Introduction ................................................................................................................................ 3 How it works .............................................................................................................................. 3 Key features................................................................................................................................ 3 System requirements .................................................................................................................. 4 Hardware .................................................................................................................................... 4 Specifications ......................................................................................................................... 4 Using the RC Altimeter #2 PRO module ................................................................................... 5 Powering the module.............................................................................................................. 5 Mounting the module ............................................................................................................. 5 Operation ................................................................................................................................ 6 PC USB Interface ....................................................................................................................... 6 PC Software................................................................................................................................ 6 Installation .............................................................................................................................. 6 Startup .................................................................................................................................... 7 Connecting to the hardware.................................................................................................... 7 How to config the RC Altimeter #2 PRO module ................................................................. 8 Working with the data .......................................................................................................... 10 Firmware upgrade .................................................................................................................... 11
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RC Altimeter #2 PRO was designed to provide a lightweight, compact device for measuring and recording altitude over time. It was designed specifically for use onboard a radio controlled (R/C) aircraft, but should be useful in other applications. RC Altimeter #2 PRO transmits current altitude, maximum altitude achieved in flight, vario and battery voltage, via RF link to ground unit RC T1000. If RC GPS module is connected to module it will also transmit ground speed and distance from R/C pilot.
The RC Altimeter #2 PRO module uses a high-resolution barometric pressure sensor system to detect small changes in air pressure that occur due to changes in altitude. It is sensitive enough to detect altitude changes of less than one meter. Because it is so sensitive, it is also sensitive to changes in weather and local pressure variations. The designed use of this device is for measuring short-term altitude changes in R/C aircraft. Long-term altitude readings will vary considerable due the varying atmospheric conditions. It is best used to measure relative changes in altitude. Module uses a 433MHz two way link to transfer data from yours R/C plane to RC T1000 ground module. Data transfer is digital so there won’t be any noise or wrong data reception.
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Lightweight at only 9 grams with telemetry and JR cable Small · 37 mm x 19 mm x 7 mm With RC T1000 module it will work as variometer with audio tone Records altitude data for later review FXJ switch function integrated PC USB interface for configuration, firmware updates and data download / review Export data in *.txt format or as JPG image Accepts wide range of input power: 4 – 20 volts DC. Power it from your aircraft receiver Every unit is tested in pressure chamber up to 950m for its accuracy Transmits current altitude, maximum altitude achieved in flight, vario (climb rate) and battery voltage in real time With RC GPS module it will transmit additional information as ground speed and distance from R/C pilot Supports RC GPS module and record all GPS data in order to see your flight in 3D with Google Earth and airspeed graph will be shown on PC software
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PC with one of the following operating systems: Win98, Windows ME, Windows NT, Windows 2000, Windows XP, Windows Vista. Available USB port. 2 megabytes Hard Drive space.
Figure 1 shows the RC Altimeter #2 PRO hardware module. The module includes 433MHz transceiver for transmitting data to ground with 17cm long antenna. The JR cable is used to connect to a radio-controlled aircraft’s onboard receiver, which powers the RC Altimeter #2 PRO module. The 3-pin connector serves as servo pass-through or as output for FXJ switch function. A modular connector is used to interface to a PC for configuration and to download altitude data. Servo Pass-through connector (behind) Antenna To receiver
Connector for PC interface
433MHz transceiver
Figure 1. The RC Altimeter #2 PRO Hardware
Board Dimensions Weight Temperature Range1 Input Voltage Range Input Current Measured voltage Maximum altitude1 Minimum altitude1 Memory capacity Displayed altitude resolution Output power Range
1.46” x 0.75” x 0.28” 37 mm x 19 mm x 7 mm 9 grams -10°C…+60°C 4.0 – 20.0 volts DC 36 milliamps 4.0 – 18.7 volts DC Recorded: 3100.0 meters/feets/yards Recorded: -3100.0 meters/feets/yards 16000 samples. 1 meter (1 foot). Up to 10mW (10dBm) at 433MHz More than 1 km (depends on antenna installation)
1
Specifications are taken from component ratings and system limits and may not have been tested to the full extent of the specified ranges.
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To power the RC Altimeter #2 PRO module, plug the 3-pin connector on JR cable into a spare receiver channel on the R/C aircraft. If you do not have an open receiver channel, you can plug the RC Altimeter #2 PRO into the receiver, and the plug that channel’s servo into the RC Altimeter #2 PRO servo pass-through connector. Be sure to observe proper polarity when plugging the connector into the receiver. For non-R/C use attach a battery to the servo passthrough connector. A JST style connector can plug directly into the 3-pin pass-through connector. Again, be sure to observe proper polarity, or damage may result. The 3-pin passthrough connector is oriented with the same polarity as the adjacent servo wires.
The RC Altimeter #2 PRO module can be mounted in one of two ways: •
Inside the fuselage of the aircraft. There should be an opening of at least 0.5 sq. cm to allow air pressure inside the fuselage to equalize with the atmospheric pressure. For many aircraft, the fuselage is not airtight and is sufficiently vented to the outside air.
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On the outside of the aircraft. The pressure sensor should be at a right angle to the airflow for maximum accuracy. This means the air stream is flowing across the hole in the pressure sensor, not directly into or away from it. If possible, mount it away from the prop wash, because the measured altitude can increase by over 60 meters due to airflow from the prop.
The module can be mounted using double stick tape, cable ties, or Velcro. Velcro is recommended so that the module can be removed and interfaced with the PC for downloading altitude data. Be sure that the module is not touching any metal surfaces. Shorting the metal contacts on the module could short the power system, resulting in a radio system failure. Don’t mount module on top of power batteries when using e-motor planes because they get hot and this can affect on altitude readings up to 30m. Also be sure to keep the module away from water, fuel, or other liquids. Always range check the aircraft’s radio system before flying with the RC Altimeter #2 PRO module installed to verify that there is no system interference. For maximum range a full length of antenna should hang free from fuselage.
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The first thing when you turn on the module will set zero altitude and create new flight. When the module is setting zero altitude you must make sure that the module will be in standstill. In order to view data you must use RC T1000 module. Via RC T1000 module you are able to change any logger settings, set zero, erase data and download data from RC Altimeter #2 PRO to RC T1000 via 433MHz link on the field without computer.
" The PC USB interface connects to the RC Altimeter #2 PRO module’s 4-pin connector. RC Altimeter #2 PRO gets power from USB interface so no external battery is required. USB drivers you can download from www.rc-electronics.org web site under Downloads -> Software. After installation virtual COM port will be created. Please be sure that this virtual COM port is number is under 10.
Figure 2. USB interface
No installation is required for the RC Altimeter PC software. You can download PC software from www.rc-electronics.org internet site. After download, run RC_Altimeter_Logger.exe file. RC Altimeter #2 PRO will work with PC software which version is above 1.3.0.
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When you run RC_Altimeter_Logger, the following screen will appear:
Figure 3. RC_Altimeter_Logger startup screen
After you run PC software it will start searching for the RC Altimeter #2 PRO module on all free COM ports up to COM 10. When PC software has found the module or when you press on “Device” button the “Device” window will appear.
Figure 4. RC_Altimeter_Logger Device window
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If the connection was successful status line will indicate “Connected to COMx”. Once connected, module information and configurations will be read from the module and then you can download data by clicking on “Download Data” button, erase data by clicking on “Erase Data” button, or configure the module with new settings. In “Name Flights” window you can give name to all saved flights and in “Pilot” window enter name of a pilot. You must do that before you click “Download Data” button.
Units
This sets the units for the module’s recorded altitude. Interval
You can select one of three options: High, Medium or Low. If you chose High, data will be stored three times in second, if you chose Medium, data will be stored every second and if you chose Low, data will be stored once in every ten second. Trigger
You can select one of four options: Trigger OFF, Always ON, Altitude Trigger or RC Trigger. • Trigger OFF: Logging function is turned off and no data will be stored. This option is good when you need only maximum altitude, because the module will be able to do the most altitude sampling or when use RC Altimeter #2 BACIS with RC GPS module in order to store only GPS data. • Always ON: After power on, the module starts to save data until it is full. • Altitude Trigger: Recording will start after the altitude measured exceeds altitude that you entered in Altitude Trigger box. • RC Trigger: You must connect the module in spare receiver channel and then via this channel you can start recording altitude data from your RC transmitter. In Reverse RC Trigger Direction check box you can select if you want recording to start on full or minimum position of yours transmitters stick/switch. Read Configurations
Click the “Read Configuration” button to download the module’s current configuration to the PC program. Write Configurations
Click the “Write Configuration” button to upload the new configuration to the RC Altimeter module. The module will store the new configuration in non-volatile memory.
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Record External Trigger
If checked marker will be recorded with next altitude when on receiver channel that RC Altimeter #2 PRO is connected impulse length change from min to max or max to min is detected. This function is used for aerial photography to know from which height photo was taken or when towing your sailplane to know on which altitude did you un-hook. It is also useful for later review of flight data to mark altitude and you can see what was happening there (which height, did yours plane climb or sink, …). RF Channel Nr
Select on which channel yours RC Altimeter #2 PRO will transmit data. In order to work properly you must have set the same channel on RC T1000. FXJ Switch
If you want to use FXJ switch function you must check FXJ Switch Enabled and then you can enter FXJ Switch altitude. In order for proper use of this function when you power up RC Altimeter #2 PRO module the channel to which this module is connected must be in min position (example: throttle off) or in position that you want it to be when you exceed inserted altitude. The module will remember this position and after exciding FXJ switch altitude it will mimic the same state on this channel (example: when your e-sailplane wills excide inserted FXJ switch altitude motor will be shout off). It can mimic only full or minimum position! FXJ switch function has control over that channel for 10s and after that you have control on this channel again. FXJ function will automatically reset when your plane will be below 20m. This function is useful for towing your sail plane when you want to un-hook on the same altitude every time. Then you must connect servomotor for hook to RC Altimeter #2 PRO module. It is also useful for training F3J category with e-sailplane.
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Description of all flights
All flights graph
Marker
Vario graph for current flight
Selected flight graph
Description of selected flight
Figure 5. New Flights window
Selected flight is colored yellow in all flights graph and is displayed in selected flight graph. If you click right mouse button on graph you can move it. To zoom it click left mouse button on graph and select area from upper left to lower right. To restore graph click on it with left mouse button and pull from lower right to upper left. If you click on two points on graph you will get info of time difference, altitude difference and average vario between these two points. Recorded markers will be shown as green cross with marked altitude. “Flight description” window shows the pilot name, date of download, maximum altitude in current flight and its duration. You can add any text in this description and in description of all flights. Flights
Here are all flights that were stored in the RC Altimeter module. Name of those flights starts with word inserted in “Device” window -> “Name Flights”. Flight can be deleted (select the flight and press Delete button on PC keyboard or right click on flight -> “Delete”). If you create new flights it is possible to drag and drop flights from one window to another. Doubleclick or right click -> “Rename” on flight will rename it.
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Graphs
Here you can print altitude graph or export data. You have three options for exporting: • Export ASCII: Current flight will be exported to *.txt file • Export Image: Current flight with flight description will be exported to *.jpg file • Export GPS data: If RC GPS module was connected and GPS data was recorded it will be exported into *.kml file for Google Earth review. Settings
Here you can set/choose units for altitude graph or speed graph (if GPS data is recorded) and set vario interval. This setting will have effect on vario graph. You can enter on how long interval you would like vario to be calculated. View Select if you want to see vario or speed (if recorded) graph.
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The RC Altimeter #2 PRO module supports the ability to upload new firmware to the module. No installation is required for the Firmware Upgrade software. You can download it from www.rc-electronics.org internet site. After download run Firmware Upgrade.exe file. Select correct COM port and then specify the new firmware file (RC_Altimeter_v2.xx.hex). After you have selected firmware file click the “Upload” button. After pressing “Upload” button, quickly connect USB interface to RC Altimeter #2 PRO and upload of new firmware will start. You should only use a firmware update file specifically provided for the RC Altimeter #2 module. Using an incorrect update file will render the RC Altimeter #2 PRO module inoperable.
select COM port select firmware file Figure 6. Firmware uploader
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