Vela IF820 Series - Bluetooth 5.4 Dual-Mode Modules

In addition to the code examples that are available in the AIROC™ Bluetooth® SDK, there are optional sets of packages that add extra features to the AIROC™ Bluetooth® SDK. These are typically more complex applications or require special licensing. The Pro CEs are not available on GitHub repositories.

The formal way Pro Examples are shared is by the customer creating an account in the Infineon Developer Community and by getting their registered Email ID and account username.

The customer needs to share their MFi License details with Infineon.

The Infineon marketing team will then upload the Pro Example in the community.

The Vela  IF820 DVK uses a RP2040 to provide UART com ports for the DVK.

You can check the version of RP2040 firmware using the following, which assumes you have Python and pyocd installed.

pyocd list -v -v -v

which should return the RP2040 firmware of all boards currently connected which should look something like this

PS C:\Python311> pyocd list -v -v -v

0000733 D Project directory: C:\Python311 [session]

0001190 D CMSIS-DAP v2 probe E6620CD64F488232: firmware version 1.3.0+1694472875, protocol version 2.1.1 [dap_access_cmsis_dap]

0001280 D CMSIS-DAP v2 probe E6625C05E767202F: firmware version 1.3.0+1694472875, protocol version 2.1.1 [dap_access_cmsis_dap]

0001358 D CMSIS-DAP v2 probe E6625C05E789602C: firmware version 1.3.0+1694472875, protocol version 2.1.1 [dap_access_cmsis_dap]

  #   Probe/Board                              Unique ID          Target

------------------------------------------------------------------------------

  0   Ezurio DVK Probe CMSIS-DAP   E6620CD64F488232   ✔︎ cortex_m

      Ezurio                       Module

  1   Ezurio DVK Probe CMSIS-DAP   E6625C05E767202F   n/a

  2   Ezurio DVK Probe CMSIS-DAP   E6625C05E789602C   n/a

PS C:\Python311>

If the IF820 flasher GUI or CLI utility does not detect the IF820 DVK it may be that the RP2040 used for providing serial/debug ports on the Vela IF820 may need updating. 

Please contact a Laird FAE via support@lairdconnect.com for more details

To use UWTerminalX with the Vela IF820 it is recommended to use the following settings

• Tick DTR
• Untick BREAK
• Untick Localecho
• Untick linemode
• baud rate 115200
• parity none
• stop bits 1
• data bits 8
• handshaking none
• Terminal select  CR
• use UART 1

On booting the Vela IF820, if all is good you should see the EZ-Serial boot message something like this, note the @E indicates an event, in this case boot.

@E,0074,BOOT,E=01040808,S=03010000,P=0104,H=23,C=00,A=E0984030FB5D,F=EZ-Serial-CYBT_243053_02 V1.4.8.8 Jun  9 2023 10:03:25

To confirm two way communications send/type the following followed by carriage return

/ping

To which the module should respond with somthing like the following, note the @R indicates a response, in this case to the /ping command. The /PING,0000 indicates the command was successful

@R,001D,/PING,0000,R=0000007F,F=F218

The Vela IF820 exposes to UARTS.

• UART 0 also known as the HCI UART
• UART 1the EZ-Serial UART (115200,8N1 no flow control)

On booting a Vela IF820 loaded with EZ-Serial Firmware a boot message will be sent on UART 1 and will look something like this

@E,0074,BOOT,E=01040808,S=03010000,P=0104,H=23,C=00,A=E77BCEF68661,F=EZ-Serial-CYBT_243053_02 V1.4.8.8 Jun  9 2023 10:03:25

Firmware updates should be performed on UART 0

Firmware and flashing tools can be downloaded from https://github.com/LairdCP/Vela_IF820_Firmware/releases

The Vela IF820 is preloaded with EZ-Serial firmware which can be used in one of two modes

• Text API
• Binary API

Text mode API provides human readable commands that can be sent to the module over the UART, typically from a microcontroller or from a PC terminal program during development.

Commands take the form of short code, for example

• /rbt          will reboot the module
• /bti          will start a Bluetooth classic inquiry
• /s             will start a scan for BLE adverts

The text mode API is particularly useful when first using EZ-Serial.

The binary mode API may be a better choice for production devices due to having a simpler parset/generator for the UART host. Binary mode uses a fixed packet structure for every transaction. Each packet is made up of the following

• 4 byte header
• optional payload
• checksum byte

For example a command to get the GAP device name might look like this

C0 00 04 10 6D

and the response might look like this

C0 15 04 10 00 00 12 45 5A 2D 53 65 72 69 61 6C 20 31 41 3A 32 31 3A 44 33 A0 

The first four bytes are the header (command), the 00 00 represents success, the 12 45 5A 2D 53 65 72 69 61 6C 20 31 41 3A 32 31 3A 44 33 is the  returned name and the final byte is the checksum.

Yes, the Vela IF820 does support flow control but it is not enabled by default.

The default UART settings are

• 115200 baud
• 8 data bits
• no parity
• 1 stop bit
• no flow control

The UART settings can be changed using the system_set_uart_parameters command (stu)

The UART settings can be read using the system_get_uart_parameters command (gtu)

If using MODUS Toolbox on the IF820 it can support Hands Free Profile (HFP) over the I2S/PCM interface. Infineon, in MODUS Toolbox, supports mSBC and CVSD audio CODECs in FW which is used in HFP.

SBC CODEC which is used as the compression algorithm for Advance Audio Distribution Profile (A2DP) could be done in FW as well but the I2S interface doesn’t support 44KHz/48KHz sample rates, thus, it can’t be used for A2DP.

There is no support for LE Audio.

By default, the Vela IF820 module is loaded with EZ-Serial firmware, which has Classic Bluetooth SPP data mode active by default.

The EZ-Serial firmware platform for Laird Vela IF820 series module supports Bluetooth Classic SPP service as a simple method to send and receive serial data over a Bluetooth connection. This operational mode is separated from the normal command mode where the API protocol may be used. When SPP data mode is active, any data received from an external host will be transmitted to the remote peer, and any data received from the remote peer will be sent out through the hardware serial interface to the external host.

To connect Vela IF820 via Bluetooth SPP profile using a computer (Windows) follow these steps:

1.    Click the Bluetooth icon on your Windows Taskbar or access the Bluetooth menu from Control Panel > All Control Panel Items > Devices and Printers. Select Add a device.

2.      Select device named “EZ-Serial XX:XX:XX_BT” and connect. Windows will install drivers for this device. You will find two ports associated with this device in Device Manager.

3.      Open a terminal application and connect to the COM port (typically the lower numbered COM port is the port to select).

Now you can transfer data between the terminal application in Windows and the terminal of the Laird Vela IF820 module.

There are two ways to disconnect from an SPP connection.

1. Using the CYSPP pin
2. Using the disconnect command in non-transparent mode

SPP can be controlled through the hardware GPIO on the EZ-Serial firmware platform for Laird Vela IF820 series module. Cyspp pin, which is also used for CYSPP, can be used to control the SPP connection state:

• By default, CYSPP pin is set in HIGH state.

• Once SPP connection is active, CYSPP pin will be set to LOW state.

• If CYSPP pin is set to HIGH by an ex ternal MCU while a SPP connection is active, the SPP connection will be terminated.

Note there is a jumper on the IF820 DVK that may be pulling CYSPP high which needs to be removed before using this method of disconnection.

In non-transparent mode, though SPP is connected, user still can use command mode. Data receive from SPP connection will arrive with event “.SPPD”. See the command protocol_set_parse_mode (SPPM, ID=1/1) to use non-transparent mode. See bt_disconnect (/BTDIS, ID=14/6)

Each variant of the Vela IF820, (integrated antenna, or external antenna connector) use a different power table. The script is not able to auto-detect which variant of the Vela IF820 is being flashed, therefore, users must ensure they have modified the script to select the correct firmware version for the variant of the IF820 they are programming. Of note, the Vela IF820 dongle uses the integrated antenna firmware.

For example, to select the external antenna firmware version of the v14.12.12 firmware to flash to the module, open the {} settings.jason file in VSCode. Locate the "ezserial_firmware" line and modify the path provided for the firmware to select the correct path in the VSCode workspace files for the v1.4.12.12-candidate_ext-ant/202309011_ezserial_app_VELA-IF820-EXT-ANT-EVK_141212_v1.4.12.12_download.hex. An example of the modified script is shown below:

{   

 "default_baud": "115200",    

"mini_driver": "${workspaceFolder}/files/minidriver-20820A1-uart-patchram.hex",    

"ezserial_firmware": "${workspaceFolder}/files/v1.4.12.12-candidate_ext-ant/202309011_ezserial_app_VELA-IF820-EXT-ANT-EVK_141212_v1.4.12.12_download.hex",    

"comport_BT900_device1": "/dev/cu.usbserial-AL04XL61"

Please see the Vela IF820 User Guide for additional information about modifying the {} settings.json file.

Does the Vela IF820 support more than one concurrent SPP connection when using EZ-Serial?

No, only a single SPP connection is supported with EZ-Serial. If multiple SPP connections are required, consider using Modus Toolbox.

Transparent data mode can be disabled with bit 1 of the SPPM command as below. This can be used in both text and binary parse modes

(<<) SPPM,M=2

(>>) @R,000A,SPPM,0000

Now when entering a SPP connection instead of going straight into transparent data mode EZ-Serial will remain in command mode and allow the use of commands such as 

Query Connections

(<<) /btqc

(>>) @R,0010,/BTQC,0000,C=01

(>>) @E,002D,BTCS,C=01,A=0016A4001589,T=01,B=00,R=00,S=00

Query peer address

(<<) /btqpa,c=1

(>>) @R,0020,/BTQPA,0000,A=0016A4001589,T=00

Query RSSI

(<<) /btqss,a=58a0238ed80b

(>>) @R,0011,/BTQSS,0502,R=00

You can also send a disconnect command

(<<) /btdis,c=1

(>>) @R,000C,/BTDIS,0000

(>>) @E,0012,BTDIS,C=01,R=0000

To send data in this mode use

(<<) .spps,c=1,d=4C6169726420436F6E6E6563746976697479 

(>>) @R,0010,.SPPS,0000,C=01

Where c = the connection handle and d = is the outgoing payload in hex

When receiving data in this mode you will see

(>>) @E,0016,.SPPD,C=01,D=4D61726B

where c is the connection handle and d is the incoming data in hex

 When plugged into a Windows PC the Vela IF820 DVK will show two comports in Windows device manager.

One com port is a regular UART com port that can be used with EZ-Serial and the other is a HCI com port for flashing firmware.

If its not clear which com port is which you can use Windows device manager. Identify the com ports, right click, select properties and go to the details tab. select the bus reported device description property from the drop down menu.

If the value contains UART0 then this is the HCI com port.

If the value contains UART1 then this is the regular UART com port.

See IF820 DVK SETUP section in the Software User Guide for more information.

Does the Vela IF820 Series - Bluetooth 5.2 Dual-Mode Modules support LE Coded Phy?

Unfortunately not but it does support 2M Phy.

No, the beacon and data rates can be different but at the time of writing there is no benefit from the two data rates being different. If in doubt set them to the same data rate,