Page 179 - Build Your Own Quadcopter_ Power Up Your Designs with the Parallax Elev-8

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

Figure 6.27 The X-BUS High Current sensor.

more than one sensor is to be used at the same time. Figure 6.27 shows the High Current
sensor with the two X-BUS sockets shown on the sensor body. Also, notice that this sensor
already comes equipped with EC-3 connectors, which make the connection to the LiPo
battery very easy if you use that type of connector.
Spektrum has not published any information regarding the X-BUS; however, it is
2
reported to be an I C bus as a result of some clever reverse engineering by an R/C aficionado.
This bus uses a minimum of three wires, while Spektrum adds another one for some
additional functions. The four connections are:

1. SDA—Serial data
2. SCL—Clock line
3. UBatt—Proprietary Spektrum function
4. GND—Ground

The Inter-Integrated Circuit interface or I C (pronounced eye-two-cee or eye-squared-
2
cee) is also a synchronous serial data link. Figure 6.28 is a block diagram of the I C interface
2

Figure 6.28 The I C block diagram.
2