Quick Start Guide

In order to start using eFlightWatt, you have to take the following steps:

  1. Copy eFlightWorks.exe from the CD to a hard drive or download the latest version from:
    No installation is required, simply start the software.

  2. Connect the ESC signal cable via the supplied Y-cable to the wattmeter, so that the two-wire section of the cable plugs into the wattmeter and 3-wire section with male plug is left unplugged (do not connect the battery yet!):
  3. off-line

    Connect all sensors, paying attention to polarity of RPM sensor and ESC connectors.

  4. Plug a USB cable from your computer into the mini-USB connector on the wattmeter.

  5. Start eFlightWorks software.  A wattmeter window should open:

  6. Click anywhere in Active sensors box and specify which sensors are connected to the wattmeter.  If RPM sensor is connected, set the number of poles (for a magnetic or a phase sensor) or the number of blades (for an optical sensor).  DO NOT select Throttle channel sensor, unless you are configuring the data logger for in-flight throttle recording!  In on-line mode, throttle level is always recorded, but activating this sensor will disable the ESC control.

  7. Set monitoring conditions for on-line mode via Options/Wattmeter options menu:

  8. To configure the data logger for off-line recording, you have to set start/stop conditions. Click anywhere in Start/stop conditions for off-line recording box of the wattmeter window and specify either Ion or Ton for start and both Ioff and Toff for finish conditions. The text on the right will explain the meaning of these parameters. On the first page of Set recording parameters dialog, you may also select the measurement frequency, from 0.1 up to 63 seconds, which affects both on-line and off-line recording.

  9. Finally, connect the battery to the matching power connector of the wattmeter. You are now ready for on-line measurements: move the throttle slider with the mouse--the motor will start running and indicators in the wattmeter window will come to life! To start on-line recording, click at the golden CD icon or go to Tools/Start recording menu. To stop recording, click at the red stop sign or go to Tools/Stop recording menu.

  10. To record in-flight data, connect everything in a similar fashion (again, do not connect the battery, until you are ready to take off):


    If you intend to record the throttle channel in-flight (and you have activated Throttle channel sensor, when the wattmeter was connected to the computer), you have to use the supplied Y-cable to deliver the throttle signal to both eFlightWatt and the ESC. Again, similarly to the on-line recording setup, the two-wire section of the Y-cable goes to the wattmeter. If you are not recording the throttle channel level, you may plug the ESC directly into the receiver.

  11. To download the off-line recording from the onboard memory to the computer, simply connect eFlightWatt to the USB cable (you don’t have to connect the ESC and the battery) and select Tools/Read flash memory menu or click at memory contents indacator in Wattmeter window.

eFlightWatt Manual


  1. Connecting Sensors
  2. Operating Modes
  3. LED Blinking Codes
  4. eFlightWorks Software
  5. Developing Custom ESC Programs

Connecting Sensors

The ESC and the RPM sensor are plugged into the universal connector as shown in the picture below: the dark (black or brown) ground wire are closer to the center of the circuit board, while the light (white or yellow) signal wire is closer to the edge. Temperature sensors can be plugged either way.

Universal connector

The three-wire cable of any of the RPM sensors, an optical, a magnetic, or a phase sensor, plugs onto the same 3 pins of the universal connector. If you are using a phase sensor, its lone red wire should be connected to one of the motor wires as shown in the following picture (the ESC signal cable is not shown):

Phase sensor

If you use bullet connectors between the ESC and the motor, you may want to assemble a tap-in connector, by soldering male and female connectors (of the same type as used for ESC-motor connection--not all bullet connectors, even of the same size, are interchangeable!) together and attaching the red wire of the phase sensor in the middle:

Phase sensor

If your ESC has an integrated BEC, i.e. if it can power the receiver/servos, the central red wire should be present as, by sensing the BEC voltage, the wattmeter detects the battery connection (the exact detection of the moment, when the ESC gets powered, is important for programming ESC with time driven parameter selection, e.g. Hyperion Titan of Hacker X-series, among many others). If your ESC lacks BEC, which is the case with all OPTO controllers, you have to power the ESC with the help of a small RX battery or an external BEC unit (often called "UBEC" or, in CastleCreation rendition, "CCBEC").

If the battery is connected to the wattmeter first, before the load, an ESC and a motor, gets connected, the wattmeter performs internal calibration: it measures the current consumed by its own circuit and saves it in its flash memory; later this value (about 20...40 mA) is subtracted from the measured current to eliminate the effect of the wattmeter presence. The current caused by the wattmeter itself is fairly constant, but in order to maximize the measurement accuracy, you may want to repeat this internal calibration every time the measurement conditions or battery voltage substantially change, e.g. you switch from 3S to 6S battery or move from air conditioned room to hot flying field. If nothing changes much, you may keep the ESC/motor connected to the wattmeter all the time and only disconnect the battery


Operating Modes

eFlightWorks can work in either "on-line" mode, while connected to a computer, or in autonomous "off-line" mode:

Besides the two "working" modes, the wattmeter can be switched to firmware update mode; after the update, it returns to the on-line mode.

LED Blinking Codes

There are two Light Emitting Diodes (LED) on the top side of wattmeter, one is green, the other is red.
These LEDs indicate the following conditions:

Red LED Green LED Wattmeter state
First, couple of quick blinks; then stays OFF First OFF; then slowly blinking: 1 sec ON, 1 sec OFF In on-line mode, having successfully initialized after beeing connected to USB.
Stays OFF First OFF; then blinking 3 times a second In off-line mode, having successfully initialized after beeing powered by a battery;
ready to start off-line recording as soon as the start conditions are met.
Blinking Solid ON Recording data in off-line mode.
The number of quick red LED blinks followed by a short pause indicates the amount of flash memory already recorded:
  • 1 blink = 0...19% of flash memory recorded
  • 2 blinks = 20...39% recorded
  • 3 blinks = 40...59% recorded
  • 4 blinks = 60...79% recorded
  • 5 blinks without pause (constant fast blinking) = 80...99% recorded
  • Quickly blinking together On-board flash memory is full (while the number of flight may not yet be exceeded).
    Quickly blinking in turns The number of flight may has exceeded the maximum (while on-board flash memory may not yet be full).
    Both LEDs blinking very fast In bootloader mode, ready to start or have started firmware update.
    Stays OFF Solid ON Initializing--should only last for a couple of seconds or less (though, sometimes, may last up to half a minute). If initialization succeeds, the green LED will starts blinking.
    Solid ON Stays OFF Invalid state (should never happen).

    eFlightWorks Software

    eFlightWorks is a modern application with Multi Document Interface, conventional menus, keyboard shortcuts, and flexible toolbars with command icons. It is ported onto different computer platforms and is translated into different languages.

    The Windows version of eFlightWorks software consists of a single self-sufficient executable file, eFlightWorks.exe. This application does not require any additional DLLs, does not need .NET or any other optional Windows components. The "installation" is virtually non-existent: you simply copy eFlightWorks.exe from the CD-ROM or download it from MileHighWings server and place it in any folder on your hard drive (it can even be launched directly from a CD-ROM). eFlightWorks saves the data, which needs to be persistent between the sessions, in Windows registry under

    If eFlightWorks software is launched without any MileHighWings defice connected, an empty application window will open and About window will only liste information about the software:

    no device

    Once any of MileHighWings devices, e.g. eFlightWatt wattmeter, is connected, the menus/toolbars are extended and About window lists the device description:

    About with device

    The main Wattmeter window, which is always present when eFlightWatt is connected and closes automatically, as soon as you diconnect the wattmeter, displays the active recording settings, measured voltage and current, as well as the state of the onboard memory:

    About with device


    The following menus are implemented:

    File Menu

    File menu holds the standard open/save and exit commands:

    Menu File

    Open command displays Open eFlightWorks data file dialog, which allows you to load any of eFlightWorks native files:

    Loading a measurement recording file displays the graph (the visibility of the data table on the left is controlled by Options/Display options menu):

    Opening an interface settings file brings up an interface settings window:

    A channel recording file displays the channel data recorded with MileHighWings USB v.4 interface:

    Save command, as expected, saves the selected flight under its current name. If the flight was just recorded live or downloaded from the flash memory, it has a default auto-generated name like


    In order to change the file name to something more descriptive, please use Save command, which also allows you to export the flight data into a Comma Separated Values (.csv) or Tab Separated Values (.tsv) file, which can then be processed by conventional spreadsheet applications like Microsoft Excel:

    Saving several recordings in separate .tsv files and then loading them into a single Excel spreadsheet is a convenient way to compare several flights or tests.

    View Menu

    View menu controls visibility of toolbars and the throttle slider:


    Window Menu

    Window menu contains standard window control commands, which arrange the windows and let you switch between them:

    A group of commands in the middle of Window menu, Mouse zoom, Mouse pan, Mouse select, and Mouse scan, determines the effect of the mouse click and the mouse drag (moving the mouse while holding the left button down) over the graph area of a flight data window. When you drag the mouse in zoom mode, it draws a rectangle, which will become the boundary of the graph for the new zoom-in level:

    If the current view is zoomed in, switching to Mouse pan mode permits panning the graph with the mouse (you can also pan the graph with mouse wheel and arrow keys in any mode).

    While in Mouse select mode, dragging mouse also draws a shaded rectangle while selecting all the data points, which fall within the rectangle. If the data table is also visible, the table cells are selected at the same time as the rectangle covers data points in the graph:

    Dragging the mouse in Mouse scan mode, draws a vertical line across the graph area, which moves together with the mouse. As this line intersects the data curves, the nearest data points get selected in the graph and in the table, then the values for each curbe are interpolated between these two measurement points and displayed near the mouse pointer:

    If you keep a Shift key pressed down, while dragging the mouse, an area on the graph is selected and integral/average data for the selected section is displayed in addition to the current point values:

    Options Menu

    Recording parameters sub-menu gives access to Set recording parameters dialog as well as displays the current values of the sampling rate and off-line recording start/stop criteria:

    Display options command controls the way the measurement data is displayed--you can choose to show the data in the form of a table or as a graph, or both table and graph side-by-side (only those curves, for which the data was measured or calculated, are listed):

    Clicking at one of the color boxes in Curves column of Data plot box opens the color selection dialog:


    General page of Wattmeter recording settings dialog allows you to choose the measurement rate of 0.1, 0.2, 0.5, 0.8 second or from 1 to 63 seconds with 1-second step as well as to enable an additional external shunt:

    Sensors/Propeller page permits choosing active sensors. If RPM sensor is selected, Tachometer parameters and Propeller panes are enabled, where you can select the RPM integration period, number of poles, gearbox ratio, propeller parameters as well as your elevation above the sea level:

    Please note that the gearbox ratio should be specified only when the RPM sensor is measuring the motor RPM directly, i.e. it's either magnetic or phase sensor. If you are using an optical RPM sensor, which measures the actual propeller RPM, you should dsable the gerabox (even if your motor has one!).

    Clicking at the big button with the picture of a propeller under propeller Type and Size brings up the propeller parameter window:

    A number of popular propellers is listed as "standard" but you can also supply your own thrust and power constants to be used in the commonly accepted equations: C*(RPM/1000)N. Please note that these constants should correspond to the seal level conditions, while your altitude above the sea level will be taken into account based on the entered Elevation above sea level value. Also note that Cthrust constant has to be given in grams; conversion to the Imperial unit system, if selected, is done after the thrust value is calculated.

    User supplied propeller constants can be loaded from a propeller parameter file. Please refer to the comments in a sample file for the information how to prepare a propeller parameter file.

    Please note that changing the number of blades has no effect on the propeller constants. If you want to analyze a propeller with a different number of blades, you must manually adjust its thrust and power constants.

    Off-line recording start/stop page of Set recording parameters dialog allows you to specify start and stop criteria for off-line recording. The recording start can be determined by either the threshold current, Ion, or by the time delay after the battery is connected, Ton. The stopping criterion includes both current, Ioff, and time, Toff. When these values are changed, the resulting criterion is explained in simple words at the right:

    You should select the start/stop values wisely: if you select them improperly, a single flight may be split into many sections, the maximum number of off-line flight records, 50, will be exceeded, and the recording will stop. If you want to make absolutely sure that the off-line recording lasts until you disconnect the battery, set Ioff equal zero.

    Please be aware that changing recording parameters invalidates previous off-line flight records stored in the on-board flash memory--before the changes come into the effect, you must either erase or save all the off-line measurement data:

    Wattmeter options dialog controls only eFlightWorks software operations--changing any of this parameters does not affect eFlightWatt wattmeter configuratiuon and does not invalidate off-line recordings in the onboard memory. First page of this dialog allowes you to set monitoring conditions for on-line measuremet:

    As soon as any of these conditions is met, all on-line recording operations (i.e., simple recording, battery testing, or throttle playback) are stopped and the trottle level is reduced to the predefined level. If overload monitoring is active, the corresponding indicator in Wattmeter window, voltage or current, displays a dark red area in the overload zone; if the monitoring condition is disabled, the overload zone is filled with light red color.

    Please note that overload monitoring is not performed if Draw graph after the data is gathered and recordig stopped option is selected on Live Recording page (this is done in order to enable on-line recording with wery slow computers):

    Graph Title page allowes you to construct a title and a subtitle for the newly created recordings using teplates:

    Each template may contain regular text, which will be transferred to the final title/subtitle without changes, as well as eFlightWorks variables, which will be substituted with their vaues during the title/subtitle generation.
    The title template may include the following variables:

    ($date) - the current date in the format determined by the configuration of your computer, e.g. 10/25/2007 in the US or 25/10/2007 in Europe

    ($time) - the time at the beginning of on-line recording or download of off-line data in the format determined by the configuration of your computer, e.g. 8:45PM in the US or 20:45 in Europe

    ($prop) - the name of the propeller, selected on Sensors/Propeller page of Wattmeter recording settings dialog.

    In addition top these variables, the subtitle template can also include:

    ($duration) - the duration of the recording

    ($charge) - the charge

    ($maxV), ($minV), and ($avgV)- maximum, minimum, and average voltage values

    ($maxI), ($minI), and ($avgI)- maximum, minimum, and average values of the current

    The most important difference between the title and subtitle is that the title is generated at the moment, when the recording is created, and doesn't change afterwards. The subtitle, from the other hand, is updated during the on-line recording and is finalized when the recording is finished.

    Finally, the Files page of Wattmeter options dialog configures the prompting behavior:


    Tools Menu

    Start recording and Battery test commands are enabled only when the battery is connected to the wattmeter, while Read flash memory and Erase flash memory are awaylable only if the onboard memory is not empty:

    Once you start on-line recording, the gold CD icon changes to a red STOP sign, clicking which stops the recording.

    Read flash memory command allows you to download the off-line flight records and optionally erase them from the flash memory:

    The flights can only be erased "from the tail" of the flight record list. So, if you have, say, 5 flights recorded and you downloaded flight 3, you can erase flights 3, 4, and 5, but you can't erase just flight 3 while keeping flights 4 and 5.

    Start throttle sequence playback command (it changes to Stop..., while the playback is in progress) opens Throttle playback window:

    Throttle program can be specified in an .eft file (please refer to the comments in a sample throttle script file) or copied from a previous recording, which contains the throttle data. The last source, *.ecr file, is a trasmitter channel recording created by MileHighWings USB v.4 interface. Please note that a throttle script file provides more accurate data as it allowes one to specify throttle level discontinuities as well as linear throttle variation over time.

    Voltage cutoff value is shared with the Overload Monitoring cut-off voltage .

    IMPORTANT: If your computer is too slow, slower than Pentium II 600MHz, please increase Sampling rate to 0.2 or even 0.5 seconds. If the live measurement data is received faster than your computer can process it, some throttle changes may be delayed and some throttle steps may take longer than requested.

    Program ESC command opens a window with a list of "standard" controllers:

    Once you select an ESC and click Program this ESC button, a corresponding program window opens:

    Please note that some of the controllers, like Hyperion Titan above, only allow for a single setting change per ESC programming session. For such ESC, you will have to repeat programming several times, if you need to change several settings.

    Other controllers, like hexTronik S60 below, support changing several settings, so several programming groups can be selected and will be executed in one run:

    If an ESC has an integrated Battery Elimination Circuit (BEC), eFlightWorks detects the moment when the battery is connected and starts programming automatically:

    For an ESC without an integrated BEC, you have to manually initiate the programming sequence by clicking Ok button as soon as you connect the battery:

    Battery test command opens Battery test window, where you enter the discharge current and cut-off voltage:

    You have to make sure that the test current you specify is, first, safe for battery, ESC, and motor (i.e. the current value is within the continuous running specs of each of these components) and, second, that this current can be reached when the throttle increases to 100%. If your power system only draws, say, 18A at full throttle, the specified 20A test current will never be achieved.

    Help Menu

    The Help menu shows About window current eFlightWatt settings:

    Current eFlightWatt settings command opens eFlightWatt Settings window, which lists both the hard-wired parameters of the wattmeter as well as adjustable measurement settings:

    Developing Custom ESC Programs

    eFlightWorks allows to customize ESC program for your particular controller as well as save program pre-sets for quickly configuring your ESC for a particular application.For both, creating programs for a new ESC or making programming pre-sets for one of the existing controllers, it's easier to start by copying of a program for a similar ESC. To do that, go to eFlightWorks menu Tools/Program ESC (shortcut key Ctrl+E), select an ESC from the list, and hit 'Edit copy of this ESC' button. After editing the program, it has to be saved as a custom ESC definition, which can later be loaded by hitting 'Load custom ESC' button in Program ESC dialog.

    At the moment, eFlightWorks supports four programming types (for detailed description of each programming type, please refer to the programming documentation for the referenced ESC):

    1. Single choice per group, answering Yes switches to the next group (unique to Castle Creations Phoenix line)
    2. Two-choice and throttle-proportional groups (Cool Running CoolESC or Castle Creations Thunderbird line)
    3. Single choice in timed sequence (like Hacker X, Hyperion Titan, etc.)
    4. Two menu levels with single choice in timed sequence on each level (like most hexTronic, Tower Pro Gen.II and their clones)
    Currently, the last ESC type can be programmed, but the program can't be edited. The ability to edit two-level ESC programs will be added in one of the upcoming software releases.

    All the ESC programming editing is done via Edit ESC programming dialog, which always has 'Starting programming' and 'Finishing programming' pages and a number of programming groups or categories between them:

    The name of the ESC should be unique, there can't be two controllers with the same name in the list.

    Programming type selection is is disabled as long as there are programming groups between Starting programming and Finishing programming pages as all the programming grpups have to be of the same type and there's no conversion between different programming types.

    Auto detect battery connection checkbox specifies if eFlightWorks should monitor the voltage at the red wire of the ESC connector and start programming as soon as the voltage is detected. Otherwise, the programming starts after the user hits Ok in the Starting ESC programming window.

    To get into the programming mode, various ESCs require certain throttle level when the power is connected--refer to your ESC description and set this value in Throttle level when battery is connected spin box. In addition to that, some controllers (like the ones from Castle Creations) require several throttle steps to get into the programming mode--set the number of steps, the throttle levels and durations in the corresponding fields on Starting programming page.

    Clicking Add group before and Add group after buttons adds a programming group, corresponding to the selected programming type.
    Programming groups of "Two-choice and throttle-proportional" type, like CoolESC controllers by Cool Running or Thunderbird line by Castle Creations, are the easiest to program as they are not time driven, i.e. a person can take as much time as necessary before specifying the choice. Programming group page for ESCs of this type looks like this:

    You can select the name of the group from a list of existing group names or enter your own name. The advantage of selecting one of the existing names is that this name will automatically be translated into other languages when eFlightWorks is switched to a different language, while the custom name will always remain the same.

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