Research

MSP430

Useful reading

• MSP430 Programming Intro

SimpliciTI

Overview

For help setting up Code Composer to use SimpliciTI see [1]

• Low power - proprietary network protocol
• Low cost - uses < 8K FLASH, 1K RAM
• Flexible - simple star and/or p2p Example Topology
• Simple - uses very basic core API
• Versatile - many different boards supported
• Low power - supports sleeping devices

Network Devices

• Access Point
  • Star hub in the network (1/net)
  • always-on
  • store and fwd for sleeping devices
• Range Extender
  • always-on device
  • limited to 4/net
• End Device
  • poll for data
  • API sequence (eg)
    • Init (and Join)
    • Link (assumes listen)
    • Sample Temp
    • Send
  • Option to sleep

End Devices

• Two approaches to getting messages
  • Polls AP (Requires AP!)
  • Listens for activity then stays awake and looks for frames destined for it

Architecture

• Layers
  • MRFI ("Minimal RF Interface") 'Physical'
  • NWK 'Network'
  • Applications, customer and nwk
• Network Support
  • init
  • ping
  • link/linklisten
  • nwk mgmt
  • send/receive
  • I/O

Components/simpliciti/nwk_api.h

Supports initialization, linking (bi-directional by default), peer-to-peer messaging (SMPL_Send/Receive), configuration (SMPL_loctl)

smplStatus_t SMPL_Init(uint8_t (*)(linkID_t));
smplStatus_t SMPL_Link(linkID_t *);
smplStatus_t SMPL_LinkListen(linkID_t *);
smplStatus_t SMPL_Send(linkID_t lid, uint8_t *msg, uint8_t len);
smplStatus_t SMPL_SendOpt(linkID_t lid, uint8_t *msg, uint8_t len, txOpt_t);
smplStatus_t SMPL_Receive(linkID_t lid, uint8_t *msg, uint8_t *len);
smplStatus_t SMPL_Ioctl(ioctlObject_t, ioctlAction_t, void *);
#ifdef EXTENDED_API
smplStatus_t SMPL_Ping(linkID_t);
smplStatus_t SMPL_Unlink(linkID_t);
smplStatus_t SMPL_Commission(addr_t *, uint8_t, uint8_t, linkID_t *);

Addressing and Communication

• net address = hw addr (4 byte) + app port
  • statically assigned hw address
  • no address resolution mechanism
• byte 1: 0x00, 0xFF - reserved for broadcast
• Can communicate through RE/AP or to neighbours
• When debugging it is important to make sure the devices have addresses set :
  • Up to this point, no changes have been needed to any SimpliciTI source code or configuration files. The first device was built and programmed with “out-of-the-box” settings. In order to build another LinkTo device for this sample application, one change must be made to the smpl_config.dat file. Each SimpliciTI device must have a unique address – the address shown below is the one that was used for the first LinkTo device. Before building another device, change the value of THIS_DEVICE_ADDRESS – the first byte is suggested, like, from 0x78 to 0x87.

Broadcasting

• Can be done using the "Unconnected User Datagram" protocol
• Still uses links but it's a special reserved link that everyone can send/listen on

SMPL_Send(SMPL_LINKID_USER_UUD, ...)
SMPL_Receive(SMPL_LINKID_USER_UUD,...)

• Need to remember to switch the receiving node into RX mode, not done by default as uses lots of power!
  • An ioctl call can be used to enable/disable
  • Examples and troubleshooting

Additional Details (Potential Problems)

• minimal hw abstraction
• no driver support (UART, SPI, LCD, Timers)
• no heap utilization
• no runtime context storage
• simple thread, no tasks or scheduling
• nwk api is synchronous
• retries and acks must be managed by app
• "The SimpliciTI API should not be considered thread-safe or re-entrant"
• No routing mechanism is supported, only works by the addresses given to the devices

Development Tools

• Packet sniffer

Components/simpliciti/nwk.h

smplStatus_t  nwk_nwkInit(uint8_t (*)(linkID_t));
connInfo_t   *nwk_getNextConnection(void);
void          nwk_freeConnection(connInfo_t *);
uint8_t       nwk_getNextClientPort(void);
connInfo_t   *nwk_getConnInfo(linkID_t port);
connInfo_t   *nwk_isLinkDuplicate(uint8_t *, uint8_t);
uint8_t       nwk_findAddressMatch(mrfiPacket_t *);
smplStatus_t  nwk_checkConnInfo(connInfo_t *, uint8_t);
uint8_t       nwk_isConnectionValid(mrfiPacket_t *, linkID_t *);
uint8_t       nwk_allocateLocalRxPort(uint8_t, connInfo_t *);
uint8_t       nwk_isValidReply(mrfiPacket_t *, uint8_t, uint8_t, uint8_t);
connInfo_t   *nwk_findPeer(addr_t *, uint8_t);
smplStatus_t  nwk_NVObj(ioctlAction_t, ioctlNVObj_t *);
uint8_t       nwk_checkAppMsgTID(appPTid_t, appPTid_t);
void          nwk_getNumObjectFromMsg(void *, void *, uint8_t);
void          nwk_putNumObjectIntoMsg(void *, void *, uint8_t);
#ifdef ACCESS_POINT
sfInfo_t     *nwk_getSFInfoPtr(void);
#ifdef AP_IS_DATA_HUB
uint8_t       nwk_saveJoinedDevice(mrfiPacket_t *);
connInfo_t   *nwk_findAlreadyJoined(mrfiPacket_t *);