Page 63 - Build Your Own Quadcopter_ Power Up Your Designs with the Parallax Elev-8

42 Bu il d Y o ur O w n Q u a d c o p t e r

makes it very easy to tap into the battery supply in order to power an accessory circuit or
module. There is also a two-pin plug available for devices that use this common type of
power supply connector.
A power-distribution cable harness is shown in Figure 3.12. It serves the same purpose
as the quad power-distribution board but uses a premade harness that would be similar to
the homemade one discussed above. Using the cable harness keeps the battery supply totally
shielded; however, you would have no access to it without splicing into the harness.
I will be using a quad power-distribution board that I purchased from Hobbyking. The
additional EC3 connectors will be used to connect the motors and extension wires. It is a
process that is a bit more tedious; however, it makes for more sturdy and reliable connections.
The additional red and black 22 AWG wire will be needed to connect the LED lighting
strips to the auxiliary Propeller-chip control board for light-control purposes. There will also
be plenty of wire remaining for any circuits or modules that you might desire to add at a
later date.

Functionally Related Material
• Spektrum TM1000 telemetry transmitter
• Spektrum telemetry brushless r/min sensor

The Spektrum TM1000 telemetry transmitter shown in Figure 3.13 sends data from the
quadcopter back to the DX-8. It also comes with voltage and temperature sensors that can
send real-time data back to the DX-8 for the voltage and temperature of a selected component
to be monitored. I will use this module to monitor both the raw battery voltage and the
battery temperature. The DX-8, in spite of being labeled an R/C transmitter, also contains a
telemetry receiver. The data being sent back may be displayed on the DX-8 LCD screen,
which is another reason to buy the DX-8.
The Spektrum telemetry brushless r/min sensor is shown in Figure 3.14. This sensor will
be used to monitor the rotational speed of one of the Elev-8 motors. It will provide useful
data when you are creating a new flight-control program and will also serve as a check on
the real-time performance of the quadcopter.

Figure 3.12 Power-distribution cable harness.