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M2x40 Mote Datasheet Dust Networks™ 11
Figure 6 Operation of Time Pin
8.2 Status LED
¯¯¯
Signal
The M2x40 provides an output that can be used to drive a status LED
¯¯¯
. This signal indicates network connectivity information
which is most useful during mote installation. Alternatively, the mote’s network status may be polled via serial using the Get
Parameter request with the mote state parameter (see section Mote Serial API Guide).
Table 11 Status LED
¯¯¯
Signal
LED
¯¯¯
Signal Behavior
Mote State
High Off, or in sleep mode
Single blink (750 ms low, 3 s high) On, and searching for potential network
Double blink (750 ms low, 750 ms high, 750 ms low, 3 s
high)
On, and attempting to join the network
Triple blink (750 ms low, 750 ms high, 750 ms low, 750 ms
high, 750 ms low, 3 s high)
On, and attempting to establish redundant links
Low
On, fully configured into network with redundant
parents
8.3 Serial Interface
8.3.1 Serial Interface Overview
The M2x40 offers a well-defined five-signal serial interface that is optimized for low-powered embedded applications. This
serial interface offers a serial port comprised of the data pins (TX, RX) as well as handshake pins (MT_RTS
¯¯¯¯¯¯¯
, MT_CTS
¯¯¯¯¯¯¯
,
SP_CTS
¯¯¯¯¯¯¯
) used for bidirectional flow control. Through this port, the M2x40 provides a means of transmitting and receiving
serial data through the wireless network, as well as a command interface that provides synchronized time stamping, local
configuration, and diagnostics.
The serial handshake provides for flow control of packets transmitted via the M2x40 serial interface. Packet delineation and
error control are handled separately. The handshake supports the following:
• Full-duplex communication
• Bidirectional byte-level flow control
The five-signal serial port is comprised of the data pins (TX, RX) as well as the handshake pins (MT_RTS
¯¯¯¯¯¯¯
,MT_CTS
¯¯¯¯¯¯¯
,
SP_CTS
¯¯¯¯¯¯¯
) used for bidirectional flow control. This port supports 9600 bps operation in full-duplex mode. The handshake
signals are active low.
Table 12 Mode 1 and Mode 3 Serial Parameters
Parameter Mode 1 Mode 3
Serial
Control signals 5-signal 5-signal
Flow control Bidirectional Bidirectional
Bit rate 9600 bps 115.2 kbps