Page 1
Operational Description
ZigBee Endnode
The information in this document is subject to change
at the sole discretion of Timelox without notice.
Any use, operation or repair in contravention of this
document is at your own risk. Timelox does not assume
any responsibility for incidental or consequential
damages arising from the use of this document.
All information in this document is the property of
Timelox AB. Unauthorized use and reproduction is
prohibited. Copyright © 2012.
Page 2
Table of Contents
1. I
NTRODUCTION
1.1 Microprocessor.............................................................................................................................. 3
1.1.1 Reference Oscillator............................................................................................................... 3
1.2 Interfaces and Peripherals ............................................................................................................. 3
1.2.1 Background Debug Module ................................................................................................... 3
1.2.2 Communications Interface...................................................................................................... 3
1.2.3 LED........................................................................................................................................ 3
1.2.4 External Serial Memory ......................................................................................................... 3
1.2.5 Voltage Detector..................................................................................................................... 3
1.2.6 Battery Measurement.............................................................................................................. 3
1.3 Power Supply ................................................................................................................................ 4
1.4 RF Front-End................................................................................................................................. 4
1.4.1 Transceiver............................................................................................................................. 4
1.4.2 Rx/Tx Switch.......................................................................................................................... 4
1.4.3 LC Filter................................................................................................................................. 4
1.4.4 Antenna .................................................................................................................................. 4
1.5 Shield Box..................................................................................................................................... 4
........................................................................................................................3
© Timelox AB 2012
66 3081 050-0
2
Page 3
1. Introduction
This document details the operational description of the ZigBee endnode. The ZigBee endnode
is intended for proprietary, IEEE 802.15.4 and ZigBee WPAN (wireless personal area network).
The ZigBee endnode is based on the MC1321x family, i.e. Freescale’s second-generation ZigBee
platform which incorporates a low power 2.4 GHz transceiver and an 8-bit microcontroller into a
single LGA package.
1.1 Microprocessor
The MC1321x contains a microcontroller based on the HCS08 family of 8-bit MCU (microcontroller
units). The MC13213 has 60 KB of flash memory and 4 KB of RAM.
The MCU incorporates several functionalities such as UART, SPI, A/D converter, timer/pulse
width modulator, keyboard interrupts and a debug module.
1.1.1 Reference Oscillator
The ZigBee endnode includes a reference oscillator. The reference frequency is 16.000 MHz
with an accuracy below ±40 ppm over the entire operating temperature range.
1.2 Interfaces and Peripherals
This section provides an operational description for the peripherals and interfaces.
1.2.1 Background Debug Module
The ZigBee endnode includes a BDM (background debug module) interface. The BDM interface
to the MCU provides an interface for programming the on-chip memory. The BDM interface can
also be used for traditional debugging.
1.2.2 Communications Interface
The ZigBee endnode supports two serial interfaces that are selectable through firmware:
•
UART interface
•
I2C interface
1.2.3 LED
The ZigBee endnode includes a green LED. The functionality of the LED is application specific.
1.2.4 External Serial Memory
A serial memory acts as a storage for firmware images used during firmware upgrades of the MCU
(microcontroller unit) internal program flash. The serial memory enables bootloading of the endnode
firmware over air via SysMon (System Monitor; a maintenance software provided by Timelox) or
through direct connection to the communications interface. The serial memory can be entirely shut
off to conserve energy.
1.2.5 Voltage Detector
A voltage detector detects when the supply voltage goes below 2 V; if this is the case, a reset is made.
1.2.6 Battery Measurement
The endnode can measure the supply voltage through an external voltage divider that is controllable
via firmware.
© Timelox AB 2012
66 3081 050-0
3
Page 4
1.3 Power Supply
The ZigBee endnode includes a linear regulator with an output of 3 VDC to supply the entire device.
1.4 RF Front-End
This section provides a description of the RF front-end.
1.4.1 Transceiver
The MC1321x contains an RF transceiver which is an 802.15.4 standard compliant radio that
operates in the 2.4 GHz ISM frequency band. The transceiver includes a low noise amplifier, 1mW
nominal output power, PA with internal voltage controlled oscillator (VCO), on-board power supply
regulation and full spread-spectrum encoding and decoding.
An external LC-matching network steps the impedance down to 50Ω balanced and a small ceramic
balun allows the differential to single-ended transformation. A 50:50Ω balun is used.
1.4.2 Rx/Tx Switch
The ZigBee endnode includes a single pole double throw (SPDT) switch from NEC. The SPDT
switch has low insertion loss and high isolation. The Rx/Tx switch is controlled by the transceiver
and the Tx chain is active at a logic “0” and the Rx chain is active at a logic “0”.
1.4.3 LC Filter
The ZigBee endnode includes an LC filter for suppression of spurious harmonics. The LC filter
has a resonant frequency of approximately 2.80 GHz.
1.4.4 Antenna
The ZigBee endnode includes an integral PCB antenna. The PCB antenna is an inverted F-antenna
with a resonant frequency of approximately 2.45 GHz. The maximum antenna gain is 3.5 dBi.
1.5 Shield Box
The following items are covered by a grounded shield box:
•
microprocessor
•
transceiver
•
Rx/Tx switch
•
LC filter
•
Crystal
•
Voltage detector
© Timelox AB 2012
66 3081 050-0
4
Page 5
Revision history
Version Date Initials Description
0.0.1
2009-03-26 JJO
1.0.0 2009-03-27 JJO
Initiation of document
Release of document
2.0.0 2012-09-17 KG Revision for new endnode
© Timelox AB 2012
66 3081 050-0
5
Loading...