TEXAS INSTRUMENTS SWRU048 Technical data
User Manual
Rev. 1.2
CC2400DBK Demonstration Board Kit
SWRU048 Page 1 of 30
Table of contents
INTRODUCTION ....................................................................................................................... 3
PCB ........................................................................................................................................... 4
RF SECTION ............................................................................................................................ 4
ANTENNA ................................................................................................................................. 4
POWER SUPPLY SECTION.......................................................................................................... 7
RS-232 INTERFACE.................................................................................................................. 8
MICROCONTROLLER AND USER INTERFACE ................................................................................ 8
PCB LAYOUT ......................................................................................................................... 11
USING THE CC2400DB DEMONSTRATION BOARD.......................................................... 22
CC2400 SOFTWARE DOWNLOAD AND EVALUATION USING AVR STUDIO 4 ................................. 22
RC OSCILLATOR ..................................................................................................................... 23
MICROCONTROLLER EEPROM MAPPING................................................................................. 23
IN SYSTEM PROGRAMMING ..................................................................................................... 24
BOOTLOADER......................................................................................................................... 25
INTRODUCTION TO EXAMPLES PROVIDED WITH CC2400DB ...................................................... 26
SETTING UP A SOFTWARE PROJECT FOR CC2400 .................................................................... 27
HARDWARE DEFINITION FILES (HDF) ...................................................................................... 27
HARDWARE LIBRARY FILES (HLF)........................................................................................... 27
CONFIGURE OUTPUT PROFILE.................................................................................................. 28
DATA PACKET DESCRIPTION .................................................................................................... 28
DATA TRANSMISSION PROTOCOL ............................................................................................. 28
TROUBLESHOOTING............................................................................................................ 29
IT DOES NOT WORK................................................................................................................. 29
I CANNOT PROGRAM THE AVR USING THE SERIAL PORT ............................................................ 29
REFERENCES ........................................................................................................................ 29
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Introduction
The CC2400 single-chip RF transceiver provides a highly integrated, flexible low-cost solution
for applications using the world wide unlicensed 2.4 GHz frequency band. The CC2400DBK
demonstration board kit is a complement to the development kit (DK) as the hardware is
representative of an actual application, and it is well suited as a prototyping platform for
application code.
The CC2400DBK Demonstration Board Kit includes two CC2400DB Demonstration Boards.
These boards contain a CC2400 with necessary support components, an Atmel mega8 AVR
microcontroller, a PCB antenna, as well as a joystick, buttons and LEDs that can be used to
implement a visual user application interface. The demonstration board is also furnished with
connectors where all of the internal signals on the PCB are available.
This User Manual describes how to use the CC2400DBK Demonstration Board Kit. Atmel’s
AVR Studio and associated software is used to program and debug software. Please see the
reference section of this document for links to Atmel’s documentation on how to use their
tools.
Your CC2400DBK Demonstration Board Kit should contain the following items:
Kit contents
Item Number of articles
Demonstration Board (CC2400DB) 2
Quick Start instructions 1
CC2400 sample kit 1
RS-232 cables 2
Important:
Contact your local telecommunicat i on au thorities before transmitting an RF sig na l to ensure
that there are no local restrictions on the use of the 2400 –2483.5 MHz ISM ban d. The
CC2400 operates in the 2.4 GHz frequency b an d. Although this frequency band is usually
described as “world-wide”, some countries do not allow unlicensed operation in this ba nd .
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PCB
Figure 1 depicts an overview of the CC2400DB with description of the various components
embedded on the PCB.
RS-232
port
4-10 V
DC-jack
buttons
Optional 9V
battery
Joystick
MCU
section
Leds
PCB
antenna
CC2400 RF
section
3.3V voltage
regulator
1.8V voltage
regulator
Temp. sensor
Figure 1: CC2400DB overview
RF Section
The CC2400DB RF section includes all the necessary components for correct operation. The
CC2400 is connected to a 16 MHz crystal. A small 2.4 GHz PCB antenna is also included. RF
test and measurement equipment can be mounted the PCB by the use of an SMA connector,
by swapping capacitor placement of C63 and C62. See schematics for details. The RF layout
is identical to the CC2400EM, which is part of the CC2400DK Development Kit.
Important:
The CC2400DB demonstration board output power must be reduced for a 100% transmission
duty cycle to be compliant with the FCC 15 2
nd
harmonics regulation requirement. At the
moment the design is 1 dB above the limit.
Antenna
The PCB antenna is a so-called Inverted-F type. The Inverted-F antenna is a wire monopole
where the top section is folded down to be parallel with the ground plane. By folding the
antenna down you will reduce the height and maintain a resonant wire length. A capacitance
will be introduced to the input impedance of the antenna due to the parallel section. However,
as a rule of thumb design guide, the length + height (L+H) will be approximately equal to a
SWRU048 Page 4 of 30
quarter wavelength (λ/4). A reduction of the antenna height (H) will in general decrease the
antenna bandwidth. Please see figure 3 for the antenna dimensions.
Figure 2: Antenna dimensions
The height of the antenna is defined as the distance from the ground plane to the parallel
section, and the length is from the end of the antenna parallel section to the feed point.
Length: L = (26.19 mm – 9.19 mm + 1.22 mm x ½) = 17.61 mm
Height: H = (6.17 mm + 0.97 mm - 1.19 mm x ½) = 6.55 mm
Quarter wavelength: λ/4 = (L + H) = 17.61 mm + 6.55 mm = 24.16 mm
The physical size of the antenna is decreased somewhat compared to the theoretical length,
(λ = c/4*f = 3x10
8
/ 4x2.45x109) = 30.61 mm
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The radiated pattern for the PCB antenna was measured with the horizontal polarization
direction for the CC2400DB by measuring with vertical and horizontal mounting of the
demonstration board.
Important:
In practical range testing outdoors wi th line-of-sight (LOS) and use of the rf BlinkLed
application example, the f ollowing range has been verified at Chip con Norwa y with optimal
SmartRF Studio settings for the respective data rates:
1. Data rate settings 1 Mbps, range measured: 140 meters
2. Data rate settings 250 kbps, range measured: 240 meters
Please note that these range test s were performed at 0
°
C with a simple packet protocol, no
link margin, no robust protocol, close to the sensitivity limit of CC2400, and no retransmission.
0 degr.
Antenna
CC2400DB
Top view
Figure 3: Radiated pattern horizontal mounting
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Figure 3 depicts the antenna pattern while the CC2400DB is mounted horizontally with the
antennas parallel section aligned to the 0 degree direction.
0 degr.
Antenna
CC2400DB
Top view
Figure 4: Radiated antenna pattern vertical mounting
Figure 4 depicts the antenna pattern while the CC2400DB is mounted vertically with the
antennas parallel section aligned to the 0 degree direction.
Power supply section
The power supply section contains two voltage regulators: a 3.3 V regulator for use by the
microcontroller and the I/O pins of the CC2400, and a 1.8 V regulator for powering the
CC2400 core.
A diode prevents permanent damage if wrong polarity is applied to the board. There are two
power connectors; a 2.5mm DC jack-type connector allows you to connect an unregulated
battery eliminator easily (the positive supply is on the center pin), and a connector for a 9V
battery on the bottoms side of the PCB. It is also possible to use 3 or 4 AA or AAA alkaline
cells to power the CC2400DB if a suitable battery pack is used.
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RS-232 interface
A serial port is included on the CC2400DB. This port is used when software is programmed
into the AVR MCU using the boot loader, and is also used by several of the example
programs. The port includes support for RTS/CTS-type hardware flow control (handshaking).
Important:
It is important to be aware that maximum data rate for the A tmega8 RS-232 interface on
CC2400DB is 38.4 Kbps due to the use of the internal RC oscillator. Please see th e Atmega8
datasheet for a baud rate error overview with the respect to a selected oscillator freq ue ncy.
Microcontroller and user interface
The microcontroller used is an AVR Atmega8L from Atmel. This controller has 8 KB of Flash
program memory, 1 KB of SRAM data memory and 512 bytes of non-volatile EEPROM data
memory. The controller runs on its internal oscillator, and is interfaced to the CC2400 via its
built-in SPI interface as well as some general I/O pins.
The MCU is also connected to three LEDs, a joystick and an extra button for user interface
purposes. The different examples use these peripherals differently. An analog temperature
sensor is also included.
An ISP connector is provided for programming the AVR without using the serial port. In this
case an Atmel AVR programmer should be connected to this connector.
All of the I/O pins are connected to footprints for 2 x 10 pin-row connectors. These connectors
are compatible with Agilent logic analyzer probes, and can be used either for testing or for
prototyping. For instance, it is possible to add a daughter board with additional circuitry using
these connectors.
AVR Pin
AVR pin name Pin usage I/O connector
Number
1 PD3/INT1 CC2400 DIO/DKT P4 pin 14
2 PD4/XCK/T0 Yellow LED P4 pin 7
7 PB6/XTAL1/TOSC1 Joystick up P3 pin 9
8 PB7/XTAL2/TOSC2 Joystick right P3 pin 7
9 PD5/T1 Joystick down P3 pin 6
10 PD6/AIN0 Joystick left P3 pin 3
11 PD7/AIN1 Joystick center push P3 pin 5
12 PB0/ICP RS-232 handshaking RTS, push
P3 pin 13
button
13 PB1/OC1A RS-232 handshaking CTS, Red LED P3 pin 17
14 PB2/SS/OC1B CC2400 chip select P4 pin 13
15 PB3/MOSI/OC2 CC2400 SI, AVR ISP P4 pin 8
16 PB4/MISO CC2400 SO, AVR ISP P4 pin 6
17 PB5/SCK CC2400 SCK, AVR ISP P4 pin 4
19 ADC6 Not used P4 pin 11
22 ADC7 Temperature sensor P4 pin 9
23 PC0/ADC0 CC2400 GIO6 P4 pin 10
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24 PC1/ADC1 CC2400 GIO1 P4 pin 19
25 PC2/ADC2 CC2400 TX P4 pin 16
26 PC3/ADC3 CC2400 RX P4 pin 18
27 PC4/ADC4/SDA RS-232 on/off P3 pin 11
28 PC5/ADC5/SCL Green LED P4 pin 5
29 PC6/RESET Reset button, AVR ISP P4 pin 3
30 PD0/RXD RS-232 receive data from PC P3 pin 15
31 PD1/TXD RS-232 transmit data to PC P3 pin 19
32 PD2/INT0 CC2400 DCLK/FIFO P4 pin 12
Table 1: AVR I/O pins
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