iOS Sensor Apps with Arduino

Connecting Directly to the Cable

Because the EZ1 has an RS-232 connection, it’s actually possible to connect it directly to the Redpark cable without using the Arduino board at all. The Redpark Serial Cable is wired in a standard fashion, terminating with a male DB-9 connector; the pin out for this connector is shown in Figure 4-11 and described in Table 4-1.

Figure 4-11. The Redpark Serial cable DB-9 connector

Table 4-1. The Redpark Serial Cable DB-9 (male) Connector Pin Out

Pin Number	Function	I/O	Description
1	DCD	I	Data carrier detect
2	RX	I	Receive
3	TX	O	Transmit
4	DTR	O	Data terminal ready
5	GND	-	Ground
6	DSR	I	Data set ready
7	RTS	O	Request to send
8	CTS	I	Clear to send
9	RI	I	Ring indicator

Comparing Figure 4-1 and Figure 4-11, we’ll need to wire up only 3 of the 9 available pins: GND, RX, and TX. Taking a female DB-9 connector, you should therefore wire it as in Figure 4-12. Comparing Figure 4-11 and Figure 4-12, you should notice that in the female connector, we wire pin 2 to TX and pin 3 to RX. This means that TX from the EZ1 is connected to RX on the cable, and vice versa.

Figure 4-12. Pin wiring for the LV-MaxSonar-EZ1 connecting to DB9 (female)

After wiring this cable, go ahead and solder a header block onto the EZ1 sensor board (see Figure 4-13).

Figure 4-13. Header block soldered to the EZ1 sensor

When wiring the ...