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User Guide for RC Speedo for the Android Smartphone

Basic use and configuration of RC Speedo for Android is meant to be very easy. For 90% of the users, you can simply start up the app, click "Start Listening" and begin flying your RC plane for the app to begin announcing the speeds of your passes. To configure the app, press the "menu" button and click the "Settings" button. Following are an explanation of the various settings:

  • Enable Sounds - Turns speed announcement on or off. If this is disabled, the phone will no longer speak the speeds to you.
  • Change Doppler Mode - Configures the app to better detect the speeds of "special" aircraft. If you are having trouble getting RC Speedo to detect the speeds of your plane, you may want to try some of these other modes.
    • Default Mode - The standard mode that should detect most speeds. It also has the lowest probability of reporting "bad speeds", which sometimes will occur when you blip the throttle or more than one plane are in the air.
    • 100MPH+ Mode - This mode better detects high speed planes, but will not detect passes under 100MPH at all.
    • Fast Pass Mode - This mode is for making passes with limited airspace, where you will not have the full ~2 seconds of full throttle required on approach. This mode will pick up significantly more "bad speeds".
  • Change Units of Speed - Allows you to switch between miles per hour (MPH) and kilometers per hour (KPH).
  • Enable GPS - Tells the app to use your phone's GPS device to determine the temperature using your current location. You'll want to turn this off and manually input temperatures if you are trying to doppler a video.
  • Temperature - Allows you to manually set the temperature in Celsius for the app. C = (F - 32) * (5 / 9) . Setting this manually will turn off the GPS option.

How to make speed passes that RC Speedo can pick up and correctly report

  • Try to minimize background noise such as talking, wind, and music while making a pass.
  • Hold the throttle at the same position for approximately 2 seconds before the pass and 1 second after the pass.
  • If at all possible, keep the smartphone out and in the open (ie not in a pocket or in a bag)
  • Try to level out the passes as you fly by yourself and the phone (ie don't make a huge U)
  • Go as low as you are comfortable doing on each pass. Lower=higher sound, which is easier for the phone to pick up.
  • Make your passes as close to yourself as you are comfortable doing. The further out the pass is, the more inaccurate the speed reading will be.
  • Use RC planes that have high-RPM props, such as pylon racers, pushers, or EDFs.
  • Try and fly solo when you are doing speed tests. It can be very difficult to differentiate between your aircraft's sound and another's.
  • Make sure the temperature is right for whatever you are trying to doppler. 10 degrees C can make a big difference in speed readings.

Things you can do with RC Speedo
Besides what it was meant to do, you can use the RC Speedo app for other cool things! Things I have tried include:

  • Doppler videos for people online by putting your phone next to your computer speaker and playing a video of some passes.
  • Put a high frequency sound emitter (like a loud piezzo buzzer) on something that moves and making passes with that! Remember: RC Speedo is incapable of detecting speeds below 25MPH.

The RC Speedo android app acts as a real time announcer for the speeds of passing radio controlled aircraft. It uses a signal processing algorithm on sound that is being recorded to perform doppler analysis on what the phone is hearing in real time. This method of finding speeds is extremely CPU-intensive. While RC Speedo has been tested on the oldest android phone (the G1), it did work significantly slower and missed more speeds on average than it did on more modern phones, such as the Motorola Droid or the HTC Evo. Please keep this in mind if you are running the app on one of these slower phones.

Logging is a new feature in RCSpeedo released on 1/18/2011. You can use the logging features to keep track of how the top speed of your airplane changes over time. You can assign each airplane its own log, or multiple logs for each airplane (for different flight packs, etc), and export the log at any time to a spreadsheet file. To access the logging menu, press the menu button in RCSpeedo and select the "Logging" option.

How to create a new log: In the logging menu, enter the desired name for your new log in the "New Log Name" field. This name should identify the airplane for which it's for as well as any other details you think are pertinent. Next, click on "Create New Log". The new log will be created in the /rcspeedo/ directory on your SD card and will show up in the current logs drop down.
How to delete a log: Select a log that you no longer wish to have on your phone and click "Delete Current Log". The app will ask you to confirm your intent to delete the log and then it will be removed.
How to save results from some speed passes to a log: After you are done with your speed runs, hit the "Stop Listening" button and verify that some speeds have been detected and recorded on the main RCSpeedo screen. Next, go to the logging window throw the menu button. At the top of the window, use the "Change Current Log" drop down to select the log you wish to save the new data to. In the center of the window, there is a "Description" field; fill this out with any relevant information about the speed runs you have just accomplished (ie date, time, latest mods, wind speed, etc), now just hit "Save Changes to Selected Log". The passes on the main screen will be cleared out and sent to the log you selected. You may now return to the home screen.
How to view a log by connecting your phone to a computer via USB: Note: you must have a spreadsheet program such as Excel to view these logs. If you need a free spreadsheet program, I highly recommend finding and installing an office suite called OpenOffice. To get to the log files, attach your phone to your computer using a USB cable and mount it as a USB drive. Now, browse to the "rcspeedo" directory on your phone and you will see all the logs. You can freely drag and drop these logs to your computer. Note that if you delete the logs here, they will disappear from RCSpeedo as well. Furthermore, I highly recommend you do NOT edit these logs on the phone, if you want to make changes, do it on a copy you save to your computer's hard drive.
How to email a log: In the logging menu, select a log you want to email by pulling down the "Change Current Log" drop down. Once you've selected a log, click "Email Selected Log", and your default email client will be brought up with the log automatically attached.
How to open the logs (Windows): RCSpeedo outputs its log in the "CSV" file format. This is a rudimentary spreadsheet format that may require some settings changes. If your spreadsheet program asks you how you want to "parse" the log, make sure you set it as "Comma delineated" only. Other options may include spaces, semicolons, and tabs, but none of these should be selected.

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