SWRU437B September   2015  – June 2020 WL1801MOD , WL1805MOD , WL1807MOD , WL1831MOD , WL1835MOD , WL1837MOD

 

  1.   WiLink Module Hardware Integration Guide
    1.     Trademarks
    2. 1  Module Variant Table
      1. 1.1 WiLink WLAN Antenna Configuration
        1. 1.1.1 Single-Input Single-Output (SISO)
        2. 1.1.2 Multiple-Input Multiple-Output (MIMO)/Maximum Ratio Combining (MRC)
    3. 2  Critical Connections
    4. 3  Power Supply
      1. 3.1 Power Up/Shutdown Sequence
        1. 3.1.1 Power Up
        2. 3.1.2 Shutdown
      2. 3.2 Power Sequencing
    5. 4  Clocks
      1. 4.1 Slow Clock
      2. 4.2 Fast Clock
    6. 5  Current Consumption
      1. 5.1 Performance Parameters - Typical
    7. 6  Antenna
    8. 7  Ground Connections
    9. 8  Layout
    10. 9  Hardware Troubleshoot
      1. 9.1 System Requirements
      2. 9.2 Power Rails
      3. 9.3 Critcal Supplies
      4. 9.4 Sense on Reset
      5. 9.5 WLAN
        1. 9.5.1 WLAN Host Interface (SDIO)
        2. 9.5.2 WLAN IRQ Operation (SDIO Out-of-Band Interrupt)
      6. 9.6 Bluetooth and Bluetooth Low Energy
        1. 9.6.1 Bluetooth UART HCI Interface
        2. 9.6.2 Bluetooth PCM
      7. 9.7 Reserved Pins
      8. 9.8 Debug
    11. 10 WiFi_Zigbee Coex
    12. 11 References
  2.   Revision History

9.6.1 Bluetooth UART HCI Interface

  • The Bluetooth subsystem is controlled via an HCI 4-wire UART interface (H4).
  • Verify that the HCI interface is connected as shown in Figure 8. Note that a TX pin always routes to a RX pin, and a RTS pin always routes to a CTS pin.
    • bt_image.gifFigure 8. HOST HCI UART Interface

    Table 8. HCI UART Interface Lines

    Pin Number Name Type Description
    41 BT_EN I Bluetooth Enable
    50 BT_HCI_RTS O Bluetooth HCI UART request to send output
    51 BT_HCI_CTS I Bluetooth HCI UART clear to send input
    52 BT_HCI_TX O Bluetooth HCI UART transmit output
    53 BT_HCI_RX I Bluetooth HCI UART receive input
  • FUNC1_BT should be NC.
  • FUNC2_BT should be NC.

    • NOTE

    In the AM335x integration reference, the RTS and CTS lines are crossed, as shown. For some of the other processors, the RTS/CTS lines must be connected directly.
  • In case of host processor I/O is at 3.3 V, use a standard 245 level shifter and not a direction sensing one. For more information, see Level Shifting WL18xx I/Os (SWRA448).
  • Once Bluetooth EN is asserted to high the Bluetooth FW stored in ROM start to execute, during this time the RTS is driven high to prevent HCI transaction and not to interfere with device boot, once the FW finish the boot process RTS line goes low after approximately 100 mS.

    • If logger is configured at this point, WiLink should print boot up message.

    boot_up_seq_complete.jpgFigure 9. Bootup Sequence Complete
  • Connect HCI Tester and Set Baud Rate - 115200, Data Bits - 8, Stop bits -1, Parity - none, Flow Control - HW. On this port, send basic HCI commands (BD Address) to verify connectivity.
  • In case UART lines are not operating, make sure that the CTS line is set to 0 on the PC side - the signal on the WiLink Rx input line that comes from the PC (on the port Probe).

    • For every packet on Rx, there should be a response on the Tx line from WL18xx.