Eagle Tree Car Data Recorder - Manual (Page 4)

Copyright © 2003 Eagle Tree Systems, LLC
http://www.eagletreesystems.com
Page 4
Several of our customers have been able to use existing RPM sensors, such as governors or turbine sensors, with our
products. The following steps must be followed:
1) Determine the “pinout” of the existing sensor. Compatible sensors will have Power, Ground, and Signal connections. The
Recorder’s RPM pinout, from left to right, is: Power (black wire), Ground (red wire), Signal (white wire).
2) Devise a “Y” cable to connect your existing sensor to it’s connection, and also to the Recorder’s RPM connection. NOTE:
Power for the sensor should come only from the connection the sensor is normally plugged into. So, only Gound and Signal
wires should be routed from the existing sensor to the recorder. The power wire of the Y cable between the sensor and the
recorder should be cut before connecting it to the recorder. This is necessary to avoid connecting the power of the existing
sensor connection to the Recorder’s power connection.
3) Thoroughly test the system to make sure the sensor still works with whatever it was originally connected to, after Y’ing to the
recorder.
Installing a Secondary RPM Sensor
A second MODIFIED RPM sensor can be plugged into the unused servo port nearest the switch on the recorder, for measuring wheel
slip or other parameters. This RPM sensor must be modified by swapping the red and black wires in the RPM sensor plug.
Carefully pry back the plastic tabs that hold each pin in the plug, remove the red and black pins, and re-install them so that the pin
order is RED, BLACK, WHITE. The second RPM sensor plugs into the servo port with the red wire to the right, nearest the edge of
the recorder.
NOTE: for the secondary RPM sensor to work, there has to be voltage from 4.5 to 6.5 V supplied to one or both of the servo inputs (as
shown in Figure 1). This is normally done with the Y Cables, a separate battery, or your BEC.
The second RPM channel is set up in the “Secondary RPM Sensor Setup” section under “Tools, Calibrate Speed from RPM.”
Normally, if the second RPM is used for wheel speed, just enter a “1” in this field if you are using 2 magnets, or a “2” if you are using
only one magnet.
The secondary RPM sensor is logged and displayed on the screens with the other parameters, as described below.
Installing the Optional Battery Backup Harness
In most cases, the Recorder can be successfully powered by the Y cables from the receiver. If you have problems with recorder
power during acceleration or steering, as described in the troubleshooting section, this can be remedied by adding a small backup
battery to power the recorder. To add the backup battery, plug the larger end of the optional backup harness into the recorder. The
backup harness is a two wire cable with a Futaba style male connector on one end, and a larger male connector on the other end.
The large end of the backup harness plugs into the USB port of the recorder, with the red wire in the same place as the red wire of the
USB cable (as shown in the drawing).
The backup battery must be at least 4.5volts to power the recorder. Power is only drawn from the backup battery when the voltage
being supplied through the Y cables drops below the voltage of the backup battery, so if you use a 4.5 volt backup battery, no power
should be drawn from it except for moments when the main battery drops below this voltage. Therefore, it is possible to use a very
small pack (a tiny 4 cell pack or possibly 3 watch type batteries) as the backup battery. Note of course that the backup battery must
be disconnected whenever the receiver is turned off, as it will power the recorder whenever power is not supplied to the recorder from
the receiver. If you want to get fancy, you could add a DPDT switch in place of the standard receiver switch and turn off the backup
battery whenever you turn off the receiver.
Removing the Recorder from your Car
When you remove the Recorder, your servos are still connected to your receiver so it’s not necessary to remove the ‘Y’ cables from
the car to operate it without the Recorder. Be sure however that the connectors are kept from shorting.
Note: Additional ‘Y’ cables, RPM sensors and temperature sensors are available for purchase on our website if you wish to install
and leave ‘Y’ cables in more than one car. This makes it very easy to use the same recorder with multiple cars.
Installation and Use of the Windows™ Application
Installing the Windows Application