up to 15 readings per
second.
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