Legacy UART-RF-Protocol

Overview

The Demo-Software implemets an UART-to-Radio protocol. For an easy use the pakets to the uart have to be send as hex-values as ASCII, meaning 0x00 ia send as "00". Only '0'-'9' and 'A'-'F' are accepted letters. Additionaly there is an 'Magic Word' - the letter 'S'. The 'S' is used as sync byte to start a packet.

UART packets to radio

The packets to the UART alway have a fixed sceme:

packets to uart of the radio

• first letter is the 'S'
• followed by 2 bytes length of the packet (N + 1(type) +16(address))
• followed by 16 bytes IPv6 address of the destination, the IPv6 address ::1 is reserved for the Local Host. Packets to the ocal host are not sent over radio, but they are commands to the module.
• followed by 1 type-byte, that determines the type of the packet. When a module receives the packet, it decides with the type how to handle the packet data. There are several packet types pre-defined - as seen below.
• followed by N data bytes.

Example 1 - Packet to the UART:

S0015FF0200000000000000000000000000010012345678

This commad sends an Broadcast data packet with 4 bytes of data =0x12345678.

• the length is 16Bytes(address) + 1Byte(type) + 4Bytes(data) = 21Bytes = 0x15
• the address FF020000000000000000000000000001 is the IPv6 broadcast address
• type 0x00 means that the packet is a data packet, see the pre-defined packet types below
• the data are 0x12 0x34 0x56 0x78

UART packets from radio

When the radio sends packets via UART, theese packets also have a fixed sceme:

packets from uart of the radio

• first letter is the 'S'
• followed by 2 bytes length of the packet (N + 1(type) +16(address))
• followed by 16 bytes IPv6 address of the destination, the IPv6 address ::1 is reserved for the Local Host. Packets to the ocal host are not sent over radio, but they are commands to the module.
• followed by 1 type-byte, that determines the type of the packet. When a module receives the packet, it decides with the type how to handle the packet data. There are several packet types pre-defined - as seen below
• followed by N data bytes
• followed by one byte RSSI (Radio Signal Strength Indicator) as 8-bit signed integer

NOTE: the RSSI byte is not counted to the length of the packet!

• every packet from the radio closes with an <CR><LF> (hex values 0x13 0x10). So te user can just read one line from the uart and gets the hole packet.

Example 2 - Packet from the UART:

S0014FE80000000000000001FE001000000030600C901C9

The Radio received a packet from node FE80000000000000001FE00100000003 with type=0x06 and data 0x00C901. The RSSI of the received packet was 0xC9= -55dBm

• the length is 16bytes(source address) + 1byte(type) + 3Bytes(data) = 20Bytes = 0x14 (the RSSI is not counted to the length of the packet)
• the address FE80000000000000001FE00100000003 is the IPv6 address of the sender
• type 0x00 means that the packet is a data packet, see the pre-defined packet types below
• the data are 0x12 0x34 0x56 0x78

Implemented Commands / Packet Types

The UART-RF-protocol pre-defines several types of packets (type byte in the packets). Pre-defined packet types are:

typedef enum {
 PACKET_TYPE_DATA                            = 0x00,
 PACKET_TYPE_BIND                            = 0x01,
 PACKET_TYPE_BINDACK                         = 0x02,
 PACKET_TYPE_UNBIND                          = 0x03,
 PACKET_TYPE_SETUP                           = 0x04,
 PACKET_TYPE_SETUP_ACK                       = 0x0C,
 PACKET_TYPE_DISCOVER_NETWORK                = 0x05,
 PACKET_TYPE_DISCOVER_NETWORK_REPLY          = 0x06,
 //board specific commands for ADB2001
 PACKET_TYPE_LED_DATA                        = 0x07,
 PACKET_TYPE_BTN_DATA                        = 0x08,
 //board specific commands for ICradioPlug
 PACKET_TYPE_PLUG_GET                        = 0xF0,
} PACKET_TYPE_t;

Setup Command

   not yet implemented

Setup Acknowledge Packet

   not yet implemented

Board specific commads

Get Plug Data Packet

S00110000000000000000000000000000000105
S - sync letter
0011 - length = 0x11 = 17 bytes
00000000000000000000000000000001 - address = ::1 (IPv6 Local Host)
05 - type is 0x05 = discover-network command

This is the commad 0x05 to the Local Host. It is the command to discover the network - see below for available commands. The module executes the stack-command for scanning the network.

void rf_CallbackDiscover( unsigned char hopCount, char rssi, unsigned char  addrCount, ZWIR_IPv6Address_t*  address ) {
 uint8_t data[2];
 data[0] = hopCount;
 data[1] = rssi;
 packetHandler(SOURCE_RF, address, PACKET_TYPE_DISCOVER_NETWORK_REPLY, data, 2);
}

When nodes are discovered, a callback routine is called. The packet handler then sends this packet via uart. The module sends to the uart a packet with PACKET_TYPE_DISCOVER_NETWORK_REPLY with the received address, the hop-count and the RSSI of the node that was discovered.

 S0013FE0800000000000000000000000012340601DF

This reply means that the node FE080000000000000000000000001234 is 1 hopcounts away and is received with -33dBm signal strength.

Some special commands are also implemented and have to be sent via UART to the LOCAL-HOST (::1)

• scanning the network

 S00110000000000000000000000000000000105

• getting the module's IPv6 address

 S00110000000000000000000000000000000109

• setting the module's LED's

 S001300000000000000000000000000000001070100  (set LED1=on, LED2=off)
 S001300000000000000000000000000000001070001  (set LED1=off, LED2=on)