AVR2016: RZRAVEN Hardware User's Guide
Features
• Development kit for the AT86RF230 radio transceiver and AVR® microcontroller.
• CE, ETSI and FCC approved.
• LCD module (AVRRAVEN):
- AT86RF230 radio transceiver with high gain PCB antenna.
- Dual AVR microcontrollers.
- Dynamic Speaker and microphone.
- Atmel Serial Dataflash®.
- User IO section:
• USART
• GPIO
• Relay Driver
- Powered by battery or external supply:
• 5V to 12V external supply.
• USB module (RZUSBSTICK):
- AT86RF230 radio transceiver with miniature PCB antenna.
- AVR microcontroller with integrated Full Speed USB interface.
- External memory interface.
1 Introduction
8-bit
Microcontrollers
Application Note
The RZRAVEN is a development kit for the AT86RF230 radio transceiver and the
AVR microcontroller. It serves as a versatile and professional platform for
developing and debugging a wide range of RF applications; spanning from: simple
point-to-point communication through full blown sensor networks with numerous
nodes running complex communication stacks. On top of this, the kit provides a
nice human interface, which spans from PC connectivity, through LCD and audio
input and output.
Figure 1-1. The RZRAVEN Kit Modules
Rev. 8117D-AVR-04/08
2 General
The RZRAVEN kit is built from one RZUSBSTICK module and two AVRRAVEN
modules. See
The complete schematics and Gerber files are available from the compressed archive
accompanying this application note.
Figure 2-1 Assembly drawing AVRRAVEN - front view.
Figure 2-1 to Figure 2-4 for further details.
Figure 2-2 Assembly drawing AVRRAVEN - back view.
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Figure 2-3 Assembly drawing RZUSBSTICK - front view.
Figure 2-4 Assembly drawing RZUSBSTICK - back view
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3 The AVRRAVEN Module
Figure 3-1 AVRRAVEN overview
Joystick
and user
I/O
MCU #1:
ATmega3290P,
User I/O
Realtime
Clock oscillator
32kHz Xtal
The AVRRAVEN hardware is based on 2 microcontroller and one radio transceiver
chip. The ATmega3290P handles the sensors and the user interface and the
ATmega1284P handles the AT86RF230 radio transceiver and the RF protocol stacks.
The MCUs and the radio communicate via serial interfaces.
For hardware details please refer to Appendix A for the complete AVRRAVEN
schematics.
Audio
I/O
On-chip MCU
RC oscillator,
Set to 4MHz
LCD
display
2-way async
Serial comm
MCU #2:
ATmega1284P,
RF Stacks
Realtime
Clock oscillator
32kHz Xtal
On-chip MCU
RC oscillator,
Set to 4MHz
2-way sync
Serial comm
PCB Antenna
Radio chip
AT86RF230
16MHz Xtal
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3.1 AVR Microcontrollers
Two AVR microcontrollers are found on the AVRRAVEN module. An ATmega1284P
is connected to the AT86RF230 radio transceiver, and an ATmega3290P is driving
the LCD. Both these devices are selected from the AVR picoPower family, something
that ensures minimal power consumption and operation down to 1.8 Volts. Universal
Synchronous and Asynchronous serial Receiver and Transmitter (USART) is used as
an inter processor communication bus.
3.2 Atmel Radio Transceiver
The AT86RF230 is a 2.4GHz radio transceiver that is tailored for a wide range of
wireless applications. Low power consumption and market leading RF performance
makes it an excellent choice for virtually any type of networking device. Support for
IEEE 802.15.4
channel access) type of applications is available through an enhanced layer of
functionality on top of the basic radio transceiver.
3.3 Antenna description
The antenna on the AVRRAVEN is a 100 loop antenna with a net peak gain of
about 5dB.
3.4 LCD
TM
(Automatic acknowledge of packets, address filtering and automatic
The LCD found on the AVRRAVEN module is a full custom 160-segment display
tailored for the RZRAVEN kit (See
segments text area; four segment number area and numerous handy symbols. In
particular pay attention to the bird looking symbol. It is symbolizing the two black
scouting ravens of Norse god Odin; Hugin (Thought) and Munin (Memory). The saga
says that they flew around the world and reported news back to Odin at night.
Underneath the raven segment’s “eye” there is a red LED capable of soft-blinking;
this may be used to indicate the AVRRAVEN’s search for “news” on the air interface.
A full segment map can be found in Appendix C and in the schematics folder in the
compressed archive file accompanying this application note. The LCD is driven
directly from the connected ATmega3290P.
Figure 3-2 AVRRAVEN - LCD Segments
Figure 3-2 for a quick reference). It contains a 7
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3.5 Speaker
3.6 Microphone
3.7 Serial Dataflash®
An 8 speaker is provided. The ATmega3290P controls all audio. The signal source
is the TIMER1’s PWM output and the signal is shaped via a low-pass filter and
amplified by a Class-D amplifier. Pulling PORTE7 low activates the active filter and
providing a PWM signal on PORTB5 activates the amplifier.
The AVRRAVEN’s microphone is connected to the ATmega3290P ADC channel 0.
The signal is amplified and low-pass filtered. Pulling PORTE7 low activates the
microphone circuit.
A 16-Mbits Atmel Serial Dataflash (AT45DB161D) is connected to the
ATmega3290P’s Serial Peripheral Interface (SPI). This storage is used for safe
firmware images, sounds and general-purpose parameters. See the firmware
documentation for an overview of occupied sectors, and those available to the end
user. Even with a couple of safe firmware images for the two microcontrollers there is
plenty space left for the end user. Please note that the serial Dataflash will operate
properly when the voltage is above 2.5 Volts while the rest of the design will operate
down to 1.8Volts
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3.8 Serial EEPROM
3.9 Real Time Clock
3.10 NTC
A 2-Kbits Atmel Serial EEPROM (AT24C02B) is connected to the ATmega1284P’s
two-wire interface (TWI). This storage is write protected by hardware and can only be
read. The storage contains important configuration and calibration data that should
not be unintentionally overwritten. Information such as a unique EUI 64-bit address
can be found her-in. A rich set of access functions and the parameter map is given in
the RZRAVEN firmware documentation.
Separate 32768 Hz clock crystals are connected to the ATmega3290P’s and the
ATmega1284P’s asynchronous timer interfaces. This allows an application to
implement a real time clock (RTC) to keep track of time when sleep modes are used
to reduce the power consumption. This is especially important for battery-operated
nodes.
A NTC is connected to the ATmega3290P’s Analog to Digital Converter (ADC)
channel 4. This NTC can be used to measure the temperature in the surroundings of
the AVRRAVEN. The NTC can be found below the joystick, close to J401. The JTAG
interface must be disabled when using the temperature sensor. When running the
AVRRAVEN from an external power source the onboard voltage regulator may heat
the temperature sensor giving faulty reading. To avoid this the sensor NTC may be
soldered off and relocated using short wires. If a higher level of accuracy is required
the users may also calibrate the sensor by adjusting the temperature lookup table in
firmware.
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3.11 Power Supply
The AVRRAVEN can be powered either from batteries or an external 5 to 12 Volts
DC source. The power source is selected by the position of the jumper located
immediately to the right of the LCD (See the figure below for a reference). Polarity
protection is provided when using an external power source.
The AVRRAVEN has been designed to run from two 1.5V LR44 battery cells.
An onboard voltage regulator makes it possible to run power the AVRRAVEN from a
5 to 12 Volts DC source. The external voltage is applied to the two leftmost pins in the
user IO area (J401). The ATmega3290P’s ADC channel 2 is connected to a voltage
divider and the external voltage supply interface. This way it is possible for the
application to monitor the external operating voltage.
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3.12 Interfaces
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The AVRRAVEN module has multiple interfaces that can be used for serial
communication, interaction with external sensors and control units such as relays and
of course programming and debugging.
Figure 3-3 AVRRAVEN User Interfaces
Table 3-1
Pin number Function Comment
1 Ext. power supply, 5-12V input External power input
2 Ext. power supply 0V Connected to internal 0V
3 Relay coil positive Relay driver circuit positive
4 Relay coil negative Relay driver circuit negative
5 Voltage measure input, 0-Vcc*5 Analog input via 47k/10k voltage divider
6 Voltage measure input, 0-Vcc Analog input directly to ADC input.
7 Vcc Connected to the VCC net directly
8 User IO #1
9 User IO #2
10 User IO #3
11 User IO #4
12 Common Connected to internal 0V
. Interfaces available on J401
Digital I/O, may interface an LED or a
switch directly. On-board 470 series
resistors and 10k pull-ups are provided.
Pin change interrupts, TWI and USI is
also available on these pins.
Care should be taken when connecting to the AVRRAVEN’s interfaces, since there is
no protection circuitry provided. Damage to the MCUs or other circuits may be the
result of ESD spark, short circuits, polarity or over-voltage faults.
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3.12.1 Programming Interface
Both the ATmega3290P and ATmega1284P can be programmed using either the
JTAG or ISP interface. JTAG programming can be facilitated by connecting a JTAG
ICE mkII to the 50-mil pin header J301 (ATmega3290P) and J204 (ATmega1284P). A
total of 5 50-mil pin headers and one 50-mil to 100-mil converter are supplied with the
RZRAVEN kit.
ISP programming can be performed by connecting an ISP enabled AVR programming
tool to the pin header J302 (ATmega3290P) and J205 (ATmega1284P). AVR tools
like STK500, AVRISP mkII and JTAGICE mkII can be used for this.
The AVRRAVEN does not come with these headers mounted. So it is up to the user
populating these. Wires could also be soldered in instead of the dual row headers.
3.12.2 Relay Interface
A relay interface (Relay Positive and Negative) is available through J401. This
interface can be used with the AVRRAVEN running from external power. A switching
transistor is connected to PB6 on the ATmega3290P so that sufficient current can be
provided to the relay being driven. An external power source must be used if the relay
option is required. The AVRRAVEN must then be supplied with the rated voltage of
the relay.
3.13 Voltage Measurement Interface
3.13.1 GPIO
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Two of the pins in header J401 can be used for external voltage measurements,
however only one at the time. The possible voltage ranges are 0 to VCC or via a
voltage divider giving an approximate range of 0 to five times VCC. A simple voltage
divider is implemented to scale the measurement voltage. A diode bridge is also used
to prevent reverse polarity and to protect the ATmega3290P’s ADC channel 3.
Both the ATmega3290P and ATmega1284P are high pin count devices, and a
number of these are not used. These pins are available through the user IO headers;
J401, J201, J202 and J203. See
Table 3-2 and Table 3-3 for further details.
Be aware that these pins do not have level converters and should thus not be
connected directly to an application board running on a different voltage level than the
AVRRAVEN.
Table 3-2
ATmega3290P Port Pin PCB Connection Comment
PE3 J401 –8
PE4 J401-9
PE5 J401-10
PE6 J401-11
. ATmega3290P User IO
Via 470 series resistor
and10k pull-up
Via 470 series resistor
and10k pull-up
Via 470 series resistor
and10k pull-up
Via 470 series resistor
and10k pull-up
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Table 3-3. ATmega1284P User IO
ATmega1284P Port Pin PCB Connection Comment
PC0 J201-1
PC1 J201-2
PC2 J201-3 JTAG TCK.
PC3 J201-4 JTAG TMS.
PC4 J201-5 JTAG TDO.
PC5 J201-6 JTAG TDI.
N.C. J201-7
N.C. J201-8
PD0 J202-1
PD1 J202-2
PD2 J202-3 DIO or RXD1.
PD3 J202-4 DIO or TXD1.
PD4 J202-5 DIO.
PD5 J202-6 DIO.
PB2 J202-7 DIO. NB: NOT PD6!
PD7 J202-8 DIO.
PA0 J203-1 DIO or ADC Channel 0.
PA1 J203-2 DIO or ADC Channel 1.
PA2 J203-3 DIO or ADC Channel 2.
PA3 J203-4 DIO or ADC Channel 3.
PA4 J203-5 DIO or ADC Channel 4.
PA5 J203-6 DIO or ADC Channel 5.
PA6 J203-7 DIO or ADC Channel 6.
PA7 J203-8 DIO or ADC Channel 7.
Additional interfaces PCB Connection Comment
External power J201-10
J202-10
J203-10
0V J201-9
J202-9
J203-9
TWI SCL.
Connected to serial EEPROM
TWI SDA.
Connected to serial EEPROM
Populate R204 to connect to
PC6. RTC Xtal XC202 must
then be removed.
Populate R205 to connect to
PC6. RTC Xtal XC202 must
then be removed.
RXD0 Inter processor
communication.
TXD0 Inter processor
communication.
Connected to J401-1
Connected to J401-2
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