The BTnode rev3 is a dual radio device compatible to the old BTnode rev2 and the Berkeley Motes. This twin device can operate both radios simultaneously or shut them down independently when not in use. Both the BTnut System Software and TinyOS are supported.
New features for the BTnode rev3 are a new Zeevo ZV4002 Bluetooth system supporting up to 4 independent Piconets and 7 Slaves and an additional Chipcon CC1000 low-power radio. The system is built around an Atmel ATmega128l microcontroller with an integrated battery case to house 2xAA cells and extension connectors. The BTnode is built on a 4 layer PCB measuring 58.15x32.5mm.
The hardware is scheduled for sample availability by the end of Q3/2004 and volume availability through a contract manufacturer thereafter. Pricing will be about USD 200 for samples.
The BTnode System Core consists of an Atmel ATmega128L microcontroller, clocks and SRAM memory.
Zeevo ZV4002 Bluetooth radio running HCI firmware.
The radio is power class 2, without an external power amplifier.
It supports the following features: Features: 0xff 0xff 0x05 0xf8 0x1b 0x18 0x00 0x80 <3-slot packets> <5-slot packets>
Chipcon CC1000 radio operating at 868 MHz. Other operating frequencies can be used according to the CC1000 documentation (433-915 MHz). Both an integrated monopole antenna, and external wire and an external coaxial connector (MMCX type) are possible. The default assemply variant is the internal antenna.
The standard power supply are 2-cell AA batteries. The common range for these is 2-3V DC when either primary or rechargeable batteries are used. The primary boost converter has an input range of 0.5-3.3V DC. Alternatively 3.8-5V can be supplied through the VDC_IN pin on the external connectors J1 and J2.
|BTnode rev3 Bluetootha||BTnode rev3 Low Power Radioa|
|Battery Supply||2 AA cells|
|Minimum Vin||0.85 V|
|Battery Capacity||2900 mAh|
|CPU sleep, Radio off||9.9 mW||9.9 mW|
|CPU on, Radio off||39.6 mW||39.6mW|
|CPU on, Radio listen||92.4 mW||82.5 mW|
|CPU on, Radio RX/TX||105.6 mW||102.3 mW|
|CPU on, Bluetooth Inq||198 mW||--|
|CPU on, Radios both listening||135.3 mW|
|Max. Power||198 mW||102.3 mW|
External Interfaces UART, SPI, I2C, GPIO, ADC, Clock, Timer, LEDs
There are two ways to physically connect to a BTnode. The extension connector J1, or the debug connector J2. Both types are available at Farnell or Digikey in small quantities (Molex 1.25mm Wire-to-Board and Hirose DF17 Board-to-Board connectors)
Extension Connector J1 Hirose Receptacle DF17-40DS
Debug Connector J2 Molex 53261-1590
Mating with Molex 51021-1500 connector housing
available at Farnell under item no. 615171
available at Digikey under item no. WM17002-ND. Suitable plug connectors are available at Farnell under item no. 889570
Assembly Top View
The recommended fuse bit settings for the ATmega128l are
Fuses are logical one if selected OFF and zero if selected ON. For optimal power consumption results, fuses need to be adapted in the final application (see Atmel ATmega128l datasheet for information). We recommend to turn off OCDEN and JTAGEN at a minimum.
The devices up to BTnode rev3.22 have a hardware error in the ISP programming logic. It is easy to fix and increases the reliability of ISP programming. All users that use ISP programming should implement this patch as described to prevent their devices from ISP programming failures.
The patch adds a 10k Ohm resistor R14 in the SCK line decoupling the CC1000 radio from the ISP programming logic of the AVR. This is especially an issue when the CC1000 radio is not powered (possibly at bootup) and the SCK signal coming from the ISP programming device is then running into both the AVR and the unpowered input pin on the CC1000.
To install the resistor lift up the SCK pin on the CC1000 and add a 0402 size 10K Ohm resistor R14 under the pin. It's the 5th from the right: