BM71 GAP Peripheral Demo (Making Connections)

Last modified by Microchip on 2023/11/09 09:03
Contents

Objective

This lab exercise will have you configure, then explore, Generic Access Profile (GAP) discovery and connection procedures on a BM71 configured as a GAP Peripheral, using a BM-71 PICtail™ board.

You will:

  • Configure key static module configuration settings using the User Interface (UI) Configuration Tool (Device Name, Pinout, Operation mode, Default ADV & SCAN_RSP packet payload data and interval, LED0, etc…)
  • Dynamically trigger GAP Discovery modes and procedures via BM71 OP codes using the Manual Pattern Test Tool
  • Interact with the board using a smartphone app

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Reference Materials

Hardware Tools

  • BM71 PICtail
  • Android Smartphone (Lab tested with BLU Advance 5.0).
    • OS version 4.4 or higher
    • BT 4.0 or higher hardware
  • Apple Smartphone
    • OS version 5 or later
    • BT 4.0 or higher hardware

This lab uses a BM71 PICtail with version 1.06 of the firmware. If you don't have v1.06 (or, are unsure which version you do have), go to the "BM71 Firmware Upgrade" page to update your BM71 module.

Software Tools

Be sure to install the MCP2200 USB drivers before starting. Also, download and extract the UI Configuration Tool as well as the Manual Pattern Test Tool to your PC using the links above.

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Connection Diagram

Connection Diagram

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Manual Pattern Flow Chart

For this example, the BM71 is configured to operate in Manual Pattern mode (i.e., a Generic Bluetooth® Low Energy (BLE) Link Controller). The following flow chart depicts the operation:

Manual Pattern Flow Chart

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Procedure

Peripheral Configuration

Place the Module in Test Mode

After connecting the PICtail to your PC using the supplied USB cable, place the module in Test mode by setting SW7 in the ON position, then press SW5 (Reset) to reset the module. Also, ensure the jumpers are all set as shown:

PICtail connected to PC using the supplied USB cable

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With Jumper JP8 shorted, LED0 will be lit (BLUE) indicating the module is in Test mode, as shown above.

Launch the UI Configuration Tool

Open the BLEDK3 UI Configuration Tool and load the default BM71 configuration file: IS1871SF_102_BLEDK3_UI v100.132(BM71) default.txt

load the default BM71 configuration file: IS1871SF_102_BLEDK3_UI v100.132(BM71) default.txt

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"Default" BM71 configuration files are located in the root folder where the UI Config Tool is installed.

Select Edit and ensure that the BLEDK radio button is checked and that BM71 is the device selected under the Main Feature window. Then press OK.

Select Edit button. BLEDK radio button is checked and that BM71 is the device selected under the Main Feature window. Press OK.

System Setup Tab

Change Device Name

In the Device Information pane, set the Name Fragment to lab2p-XXXX where XXXX is the last four digits of the BM71 MAC address. This identifier will become the GAP Service Device Name characteristic, as well as the Local Name identifier during advertising.

Set the Name Fragment in the Device Information pane

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This lab exercise was developed for a classroom environment having many radios. Appending the last four digits of the MAC address to the Device Name aids in identifying a specific board during the general discovery process.

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The device name should be unique. Also, since the advertising packet is pretty small (31-byte max. payload), we suggest you limit the name ID to fewer than eight characters (i.e., for the 10-character device name shown, if you try to add a 16-byte private service to the ADV payload, you will get an error message).

Disable UART_RX_IND

Scroll down to the Uart Setting pane, then select Disable from the UART RX_IND pull-down as shown.

Disable UART_RX_IND in the UART Setting pane

When enabled, this feature places the module into a Lower Power Operating mode, shutting off its UART RX operation. The host MCU needs to drive this pin low for at least 3 ms before sending the next packet to the module, as shown.

Host MCU Wakeup Timing Diagram

Configure Manual Pattern (BLE GATT) Operation Mode

In the Operation Mode Setting pane, select Manual Pattern for Operation Pattern as shown.

Operation Mode Setting pane, select Manual Pattern

Click OK on the pop-up dialog box that follows.

Click OK on the pop-up dialog box

Click Next to proceed to the next tab.

System Setup2 Tab

General Purpose Input/Output (GPIO) Configuration

In the GPIO Configuration pane, ensure the GPIO pin radio button settings are left at default settings as shown below.

GPIO Configuration pane

Click Next to proceed to the next tab.

LE Mode Setup Tab

ADV Packet Interval

In the LE Advertising Setting pane, set the ADV packet interval, referred to here as LE Fast Advertising Interval, to 100 ms by writing "0x00A0" in the field as shown below.

LE Advertising Setting pane, set the ADV packet interval

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LE Fast Advertising Timeout and LE Reduced Power Interval/Timeout parameters are only used for Auto-Pattern mode operation.

Leave the remaining parameters as-is.

ADV Packet Payload

In the Advertising Data Setting pane, ensure that Complete Device Name and Flag are checked and included in the payload. (The GAP Device Name characteristic will automatically be included in the ADV packet as the Local Name.)

In the Advertising Data Setting pane, ensure that Complete Device Name and Flag are checked

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This tab sets the default (static) ADV_IND type advertising packet payload, which is issued when the BM71 is operating in GAP General Discoverable mode. ADV types and parameters may be changed dynamically via op-code 0x13 (Set_Advertising_Parameter).

SCAN_RSP Packet Payload

In the Scan Response Data Setting pane, ensure that Tx Power is enabled for the payload.

Scan Response Data Setting pane, ensure that Tx Power is enabled

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A SCAN_RSP packet is returned to a Scanner that has issued a SCAN_REQ packet. These packets provide additional information to a Scanner/Central device.

The remainder of the settings are left at their defaults.

Write Settings

Press Finish.

Press Finish.

To program these settings into the BM71 module, click on Write, select the COM port you are using, and press Write again.

Select Write, select the COM port you are using and press Write again

On the window that pops up, click Yes and lastly, OK as shown above.

Close the UI Configuration Tool.

GAP Discovery and Connection

Discovery means:

  • Put the Peripheral in General Discoverable mode (start Advertising).
  • Trigger the Central to initiate the General Discovery Procedure (Scanning).

Connection means:

  • Central runs a general Connection Establishment Procedure (scan/select a peripheral based on certain criteria, then initiate a direct connection establishment procedure).
Place the Module in Application Mode

Move dip-switch SW7 to the OFF position (1) and reset the module by pressing SW5 (button immediately above dip-switch).

Board View: Move dip-switch SW7 to the OFF position and reset the module by pressing SW5

Launch the Manual Pattern Test Tool

Open the Manual Pattern Test Tool, and connect to the COM port associated with the board.

Manual Pattern Test Tool: Connect to the COM port

Command and Response

Verify the connection by sending a Read Local Information packet. Select 0x01: Read Local Information for Opcode in the Common tab.

Select 0x01: Read Local Information for Opcode in the Common tab

If the COM port connection was successful, you will see results similar to the following Log View and Local Information panes:

Log View and Local Information panes

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Log View does not display packet delimiter (0xAA) or checksum values on outgoing or incoming packets.

Command Packet Format

Analysis of the “Read Local Information” (0x01) Command Packet

Event Packet Format

Analysis of the “Read Local Information” (0x01) Event Packet

Mode of Operation

Verify the BM71 state/mode of operation by sending a Read BLEDK3 Status packet. Select 0x03: Read BLEDK3 Status for Opcode in the Common tab.

Select 0x03: Read BLEDK3 Status for Opcode in the Common tab

The module should be on Idle mode.

Configure Status shows Idle Mode

 

Advertising Overview (BM71)

Set Advertising Data

On BM71, the ADV interval, as well as ADV_IND and SCAN_RSP payload data can be set statically (using the UI Configuration Tool) and dynamically (via command op-codes/packets).

Since we’ve set an appropriate ADV_IND Interval, as well as ADV_IND and SCAN_RSP payload data using the UI Configuration Tool (steps 7 thru 9 above), we will not need to update them dynamically via the Manual Pattern evaluation tool below.

If you need to update ADV and SCAN_RSP payload data dynamically, select the ADV / SR Data tab and set advertising and scan response data payload. Then, pressing Update will issue GAP Command Opcode 0x11 (Write_Adv_Data) to update the payload data sent during Advertising (Standby) mode:

ADV / SR Data tab

If you need to update ADV Interval dynamically, GAP op-code 0x13 (Set_Adv_Parameter) may be used to dynamically alter the ADV interval:

GAP Tab in Manual Pattern evaluation tool

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On a BM71 Reset, the ADV interval, as well as ADV_IND and SCAN_RSP payload data will revert to those settings made in the UI Configuration Tool and saved to non-volatile configuration memory. Any dynamic changes (made via command op-codes/packets) will be lost.

Put the BM71 Peripheral in General Discoverable Mode

Begin Advertising

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All GAP operations are controlled via the GAP tab

In the GAP tab, select 0x1C: (Set Adv Enable) for Opcode. Select 0x01: (Enter Standby Mode) for Standby mode. Finally, press Send as shown:

GAP Tab in Manual Pattern evaluation tool

You should see the following indicators of success:

BT Status will show "0x03: Standby Mode"

BT Status showz "0x03: Standby Mode"

Blue LED (P2_0/LED) will blink once every three seconds (default setting - configurable via UI Config Tool):

Blue LED blinks once every three seconds

You should also see the peripheral’s Local Name displayed in the Smart Discover App, along with RSSI and ADV Interval (Android):

Local Name displayed in the Smart Discover App

Connect to the BM71 Peripheral Using SmartDiscover App

In the scan list, select the BM71 device you wish to connect to by tapping on it.

You will see the following indicators of success:

BT Status will show "0x0C: BLE Connected Mode" and LE Connection Information (provided by the Central) is also provided.

BT Status shows "0x0C: BLE Connected Mode"

Blue LED (P2_0/LED) will blink twice every 1.5 seconds (default setting -configurable via UI Config Tool):

Blue LED blinks twice every 1.5 seconds

In SmartDiscover, the default services will have been enumerated, and the ADV and SCAN_RSP data displayed for the device:

ADV and SCAN_RSP data displayed

Disconnect from the BM71 Peripheral Using SmartDiscover App

In the SmartDiscover app, disconnect from the device by tapping DISCONNECT.

You should see the following indicators of success:

BT Status will show "0x09 Idle Mode":

BT Status shows "0x09 Idle Mode":

Blue LED (P2_0/LED) will stop blinking:

Blue LED stops blinking:

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Conclusions

A GAP Peripheral device needs to be set up:

  • ADV payload data
  • SCAN_RSP payload data
  • Advertising interval
  • BM71 parameters may be modified statically or dynamically:
    • Statically: Using the UI Configuration Tool, or via Direct-write to configuration non-volatile memory.
    • Dynamically: Via op-codes/packets send to the module

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