User's Manual

V3d Product Specification, Version 2.06
3.2.3.3 Operating Scenario
A planned future capability of the V3d includes networking with other V3d’s using ZigBee
protocols
1
. Local star networks inside each shipping container connect to a large mesh network
outside. The coordinators assign themselves when an outside network is available, for example
the top container in a stack. The "routers" (other V3d’s without an outside network)
automatically connect to an accessible coordinator through other routers or directly.
The local area network, consisting of multiple sensors (end nodes) and a single V3d (router /
coordinator), runs on a 4 minute beacon with a wake time of 15 ms per 4 minutes. Outside of
the container, the overall mesh network linking nearby V3d devices is activated twice per day at
12 noon and 12 midnight UTC. The network is to remain powered and active for up to 1 minute
to allow for network enumeration and data transmission. The 1 minute requirement is based on
worse case RTC drift over a maximum 7 day period where a V3d device may not be able to
receive timing information from either GPS or ORBCOMM signals.
3.2.3.4 Ember ZigBee
The V3d is to use the Ember EM250 ZigBee chipset. The V3d is to employ a 28-pin Samtec
connector, identical to the Ember development kit, except with fewer active pins (detailed in
table below). This is expected to enable use of a number of Ember modules from various
manufacturers, including Ember’s own control module supplied with their development kit
2
.
Application level control and management is provided through the pins / circuits between the
ZigBee controller and the V3d Blackfin / MCU. The EM250 GPIO9 and GPIO10 are required
connections for serial communication. Of the four remaining pin connections, one of them needs
to be used to wake up the DSP from the ZigBee module. Another pin needs to be used to wake
up the ZigBee module from the DSP side. The last two pin connections are reserved for future
use and should have test points to make it easier to jumper if needed.
EM250 Pin Name Function Application
32 GPIO 9 TXD (UART transmit data on
Serial Controller 1)
For connection to Blackfin serial
port UART RX
33 GPIO 10 RXD (UART receive data on
Serial Controller 1)
For connection to Blackfin serial
port UART TX
31 GPIO 8 IRQ_A Wake signal, EM250 to Blackfin
42 GPIO 14 IRQ_B Wake signal, Blackfin to EM250
41 GPIO 15 IRQ_C Future
40 GPIO 16 IRQ_D Future
2
The Ember control module supplied with the Ember development kit is expected to be useful
only for software development and test and not production.
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