Annex 2 – Using an external GPS
Although this is not essential to obtain exceptional accuracy of results, PerfectPower offers you the possibility of using an external GPS communicating via Bluetooth with it to further optimize its accuracy of results (from 1% to 0.5% for power measurements) in mode 1 (Accelerometer + GPS) and simplify the measurement procedure (performing power measurements on a rolling start, eliminating the accelerometer calibration phase while driving for braking measurements, and completely freeing the phone from any mounting requirement) by using mode 2 (GPS only). PerfectPower recommends two:
- A RaceBox Mini or Micro (25 Hz), driven by PerfectPower and allowing the use of mode 2 (chapter 1)
- The SkyPro XGPS 160 (10 Hz), requiring the use of a third-party Bluetooth GPS application (chapter 2)
Note 1: All info on the measurement mode in chapter I-0-B.
Note 2: PerfectPower also drives the RaceBox Mini S, but does not specifically recommend it since technically it is identical to the RaceBox Mini, the only difference is that it can record measurements that can then be used but PerfectPower does not use this function and always processes “live” the information received from the RaceBox.
1) Using a RaceBox Mini or Micro
The RaceBox Mini & Micro is a “Bluetooth Low-Energy” type device, able to send and receive information with any type of device supporting this type of communication, such as any modern smartphone.
The communication process between PerfectPower and the RaceBox Mini & Micro has been designed to be as simple and comfortable as possible so that you can concentrate on the quality of your measurements and not have to worry about the RaceBox Mini & Micro once this one is installed in the car, and is based on a cycle of 3 long-clicks on the chrono, located in the center of the main screen:
- The first starts a 15 s SCAN during which PerfectPower searches for all available “Bluetooth Low-Energy” devices nearby. If it finds your RaceBox Mini & Micro within the given time limit, it stops the SCAN and is then ready to connect. If it doesn’t find it, you can restart a new SCAN until it does.
- The second allows PerfectPower to CONNECT to the RaceBox Mini & Micro, which signals this connection by emitting a blue light.
- And the third allows PerfectPower to DISCONNECT, the blue light therefore stops being emitted
Regarding the installation of the RaceBox Mini & Micro in the car, I let you refer to the documentation provided by RaceBox.
Regarding its use, as said, everything has been thought out so that it is completely forgotten, and once it is connected to PerfectPower (blue light on), the measurements take place EXACTLY as usual! The only visible difference on the phone compared to classic measurements using the phone’s internal GPS at 1 Hz: the speed display is in red (instead of white), with an accuracy of 0.1 km/h (instead of 1 km/h), and… at the frequency of the RaceBox Mini & Micro i.e. 25 Hz (instead of 1 Hz) and therefore 25 displays per second!
Note 1: All SCAN & CONNECTION & DISCONNECTION actions are always reported by PerfectPower via pop-ups, whether successful or unsuccessful, so you always know exactly where you stand with your RaceBox Mini & Micro.
Note 2: Everything has been thought of to limit energy consumption as much as possible (Bluetooth being very energy-intensive as you can imagine), however the only action that remains YOURS to limit energy consumption is to remember to disconnect from your RaceBox Mini & Micro as soon as you no longer use it. Needless to say, however, that the connection is automatically cut as soon as you exit PerfectPower.
Note 3: It is of course necessary that Bluetooth is enabled on your phone when using the RaceBox Mini & Micro! However, here again, everything has been thought of to make things easier for you, and if your Bluetooth was disabled during the first long-click (the one for the SCAN), PerfectPower will allow you to enable it WITHOUT EVEN EXITING THE APP!
2) Using an external GPS via Bluetooth
To enable PerfectPower to communicate via Bluetooth with your external GPS, follow the 3-step process below:
- 1) Turn on your external GPS
- 2) Pair your external GPS with your phone (to do only one time)
- 3) Use the Bluetooth GNSS app (intermediary between your GPS and your phone)
Note: Not all external GPS devices are authorized by their manufacturer to communicate freely via Bluetooth with all applications on a phone! For example, the Dragy Box (an external GPS that is a direct competitor to the RaceBox Mini) can ONLY communicate with their Dragy proprietary software! The SkyPro XGPS 160 recommended by PerfectPower is obviously authorized, but it is not the only one, there are others.
1) Turn on your external GPS
Press the power button on your external GPS.
Note: This often requires a long press of 1 to 3 seconds, in order to prevent unwanted power-ups (and therefore battery drains).
2) Pair your external GPS with your phone (to do only one time)
The pairing process is the process that allows two devices to communicate via Bluetooth (in the present case, your external GPS and your Android phone). It only needs to be done once: once paired, the two devices are respectively “registered” for each other.
Note 1: Depending on your Android version, you may notice slight differences in menu names or locations.
Note 2: If your phone asks for a code during the pairing process, use “0000” or “1234”.
On your phone:
- Go to “Settings / Bluetooth”, and enable Bluetooth
- In this same menu, tap on “Available devices”
After a few seconds, the name (or identifier) of your external GPS will appear in the list of available devices: click on it, and in a few seconds your external GPS will appear in the list of paired devices: it’s done, your external GPS is now paired with your phone, that is to say it is recognized by your phone as a device with which it can communicate via Bluetooth.
On the other hand, it is not yet really connected to your phone: for this, you must use a third-party Bluetooth GPS application (called a “GPS Provider”) which will act as an intermediary between your external GPS and your phone, or more precisely between your external GPS and your phone’s OS: indeed, this application will retrieve the information from your external GPS AND immediately send it to your phone’s OS by replacing the information coming from your phone’s internal GPS.
So, PerfectPower, like all other applications on your smartphone that use GPS and that retrieve GPS information from your smartphone’s OS, will receive information from your external GPS!
There are several “GPS Providers”, the most recommended is the Bluetooth GNSS application available for free on Google Play at this link: Bluetooth GNSS. You must therefore download and install this application, then follow the instructions given in the 3rd point below to make it work correctly.
3) Use the Bluetooth GNSS app (intermediary between your GPS and your phone)
Three steps are required:
- Authorize your phone to use mock locations
- Properly configure Bluetooth GNSS
- Connect to the desired external GPS (yours, of course)
To perform the first step:
- Enable Developer mode on your phone (if it is not already enabled) by going to “Settings / About phone”, then tapping on Build number 7 times in a row: you should see a message confirming that you have just enabled Developer mode
- Go to “Settings / Additional settings / Developer options”, enable “Developer options” (if it is not already enabled), then go to “Select mock location app”, and finally select Bluetooth GNSS: that’s it, you have just authorized your phone to use the GPS information provided by Bluetooth GNSS!
Note: Depending on your Android version, you may notice slight differences in menu names or locations.
Then to perform the second and the third step, follow the plan below:
- Launch Bluetooth GNSS. You will then access the main screen.
- Open the “Settings” menu (top right)
- Select your external GPS from the “Target device” list (XGPS160-xxxxxx for the SkyPro XGPS 160)
- Deselect the “Secure RFCOMM connection” option and select the “Auto-reconnect” option
- Return to the main screen; you should see the five connection conditions met (Pre-connect checklist)
- To connect, press the connection button (blue button at the bottom right)
After a few seconds, the connection is made, and all the fields on the main screen are filled with the “new” GPS information from your external GPS! From this moment on, PerfectPower, like all the other applications on your smartphone that use GPS, will receive information from your external GPS (and only it!), until you choose to disconnect by pressing Disconnect/Stop in the menu at the top right.
You can then exit Bluetooth GNSS without worry, it will continue to run in the background and provide PerfectPower and all your GPS applications with information from your external GPS!