BRA - Bladox Radio Architecture

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Detailed Description

BRA API is available only on devices with radio interface - Turbo BRA. It is possible to upload application to any Turbo device but it will use null wrapper.

BRA is a radio protocol based on 802.15.4 standard. It follows the same goals as ZigBee(tm) but it is simpler and truly open. It can utilize both non-sleeping (always ready) and sleeping (idle) devices/nodes.

BRA is:

• multiapplication - device (node) can be Point Of Sales, Router and Messaging gateway at the same time
• message oriented - device control, not streaming
• low power consumption - both for non-sleeping and sleeping devices
• open - access to specs and both commercial and non-commercial use
• simple to develop

MAC Layer Frame Format

BRA Layer Frame Format

Defines

• #define DEF_BRA_MAC_LEN
• #define DEF_BRA_VERSION
• #define T_BRA_VERSION
• #define T_BRA_DEST
• #define T_BRA_SRC
• #define T_BRA_TAG
• #define T_BRA_DATA
• #define DEF_BRA_MIN_FREQ
• #define DEF_BRA_MAX_FREQ

Functions

• void bra_mac_reset ()
• void bra_mac_set (u8 addr[DEF_BRA_MAC_LEN])
• void bra_mac_get (u8 addr[DEF_BRA_MAC_LEN])
• u8 * bra_make_head (u8 *buf, u8 *dest_addr, u8 *tag, u8 release)
• u8 * bra_seek_head (u8 *buf, u8 tag)
• b8 bra_txrx (u8 *buf, u8 len, u8 *bra_app_tag, u8 nr_tx, u8 nr_rx, u8 after_tx_ms)
• u16 bra_lqi ()
• u8 bra_set_freq (u16 freq)
• u8 bra_set_802_15_4_channel (u8 channel)
• void bra_set_tx_power (u8 pa)
• u16 bra_freq ()
• u8 bra_tx_power ()
• u16 bra_cc2420_read (u16 addr)
• u16 bra_cc2420_write (u16 addr, u16 val)

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Define Documentation

#define DEF_BRA_MAC_LEN

BRA MAC address length. 4 bytes address format A.B.C.D is used. Every device has unique address burned in - can be modified by application. 255.255.255.255 denotes everybody.

#define DEF_BRA_MAX_FREQ

Max radio frequency - 2483 MHz. See CC2420 Radio Datasheet.

#define DEF_BRA_MIN_FREQ

Min radio frequency - 2400 MHz. See CC2420 Radio Datasheet.

#define DEF_BRA_VERSION

BRA packet version.

#define T_BRA_DATA

Application data in BRA packet.

#define T_BRA_DEST

Destination address tag in BRA packet.

#define T_BRA_SRC

Source address tag in BRA packet.

#define T_BRA_TAG

Application tag in BRA packet.

#define T_BRA_VERSION

Version tag in BRA packet.

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Function Documentation

u16 bra_cc2420_read (  u16  addr  )

Low level read access to CC2420 radio chip registers, RAM and strobe commands. See CC2420 Radio Datasheet. Parameters: addr  if MSB is '1' (i.e. |0x8000) then RAM is used, if 0 then register. Registers 0x00..0x0e are strobe commands. Returns: value of register/memory Examples: braping.c.

u16 bra_cc2420_write (  u16  addr, u16  val )

Low level write access to CC2420 radio chip RAM and registers. Write to registers 0x00..0x0e is equivalent to read operation, i.e. strobe command. See CC2420 Radio Datasheet. Parameters: addr  if MSB is '1' (i.e. |0x8000) RAM is used, registers otherwise val  value, for RAM only low byte is used Returns: result of the operation Examples: braping.c.

u16 bra_freq (   )

Returns current radio frequency. Returns: freq between DEF_BRA_MIN_FREQ and DEF_BRA_MAX_FREQ

u16 bra_lqi (   )

LQI - Link Quality Indicatior of the last packed received. Low byte is RSSI, hi byte is correlation as defined in CC2420 Radio Datasheet. Returns: value consists of RSSI|(CORR&0x7f) Examples: braping.c.

void bra_mac_get (  u8  addr[DEF_BRA_MAC_LEN]  )

Get device MAC address (possibly modified by bra_mac_set()). Examples: braping.c.

void bra_mac_reset (   )

Reset device MAC address previously modified with bra_mac_set() to factory default.

void bra_mac_set (  u8  addr[DEF_BRA_MAC_LEN]  )

Modify device MAC address.

u8* bra_make_head (  u8 *  buf, u8 *  dest_addr, u8 *  tag, u8  release )

Function to construct BRA packet. Parameters: buf  pointer on buffer used for packet construction dest_addr  NULL for everybody or specific destination address tag  application tag - used to select destination application release  indication if target device can go sleep. 1 means yes, target can go idle/sleep, 0 - further communication to follow Returns: pointer on buf after just constructed header. Examples: braled.c, and braping.c.

u8* bra_seek_head (  u8 *  buf, u8  tag )

Seek tag in BRA packet header. Parameters: buf  pointer on buffer containing BRA packet tag  what to seek: T_BRA_VERSION, T_BRA_DEST, T_BRA_SRC, T_BRA_TAG, T_BRA_DATA Returns: pointer on sought data in BRA packet Examples: braping.c.

u8 bra_set_802_15_4_channel (  u8  channel  )

Set radio frequency channel, can be between 11 and 26. Default is 26. Parameters: channel  11-26 as defined by ieee802.15.4 Returns: NO_ERROR, ERR_BRA_WRONG_CHANNEL Examples: braping.c.

u8 bra_set_freq (  u16  freq  )

Set radio frequency, can be between DEF_BRA_MIN_FREQ and DEF_BRA_MAX_FREQ. Default is 2480MHz (channel 26). Parameters: freq  frequency in MHz Returns: NO_ERROR, ERR_BRA_WRONG_FREQ Examples: braping.c.

void bra_set_tx_power (  u8  pa  )

Set radio Tx (transmit) power. See CC2420 Radio Datasheet. Parameters: pa  output power: 0-31 Examples: braping.c.

u8 bra_tx_power (   )

Returns current Tx power. Returns: pa 0..31, see CC2420 Radio Datasheet

b8 bra_txrx (  u8 *  buf, u8  len, u8 *  bra_app_tag, u8  nr_tx, u8  nr_rx, u8  after_tx_ms )

BRA Tx and Rx function - this is the main call for radio communication. Tx/Rx loop to communicate that can be used to communicate with both idle (sleeping) and ready (non-sleeping) devices. The loop looks following: while(nr_tx--) { tx(); tmp_nr_rx=nr_rx; while(tmp_nr_rx--) { delay_ms(after_tx_ms); rx(); if something received: check destination addr me or everybody check application tag } } Parameters: buf  pointer on buffer with BRA packet len  length of packet to send bra_app_tag  required BRA application tag to be received, can be NULL nr_tx  number of Tx nr_rx  number of Rx attempts after Tx after_tx_ms  delay between Tx/Rx (and following Rx's), in milisec Returns: 0 - nothing received, >0 length of received packet, <0 error Examples: braled.c, and braping.c.