蓝牙一般应用状态机

1、Application Flow:· Write device class· Turn Security on· Allow SDP browsing· Initialize HID library l Message = CL_INIT_CFM(Initialize the connection library) Message = HID_INIT_CFM(Initialize the HID library)· Set app state to appDiscoverable.· Store the library handle

2、.status = successPanic and exit application.Cstatus = successPanic and exit application.YNYNYMessageLoop:· Initialize the app_handler· Initialize the PIO lines (1,2,3,4 as o/p and 6,7,8,9 as i/p)· Initialize the connection manager YABNYNSet appstate =appDiscoverableSet appstate =appDi

3、scovera-bleConnected· Set the trust level· Set appstate = appCableConnectedAuthenticateSuccess?· Store the connection instance.· Save the HID interrupt sinkYConnection success? Message = HID_CONNECT_CFM(Confirm connection)· Stop the pin-code entry· Set the auth status t

4、o trusted.Y· Stop the pin-code entry.· Set auth status to idleNAuthenticate = success ? Message =CL_SM_PIN_CODE_IND(Send pin-code response) ABAYBsYY Message = CL_SM_AUTHENTICATE_CFM(Authentication check)· Store host device address· Send the fixed pin-code response of 0000BxCGener

5、ate a new STROBE_MESSAGE after delay of 5 ms· Detect if any modifier (ALT, CTRL or SHIFT) has been pressed.· Prepare the HID input report.· Connect the interrupt stream· Send the HID report over the interrupt line· Disconnect the interrupt stream· Prepare a blank HID in

6、put report to notify the host end of data· Connect the interrupt stream· Send the blank HID input report· Disconnect the interrupt stream· Clear tmpYYStore the key_state. tmp = key_stateNNCheck if key is released(tmp > key_state) ?If a new key_state is generated i.e. a new key

7、 is pressed or a key is released· Strobe PIO line 3 and read contents of PIO line 9,8,7,6 in 0-3 bits of key_state.· Strobe PIO line 2 and read contents of PIO line 9,8,7,6 in 4-7 bits of key_state.· Strobe PIO line 1 and read contents of PIO line 9,8,7,6 in 8-11 bits of key_state.

8、83; Strobe PIO line 4 and read contents of PIO line 9,8,7,6 in 12-15 bits of key_state.YA Message = STROBE_MESSAGE(Generated every 5 ms to detect key state)Description: The above diagram shows the application flow. The application goes through four major stages:1. Library Initialization: The code fo

9、r this functionality is in the file main.c and hid_keyboard_sm.cOn powering the Bluetooth chip following two libraries are initialized:a. Connection library: The initialization is done in the main function of the application. Before initialization the PIO lines direction and debounce are set. Functi

10、on:· void ConnectionInitEx (  Task  theAppTask, const msg_filter *  msgFilter ) After initialization of the connection manager the message CL_INIT_CFM is sent to the application handler. On receiving the above message following actions are performed:i. Check if the connectio

11、n library initialization was successful, if yes proceed to following steps else panic and exit the application.ii. Write the class of the device as a (HID_MAJOR_DEVICE_CLASS | HID_MINOR_KEYBOARD).Function:· void ConnectionWriteClassOfDevice (  uint32  cod  ) iii. Turn the se

12、curity on.Functions:· void ConnectionSmSetSecurityMode (  Task  theAppTask, dm_security_mode  sec_mode, encryption_mode  enc_mode ) · void ConnectionSmRegisterIncomingService (  dm_protocol_id  protocol_id, uint32  channel, dm_security_level  se

13、curity_level ) iv. Allow SDP record browsing.Function:· void ConnectionSmSetSdpSecurityIn (  bool  enable  ) v. Initialize the HID library.Function:· void HidInit (  Task  theAppTask, const hid_config *  config ) b. HID library: After initializa

14、tion of the HID library the message HID_INIT_CFM is sent to the application handler. On receiving above message the following actions are performed:i. Check if the HID library initialization was successful if yes proceed to following steps else panic and exit the application.ii. Record the hid libra

15、ry handle.iii. Initialize the application variables.iv. Set the application state to discoverable i.e. app_state = appDiscoverableNow the chip is in discoverable mode and waits for incoming connection. 2. HID Connection: The code for this functionality is in the file main.c and hid_keyboard_auth.c.

16、Any host can now discover the chip and try to pair with it. The default passkey used for connection is 0000. This is stored in the application therefore any host device needs to use the above mentioned passkey for pairing. a. On an attempt by the host device for connection the message CL_SM_PIN_CODE

17、_IND is sent to the application handler. In response the following actions are performed:i. The host address is stored.ii. Response is sent to the host with passkey as 0000.Function:· void ConnectionSmPinCodeResponse (  const bdaddr *  bd_addr, uint16  size_pin_code, const uint8

18、*  pin_code )  b. After the host verifies the connection a response is sent to the chip by the host. The message CL_SM_AUTHENTICATE_CFM is received by the application handler. The following actions are performed:i. If authentication by the host device was successful then goto step ii. else

19、 step iii. ii. Set the application state to cable connected i.e. app_state = appCabledConnected and authentication state to trusted i.e.auth_state = appAuthTrustediii. Set the application state to discoverable i.e. app_state = appDiscoverable and authentication state to idle i.e. auth_state = appAut

20、hIdleThe device once in appCableConnected is ready to send input data to the host. 3. Detection of Key-press: The code for this functionality is in the file main.c.The input matrix is connected to the PIO lines. The Bluecore chip has 12 PIO lines and the input matrix has 16 lines. Since the number o

21、f PIO lines are less multiplexing is done. The PIO lines 0, 1, 2 and 4 are output lines and 6, 7, 8 and 9 are input lines. Once the application moves into the cableConnected state an initial strobe message is generated in the application handler. Later on the strobe messages are generated every 5 ms

22、.On receiving the strobe message the following actions are performed: i. Sampling: The output lines are strobed in sequence of 2, 1, 0 and 4. On each strobe of output line the input lines 6, 7, 8 and 9 are sampled. The 4 bits are assembled and stored in the key state. The key state is of 2 bytes and

23、 the contents of it are as follows:· 0-3 bits: Sampled when output line 2 is strobed. o Bit 0 PIO line 9o Bit 1 PIO line 8o Bit 2 PIO line 7o Bit 3 PIO line 6· 4-7 bits: Sampled when output line 1 is strobed. o Bit 4 PIO line 9o Bit 5 PIO line 8o Bit 6 PIO line 7o Bit 7 PIO line 6· 8-

24、11 bits: Sampled when output line 0 is strobed. o Bit 8 PIO line 9o Bit 9 PIO line 8o Bit 10 PIO line 7o Bit 11 PIO line 6· 12-15 bits: Sampled when output line 3 is strobed. o Bit 12 PIO line 9o Bit 13 PIO line 8o Bit 14 PIO line 7o Bit 15 PIO line 6Once the new state is sampled it is compared

25、 with the previous state stored to check if a new key has been pressed or a pressed key has been released. If the new key state sampled is different than the previous state stored then set the previous state to new state and report the key press by calling the function void appHandleMyDataAux(appTas

26、kData *theApp, uint16 contents_pio).4. Reporting of Key-press: The code for this functionality is in the file hid_keyboard_aux.c. Once a new key state has been detected, it has to be determined whether a new key has been pressed or a pressed key has been released. As per the chording functionality o

27、n the twiddler a key-code is reported to the host only on key release. So initially a check is made for this by comparing the previous key state stored with the new key state reported. i. If the new key state is less than previous key state then a key has been released else a new key has been presse

28、d. If new key state is less than previous key state then goto step ii. else goto step vi.ii. Prepare the data for HID input report using the previous key state since it is the key state to be reported. The data for HID input report is of 9 bytes. The contents are described as follows:a. Byte 0: This

29、 byte is set to 0x01 for input report b. Byte 1: Reservedc. Byte 2: This byte is used to report the modifiers. The twiddler has following modifiers:· Control key: The byte is set to 0x01· Alt key: The byte is set to 0x04· Shift key: The byte is set to 0x02 If no modifier is pressed th

30、en the byte is set to 0x00. d. Byte 3-8: These six bytes are used to report the HID key-code of the key pressed. So in one input report six key presses can be sent. Based on the key state detected the HID key-codes to be reported are obtained using HID key-code mapping case structure. iii. The input

31、 report formed is sent over the HID interrupt line.Function:· void HidInterruptReport (  HID *  hid, hid_report_type  report_type, uint16  report_length, const uint8 *  data ) · bool StreamConnect (  Source  , Sink  ) · void StreamDisc

32、onnect (  Source  , Sink  ) iv. After reporting the data an empty report needs to be sent so that the host can detect end of input. So an empty report (all 9 bytes set to 0x00) is sent over HID interrupt line.· void HidInterruptReport (  HID *  hid, hid_report_type

33、  report_type, uint16  report_length, const uint8 *  data ) · bool StreamConnect (  Source  , Sink  ) · void StreamDisconnect (  Source  , Sink  ) v. Clear the previous key state.vi. Set the previous key state to new key state.Improvements:1. Most of the HID devices use the control line for reporting th