Microchip Technology A091619 User Manual

Atme l-42097B-WIRELESS-AT02876-REB212BSMA-Hardware-User-Manual_ApplicationNote_062014

APPLICATION NOTE

AT02876: Atmel REB212BSMA Hardware User Manual

Atmel MCU Wireless

Introduction

This manual describes the REB212BSMA radio extender board, demonstrating the high performance at ultra-low power consumption of the Atmel radio transceiver.

AT86RF212B

Features

• High-performance 700/800/900MHz, RF-CMOS AT86RF212B radio transceiver

targeted for ZigBee

– 121dB link budget – Ultra-low current consumption – Ultra-low supply voltage (1.8V to 3.6V)

• RF reference design and high-performance evaluation platform

• Interfaces to several of the Atmel microcontroller development platforms

• Board information EEPROM

– MAC address – Board identification, features, and serial number – Crystal calibration values

, IEEE® 802.15.4, 6LoWPAN, and ISM Applications

1 Introduction

This manual describes the REB212BSMA radio extender board, demonstrating the high performance at ultra-low power consumption of the Atmel AT86RF212B radio transceiver. Detailed information is given in the individual sections about the board functionality, the board interfaces, and the board design.

The REB212BSMA connects directly to the REB controller base board (REB-CBB) [2], or can be used as an RF interface in combination with one of the Atmel microcontroller development platforms. The REB212BSMA together with a microcontroller forms a fully functional wireless node.

Figure 1-1. REB212BSMA Radio Extender Board

2 Disclaimer

Typical values contained in this application note are based on simulations and testing of individual examples.

Any information about third-party materials or parts was included in this document for convenience. The vendor may have changed the information that has been published. Check the individual vendor information for the latest changes.

3 Overview

The radio extender board is assembled with an Atmel AT86RF212B radio transceiver [1] and equipped with an SMA connector for an external whip antenna. External antennas can be connected to the SMA ports as well as RF measurement equipment for performance evaluation of the radio transceiver.

The radio extender board was designed to interface to the Atmel microcontroller development or evaluation platforms (for example, Atmel STK ideal way to:

• Evaluate the outstanding radio transceiver performance, such as the excellent receiver sensitivity

achieved at ultra-low current consumption

• Test the radio transceiver’s comprehensive hardware support of the IEEE 802.15.4-2011 standard

• Test the radio transceiver’s enhanced feature set, which includes MAC hardware acceleration, AES

encryption and high data rate modes

500). The microcontroller platform in combination with the REB provides an

AT02876: Atmel REB212BSMA Hardware User Manual [APPLICATION NOTE]

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Figure 3-1 shows a development and evaluation setup using the REB controller base board (REB-CBB) in

combination with the REB212BSMA radio extender board; via SMA connector which is assembled with quarter wave whip antenna.

Figure 3-1. The REB212BSMA Connected to a REB-CBB

4 Functional Description

The block diagram of the REB212BSMA radio extender board is shown in Figure 4-1. The power supply pins and all digital I/Os of the radio transceiver are routed to the 2 × 20-pin expansion connector to interface to a power supply and a microcontroller.

Board-specific information such as board identifier, MAC address and production calibration values are stored in an ID EEPROM. The SPI bus of the EEPROM is shared with the radio transceiver interface.

AT02876: Atmel REB212BSMA Hardware User Manual [APPLICATION NOTE]

Atme l-42097B-WIRELESS-AT02876-REB212BSMA-Hardware-User-Manual_ApplicationNote_062014

REB212BSMA

AT86RF212B

RFP

RFN

RSTN

EXPAND1

XTAL2

XTAL1

XTAL

DIG1

CLKM

Protectio

EEPROM

SPI

IRQ

SLPTR

DIG4

DIG3

DIG2

TP6

TP7

Balun

JP1

GND

DEVDD

TP5

Figure 4-1. REB212BSMA Block Diagram

4.1 Interface Connector

The REB212BSMA is equipped with a 2 × 20-pin, 100mil, expansion connector, X1. The pin assignment enables a direct interface to the REB-CBB [2]. Further, the interface connects to the Atmel STK500/501 microcontroller development platform to enable support for various Atmel 8-bit AVR

The REB212BSMA is preconfigured to interface to an STK501 with an Atmel ATmega1281 or a REB-CBB with an Atmel ATxmega 256A3 respectively.

To operate the REB212BSMA with an Atmel ATmega644 on STK500, the 0Ω resistors R10 through R18 must be removed and re-installed on the board manually as resistors R20 through R28 (see Appendix A).

Other microcontroller development platforms need to be interfaced using a special adapter board.

4.1.1 Atmel ATmega1281 Configuration

Table 4-1 lists the pin assignment of the ATmega1281 configuration (shipping default).

Table 4-1. Default Expansion Connector Mapping (ATmega1281 Configuration)

Pin# Function Pin# Function

1 GND 2 GND

3 n.c. 4 n.c.

5 n.c. 6 n.c.

7 n.c. 8 n.c.

9 n.c. 10 n.c.

microcontrollers.

11 n.c. 12 n.c.

AT02876: Atmel REB212BSMA Hardware User Manual [APPLICATION NOTE]

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(1)

Pin# Function Pin# Function

13 n.c. 14 n.c.

15 n.c. 16 n.c.

17 n.c., optionally XT1 (MCLK)

19 VCC 20 VCC

21 GND 22 GND

23 PB7 (open) 24 PB6 (open)

25 PB5 (RSTN) 26 PB4 (SLPTR)

27 PB3 (MISO) 28 PB2 (MOSI)

29 PB1 (SCLK) 30 PB0 (SEL)

31 PD7 (TP1) 32 PD6 (MCLK)

33 PD5 (TP2) 34 PD4 (DIG2)

35 PD3 (TP3) 36 PD2 (open)

37 PD1 (TP4) 38 PD0 (IRQ)

39 GND 40 EE#WP (write protect EEPROM)

Note: 1. Possible by retrofitting a 0R assembly.

4.1.2 Atmel ATmega644 Configuration

Table 4-2 lists the pin assignment of the ATmega644 configuration. It is enabled by re-assembling R10 through

R23 to their alternate locations.

18 n.c.

Table 4-2. Expansion Connector Mapping when Assembled for ATmega644

Pin# Function Pin# Function

1 GND 2 GND

3 n.c. 4 n.c.

5 n.c. 6 n.c.

7 n.c. 8 n.c.

9 n.c. 10 n.c.

11 n.c. 12 n.c.

13 n.c. 14 n.c.

15 n.c. 16 n.c.

17 n.c., optionally XT1 (MCLK)

18 n.c.

19 VCC 20 VCC

21 GND 22 GND

23 PB7 (SCLK) 24 PB6 (MISO)

25 PB5 (MOSI) 26 PB4 (SEL)

27 PB3 (open) 28 PB2 (RSTN)

29 PB1 (MCLK) 30 PB0 (open)

AT02876: Atmel REB212BSMA Hardware User Manual [APPLICATION NOTE]

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> 1

PB 5 ( RSTN

)

SPI

PB 1 .. 3 (

SPI )

Transceiver

AT86RF212B

ID EEPROM

PB 0 ( SEL )

RSTN

SELN

#CS

Pin# Function Pin# Function

31 PD7 (SLPTR) 32 PD6 (DIG2)

33 PD5 (TP2) 34 PD4 (open)

35 PD3 (TP3) 36 PD2 (IRQ)

37 PD1 (TP4) 38 PD0 (open)

39 GND 40 EE#WP (write protect EEPROM)

Note: 1. Possible by retrofitting a 0R assembly.

4.2 ID EEPROM

To identify the board type by software, an identification (ID) EEPROM (U5) is populated. Information about the board, the node MAC address and production calibration values are stored here. A serial EEPROM AT25010B

[3] with 128 × 8-bit organization and SPI bus is used because of its small package and low-voltage and

low-power operation.

The SPI bus is shared between the EEPROM and the transceiver. The select signal for each SPI slave (EEPROM, radio transceiver) is decoded with the reset line of the transceiver, RSTN. Therefore, the EEPROM is addressed when the radio transceiver is held in reset (RSTN = 0; see Figure 4-2).

Figure 4-2. EEPROM Access Decoding Logic (Atmel ATmega1281 Configuration)

The EEPROM data is written during board production testing. A unique serial number, the MAC address, and calibration values are stored. These can be used to optimize system performance. Table 4-3 shows a detailed description of the EEPROM data structure.

Table 4-3. ID EEPROM Mapping

Address Name Type Description

0x00 MAC address uint64 MAC address for the 802.15.4 node, little endian byte order

0x08 Serial number uint64 Board serial number, little endian byte order

0x10 Board family uint8 Internal board family identifier

0x11 Revision uint8[3] Board revision number ##.##.##

AT02876: Atmel REB212BSMA Hardware User Manual [APPLICATION NOTE]

Atme l-42097B-WIRELESS-AT02876-REB212BSMA-Hardware-User-Manual_ApplicationNote_062014

Address Name Type Description

0x14 Feature uint8 Board features, coded into seven bits

7 Reserved

6 Reserved

5 External LNA

4 External PA

3 Reserved

2 Diversity

1 Antenna

0 SMA connector

0x15 Cal OSC 16MHz uint8 XTAL calibration value, register XTAL_TRIM

0x16 Cal RC 3.6V uint8

0x17 Cal RC 2.0V uint8

0x18 Antenna gain int8

0x20 Board name char[30] Textual board description

0x3E CRC uint16

Atmel ATmega1281 internal RC oscillator calibration value @ 3.6V, register OSCCAL

Atmel ATmega1281 internal RC oscillator calibration value @ 2.0V, register OSCCAL

Antenna gain [resolution 1/10dBi]. For example, 15 will indicate a gain of 1.5dBi.

The values 00h and FFh are per definition invalid. Zero or

-0.1dBi has to be indicated as 01h or FEh

16-bit CRC checksum, standard ITU-T generator polynomial G16(x) = x16 + x12 + x5 + 1

Example: EEPROM dump.

0000 D0 63 17 FF FF 25 04 00 DC 25 00 00 4E 00 00 00 .c...%...%..N...

0010 00 05 00 03 02 00 86 86 00 FF FF FF FF FF FF FF ................

0020 52 61 64 69 6F 45 78 74 65 6E 64 65 72 32 31 32 RadioExtender212

0030 42 53 4D 41 00 00 00 00 00 00 00 00 00 00 2B D5 BSMA..........+.

0040 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF ................

0050 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF ................

0060 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF ................

0070 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF ................

4.3 Supply Current Sensing

A jumper, JP1, is placed in the supply voltage trace to offer an easy way for current sensing. The current consumption of all circuitry connected to the supply domains DEVDD/EVDD such as AT86RF212B and AT25010B can be measured by connecting an ampere meter instead of the jumper cap JP1, see Figure 4-3.

The power supply pins of the radio transceiver are protected against overvoltage and reverse polarity at the X1 connector pins (net CVTG, net DGND) using a Zener diode, D1, and a thermal fuse, F1, (see Appendix A). This is required because the Atmel STK500 will provide 5V as default voltage, and the board can also be mounted with reverse polarity.

Depending on the actual supply voltage, the diode D1 can consume several milliamperes. This has to be considered when the current consumption of the whole system is measured. In such a case, D1 should be removed from the board.

To achieve the best RF performance, the analog (EVDD) and digital (DEVDD) supply are separated from each other by a CLC PI-filter.

AT02876: Atmel REB212BSMA Hardware User Manual [APPLICATION NOTE]

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+ 14 hidden pages

Microchip Technology A091619 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Introduction

Features

1 Introduction

2 Disclaimer

3 Overview

4 Functional Description

4.1 Interface Connector

4.1.1 Atmel ATmega1281 Configuration

4.1.2 Atmel ATmega644 Configuration

4.2 ID EEPROM

4.3 Supply Current Sensing