OEM Differential Barometer/Altimeter (DBO433, DBO868, DBO915) User Manual v 1.6 December 2021 © Advanced Sensor Research Ltd. https://www.asr-web.
Features • • • • • • • Integrated MCU Corrected atmospheric pressure readings Derived elevations with customizable datum Temperature readings Mesh networking Simple serial interface Metric or Imperial output units Application Examples • • • • Indoor elevations Building pressurization monitoring Multi-node telemetry networks Altitude reference for UAVs Overview The DBOxxx series differential barometer/altimeter (patent pending) OEM module provides atmospheric pressures and derived elevations at a rover u
C) Multi-node telemetry. In this application the rover receives remote uncorrected pressure and temperature from multiple bases using a mesh network topology. The pressure data is absolute and not differentially corrected. Specifications Differential Pressure Accuracy: +/- 0.
1 144 287 430 573 716 859 1002 1145 1288 1431 1574 1717 1860 2003 2146 2289 2432 2575 2718 2861 3004 3147 3290 3433 3576 3719 3862 4005 4148 4291 4434 4577 4720 4863 5006 -1 -0.5 -1 -1.5 -2 -2.5 1 148 295 442 589 736 883 1030 1177 1324 1471 1618 1765 1912 2059 2206 2353 2500 2647 2794 2941 3088 3235 3382 3529 3676 3823 3970 4117 4264 4411 4558 4705 4852 4999 Typical Characteristics Modules were stationary for testing at a set fixed datum elevation of 0m.
Commands The general command syntax is command,{x{,y}} followed by an exclamation mark (!). Command 1,x! 2,x! 3,x! 4,x,y! 5! 6! 7! 8, x! 9, x! Description Set NetID, both base and rover must match. Valid range is x=1 to 999. Set NodeID, every NodeID on NetID must be unique. Valid range is x=1 to 999. Set Units. Metric x=0 (mb,m, C), Imperial x=1 (inHg,ft, F)). Average Elevation Datum and Base NodeID (differential mode preset, rover only). Valid Elevation Datum range is x=-9999.99 to 9999.99.
Rover output (differential mode) format is as follows, output will be ,A, (preset) until set: NetID,NodeID,D,BaseNodeID,Units, Differential Pressure,Pressure Residual, Local Elevation Datum, Differential Elevation, Elevation Residual*Checksum Checksum is a hex value calculated by applying XOR on each character in the string up to but not including the asterix (*). Base NodeID must be an available node in the rover telemetry stream output for commands 4! and 5! to output differential results.
Demo Software The Differential Barometer Demo software is available for download on our website at https://www.asr-web.com/support and allows users to evaluate the capabilities of the system. Note that a user must be a local administrator on a system in order to install and run this program. After installation edit the settings.txt file in the program installation directory to set the parameters.
When connected to the base, pressure and elevation graphs are absolute readings. The range corresponding to 0 on the graphs is shown in brackets in each title. The buttons on the bottom top row will be labeled NetID (x) where x is the current NetID and NodeID (y) where y is the current NodeID . To set a new NetID or NodeID enter it into the corresponding text box and click the button. In this mode the Ping button is disabled. The current Units can be changed on the bottom.
When connected to the rover, pressure and elevation graphs are absolute readings until a datum is set. The range corresponding to 0 on the graphs is shown in brackets in each title. The buttons on the bottom top row will be labeled NetID (x) where x is the current NetID and NodeID (y) where y is the current NodeID. To set a new NetID or NodeID enter it into the corresponding text box and click the button. In this mode the Ping button is enabled.
Absolute readings for available base telemetry can be viewed by choosing the Base NodeID using the NodeID combo box. To set the Elevation Datum enter it into the text box and click the Datum button. After the Datum button is clicked it will change to Adjust (x) where x is the current Elevation Residual as an average deviation from the preset datum, do not move the units during the calibration.
A log.txt file in the application directory stores the output with a date/time stamp.
Firmware Updates Firmware updates are available for download on our website at https://www.asrweb.com/support. The following is the firmware update procedure: 1. 2. 3. 4. 5. 6. Connect the OEM module to a USB-serial converter, the DSR/DTR line must be used. Connect USB-serial converter to a port on your local machine. Unzip the package. Launch a command window. Change the directory to the location of the package. Invoke update.bat with a single parameter which specifies the serial port number to use.
