Echo ATS-BT Quick Start Guide - Echo Support Center

Hardware Setup

Connect your ATS-BT module

ATS-BT Console

Configure without the terminal

Terminal Config

Set up your serial connection

First Commands

Test basic functionality

Bluetooth Connections

Connect A2DP and LE Audio devices

Command Reference

Complete command guide

Overview

The ATS-BT (Acoustic Test System - Bluetooth) module is a Bluetooth communication module controlled through simple text commands. Send commands over a serial connection, and the module handles all the Bluetooth complexity for you. Perfect for acoustic testing, audio development, and test automation. The ATS-BT module features S/PDIF digital I/O with connectivity through micro BNC ports. It can run stand-alone and will connect to any S/PDIF capable interface.

The ATS-BT utilizes the IDC777 Bluetooth module from IOT747, providing advanced Bluetooth 5.4 capabilities including LE Audio (LC3 codec with Auracast and Unicast) and Classic Bluetooth with aptX support.For detailed IDC777 technical specifications and documentation, visit the IOT747 documentation page.

Hardware Setup

Figure 1: ATS-BT Module Front and Rear Views

Connection Steps

Connect USB Power

Connect a USB Type-C cable from the ATS-BT module to your host computer. The module is powered via USB - no external power supply needed.

Connect S/PDIF Output

Connect the OUTPUT of the BT module to the INPUT on your ATS or S/PDIF interface.

Connect S/PDIF Input

Connect the INPUT of the BT module to the OUTPUT on your ATS or S/PDIF interface.

The TX/RX swap is intentional — the module receives what you transmit and vice versa.

Figure 2: ATS rear view showing where ATS-BT connects

Mounting: The ATS-BT includes mounting holes for secure installation. See the mounting holes drawing for dimensions and hole positions.

LED Status Indicators

LED State	Status	Description
Solid White	Initializing	Module is starting up
Rapid Blinking	Pairing Mode	Ready to pair with devices
Slow Blinking	Connected/Idle	Bluetooth connected or waiting
Off	No Power/Idle	Check USB connection

Configure with the ATS-BT Console

The fastest way to set up the ATS-BT is the free ATS-BT Console app for Windows. It connects over the same USB cable and replaces the terminal workflow below — configure everything point-and-click, no UART commands required:

Switch device roles — Audio Sink, Audio Source, LE Audio, and Auracast broadcast
Scan and pair — discover nearby Classic and LE Audio devices and pair them
Monitor live links — watch connection state and audio streams in real time
Built-in command console — drop down to raw UART commands whenever you want

Figure 3: ATS-BT Console dashboard

Download ATS-BT Console

Grab the Windows installer from the Software Downloads page.

The rest of this guide covers the UART command route — the right choice for automation, scripting, or macOS/Linux hosts. The ATS-BT Console is Windows-only.

Terminal Configuration

Windows (PuTTY)
macOS/Linux
Alternative (Hercules)

Windows Setup with PuTTY

Download PuTTY

Download PuTTY from putty.org if you don’t have it already.

Find COM Port

Open Device Manager (press Windows+X, then M) and look under “Ports (COM & LPT)”. Note your COM port number (e.g., COM3 or COM4) - it will be listed as “USB Serial Device”.

Configure PuTTY

Open PuTTY and configure:

Connection type: Serial
Serial line: Your COM port (e.g., COM3)
Speed: 115200
Click Open

For the best user experience, configure these terminal settings as shown in Figure 4 below

Local echo: Force on (so you can see what you type)
Implicit CR in every LF: On (proper line endings)
Implicit LF in every CR: On (proper line endings)

Figure 4: PuTTY terminal configuration

To save your configuration:

Enter all settings (Serial, COM port, 115200 baud)
Type “ATS-BT” in “Saved Sessions”
Click “Save”

Next time, just double-click “ATS-BT” from the saved sessions list.

macOS/Linux Terminal Setup

Find Serial Port

Open Terminal and run:

ls /dev/tty.usb* # macOS
ls /dev/ttyUSB* # Linux

Note your device path (e.g., /dev/tty.usbserial-1420 or /dev/ttyUSB0)

Connect with Screen

Use the built-in screen command:

screen /dev/tty.usbserial-1420 115200

Replace with your actual device path.

Exit Screen

To exit screen when done:

Press Ctrl+A then K
Confirm with Y

Alternative Tools:

minicom: minicom -D /dev/ttyUSB0 -b 115200
picocom: picocom -b 115200 /dev/ttyUSB0
CoolTerm: GUI application for macOS

Essential Commands

Now let’s verify your module is working correctly. Commands are case-insensitive.

Module Info
Device Discovery
Status Check

Basic Module Information

VERSION

ATS-BT
Copyright 2025 Echo Audio Test + Measurement
Firmware: 1.0.3

Get Bluetooth Address

GET LOCAL_ADDR

LOCAL_ADDR=112233445566
OK

View Configuration

CONFIG

[Shows all current settings including device name, audio config, and features]
OK

Scan for Classic Bluetooth

INQUIRY 10

PENDING
INQUIRY 001122334455 "iPhone" 2C0404 -45 dBm
INQUIRY AABBCCDDEEFF "Galaxy Buds" 2C0404 -62 dBm
OK

Understanding the response:

Address: 12-character Bluetooth address (001122334455)
Name: Device name in quotes (“iPhone”)
CoD: Class of Device (2C0404)
RSSI: Signal strength in dBm (-45) - closer to 0 is stronger

Scan for BLE Devices

SCAN 5 OFF 3

PENDING
SCAN 3 AABBCCDDEEFF 0 0x3 -48
OK

Scan filters:

0: No filter (all devices)
2: LE Auracast Broadcasters
3: LE Unicast Receivers

Connection Status

STATUS

STATE CONNECTABLE[ON] DISCOVERABLE[ON] ADVERTISING[ON]
SCAN_UNI[OFF] AUTOCONN[OFF] OPENANY[OFF]

Flag	Meaning	Typical State
CONNECTABLE	Accepts incoming connections	ON
DISCOVERABLE	Visible to other devices	ON
ADVERTISING	Broadcasting BLE availability	ON
SCAN_UNI	Unicast scanning	OFF
AUTOCONN	Auto-reconnect to paired	OFF
OPENANY	Accept any connection	OFF (security)

List Paired Devices

LIST

001122334455 "iPhone"
AABBCCDDEEFF "Galaxy Buds"
OK

Success! If you see proper responses to these commands, your ATS-BT module is working correctly and ready for Bluetooth connections.

Transmit and Receive Modes

The ATS-BT can operate as an audio transmitter or a receiver, but not both at the same time. The direction is set by the PROFILES configuration, and the module must be in the correct mode before you open an audio stream.

Transmit (TX)

ATS-BT sends audio out over Bluetooth — e.g. streaming its S/PDIF input to earbuds or a phone using LE Audio (OPEN ... UTX) or A2DP source.

SET PROFILES=ON 0 1 0 1 1 1 1
WRITE
RESET

Receive (RX)

ATS-BT receives audio from a phone or other source and plays it out on S/PDIF (A2DP sink). This is the factory default.

SET PROFILES=ON 1 0 1 0 1 1 1
WRITE
RESET

A PROFILES change only takes effect after WRITE followed by RESET. Check the current mode any time with CONFIG and read the PROFILES= line.

Bluetooth Connections

Classic Bluetooth (A2DP)
BLE Audio (LE Audio)

Connecting to Classic Bluetooth Devices

Perfect for headphones, speakers, and traditional Bluetooth audio devices.

Put Device in Pairing Mode

Enable pairing mode on your headphones/speaker (usually holding the power button).

Scan for Devices

INQUIRY 5

Note the address of your device from the results.

Pair with Device

PAIR 001122334455

PENDING
PAIR_OK 0 001122334455

Open A2DP Connection

OPEN 001122334455 A2DP

PENDING
OPEN_OK 10 A2DP 001122334455
OPEN_OK 11 AVRCP 001122334455
ABS_VOL 11 59

Link IDs Explained:

10: A2DP audio stream (first digit = device, second = profile)
11: AVRCP control channel
Use these IDs for subsequent commands

Start Audio Playback

MUSIC 11 PLAY

OK
ABS_VOL 11 59
A2DP_STREAM_START 10

Playback Control Commands

Command	Description	Example
MUSIC <id> PLAY	Start playback	`MUSIC 11 PLAY`
MUSIC <id> PAUSE	Pause playback	`MUSIC 11 PAUSE`
MUSIC <id> STOP	Stop playback	`MUSIC 11 STOP`
VOLUME <id> <level>	Set volume (0-127)	`VOLUME 11 64`

Connecting to LE Audio Devices

For next-generation Bluetooth devices supporting LE Audio with LC3 codec.

OPEN ... UTX transmits audio from the ATS-BT, so the module must be in transmit mode first (SET PROFILES=ON 0 1 0 1 1 1 1, then WRITE and RESET). See Transmit and Receive Modes.

Scan for BLE Devices

SCAN 5 OFF 3

PENDING
SCAN 3 AABBCCDDEEFF 0 0x3 -48
OK

Filter options:

3: LE Unicast Receivers (headphones/earbuds)
2: LE Auracast Broadcasters
0: All BLE devices

Pair with BLE Device

PAIR_LE AABBCCDDEEFF 0

PENDING
PAIR_OK_LE AABBCCDDEEFF

Address type parameter:

0 — Public address (most LE Audio earbuds, e.g. Galaxy Buds 2 Pro)
1 — Private/random resolvable address (most modern smartphones using LE Privacy, e.g. Pixel 8+)

Check the address type column in your SCAN results to choose the right value. For example, SCAN 3 AABBCCDDEEFF 0 0x3 -48 shows address type 0 (public), so use PAIR_LE AABBCCDDEEFF 0. If you see 0x1 instead, use PAIR_LE AABBCCDDEEFF 1.

The “PAIR_OK_LE” confirms successful Low Energy pairing. Omitting the address type returns [BT Error] Wrong parameter.

Pair Second Earbud (Coordinated Sets)

If your device is a set of earbuds, use SCAN_RSI to find and pair the second earbud:

SCAN_RSI 5 AABBCCDDEEFF 0

PENDING
SCAN_RSI FFEEDDCCBBAA
OK

Then pair the second earbud:

PAIR_RSI FFEEDDCCBBAA

PENDING
PAIR_OK_LE FFEEDDCCBBAA

The 0 after the address is the address type (0 = public). The second earbud will auto-connect when you open a UTX stream to the first earbud.

Open BLE Connection

OPEN AABBCCDDEEFF BLE 0

PENDING
OPEN_OK 14 BLE AABBCCDDEEFF

The 0 after BLE is the address type (0 = public address).

Open Audio Stream

OPEN AABBCCDDEEFF UTX 0 0

PENDING
OPEN_OK 17 UTX AABBCCDDEEFF
LC3_MEDIA_START 17 SOURCE 8 CONTEXT 4
ABS_VOL 17 136

Audio streaming begins automatically when the UTX link opens — no separate MUSIC command is needed.UTX parameters:

First 0: Address type (0 = public)
Second 0: Connection info — 0 for music, 1 for voice

Stream types:

UTX 0 0: Unicast transmit (music)
UTX 0 1: Unicast transmit (voice)
URXM: Unicast receive (music)
URXV: Unicast receive (voice)

To stop a UTX audio stream, close the link with CLOSE <link_id> (e.g., CLOSE 14).

Verify Stream Status

STATUS

STATE CONNECTABLE[ON] DISCOVERABLE[IDLE] ADVERTISING[ON]
LINK 14 CONNECTED BLE AABBCCDDEEFF MTU 250
LINK 17 CONNECTED UTX AABBCCDDEEFF STREAMING LC3 MEDIA
SNK_RATE 48000 SNK_SDU_INT 10000 SNK_SDU_SIZE 100
SNK_RTN 5 SNK_P_DELAY 40000 SNK_MAX_LAT 95
OK

LC3 Stream Parameters

Parameter	Value	Description
SNK_RATE	48000	48kHz sample rate
SNK_SDU_INT	10000	10ms packet interval
SNK_SDU_SIZE	100	100 byte packets
SNK_RTN	5	5 retransmissions
SNK_MAX_LAT	95	95ms max latency

Success! Your BLE Audio stream is now active using the efficient LC3 codec!

Command Reference

Basic Commands

HELP

Shows all available commands

HELP

VERSION

Display firmware version

VERSION

CONFIG

Shows current configuration

CONFIG

STATUS

Shows connection status

STATUS

LIST

List paired devices

LIST

GET LOCAL_ADDR

Get module’s Bluetooth address

GET LOCAL_ADDR

Discovery Commands

INQUIRY

Search for Classic Bluetooth devicesSyntax: INQUIRY <time>Example:

INQUIRY 10  # Scan for 10 seconds

SCAN

Search for BLE devicesSyntax: SCAN <time> [format] [filter]Filters:

0: No filter
2: Auracast Broadcasters
3: Unicast Receivers

Example:

SCAN 5 OFF 3  # Scan LE Unicast devices

SCAN_RSI

Find the second earbud in a coordinated setSyntax: SCAN_RSI <time> <bt_addr> <addr_type>Example:

SCAN_RSI 5 AABBCCDDEEFF 0  # Find set member (0=public addr)

Connection Commands

PAIR

Pair with a Classic Bluetooth deviceSyntax: PAIR <bt_addr>Example:

PAIR 001122334455

PAIR_LE

Pair with a Bluetooth Low Energy device (required before OPEN UTX LE Audio streaming)Syntax: PAIR_LE <bt_addr> <addr_type>Address types:

0 — Public address (most LE Audio earbuds)
1 — Private/random resolvable address (most modern smartphones)

Examples:

PAIR_LE AABBCCDDEEFF 0   # Galaxy Buds 2 Pro and similar earbuds
PAIR_LE 50C0F02093B6 1   # Pixel / Android phones using LE Privacy

The address type must match what SCAN reports for that device. Omitting it returns [BT Error] Wrong parameter.

UNPAIR

Remove device from pair listSyntax: UNPAIR [bt_addr]Examples:

UNPAIR 001122334455  # Specific device
UNPAIR               # All devices

PAIR_RSI

Pair with the second earbud found via SCAN_RSISyntax: PAIR_RSI <bt_addr>Example:

PAIR_RSI FFEEDDCCBBAA

OPEN

Open profile connectionSyntax: OPEN <bt_addr> <profile> [addr_type] [connection_info]Profiles: A2DP, AVRCP, BLE, UTX, URXM, URXV, etc.Examples:

OPEN 001122334455 A2DP        # Classic A2DP
OPEN AABBCCDDEEFF BLE 0       # BLE link (0=public addr)
OPEN AABBCCDDEEFF UTX 0 0     # Unicast music (0=music)
OPEN AABBCCDDEEFF UTX 0 1     # Unicast voice (1=voice)

CLOSE

Close connectionSyntax: CLOSE <link_id>Example:

CLOSE 10

Configuration Commands

PROFILES

Set the module’s operating direction. The IDC777 can be a transmitter or a receiver, not both at once.Syntax: SET PROFILES=ON <hfp> <aghfp> <a2dp_snk> <a2dp_src> <avrcp> <ble> <spp>Common values:

SET PROFILES=ON 0 1 0 1 1 1 1   # Transmit (LE Audio UTX / A2DP source)
SET PROFILES=ON 1 0 1 0 1 1 1   # Receive (A2DP sink) — factory default

Follow any PROFILES change with WRITE then RESET. Do not enable both a2dp_snk and a2dp_src at the same time — it makes the module unstable and it will reset when a stream opens.

Audio Control

MUSIC

Control playback (Classic A2DP and Auracast only)Syntax: MUSIC <link_id> <action>Actions: PLAY, PAUSE, STOPExample:

MUSIC 11 PLAY

The MUSIC command works with A2DP, AVRCP, and Auracast (BRX1/BRX2) links. It does not apply to UTX unicast streams — those start audio automatically when the link opens. Use CLOSE <link_id> to stop a UTX stream.

VOLUME

Set volume levelSyntax: VOLUME <link_id> <level>Range: 0-127Example:

VOLUME 11 64  # 50% volume

Contact Echo for info or support.

​Quick Navigation

Hardware Setup

ATS-BT Console

Terminal Config

First Commands

Bluetooth Connections

Command Reference

​Overview

​Hardware Setup

​Connection Steps

​LED Status Indicators

​Configure with the ATS-BT Console

Download ATS-BT Console

​Terminal Configuration

​Windows Setup with PuTTY

​macOS/Linux Terminal Setup

​Hercules Terminal (Windows)

​Essential Commands

​Basic Module Information

​Get Bluetooth Address

​View Configuration

​Scan for Classic Bluetooth

​Scan for BLE Devices

​Connection Status

​List Paired Devices

​Transmit and Receive Modes

Transmit (TX)

Receive (RX)

​Bluetooth Connections

​Connecting to Classic Bluetooth Devices

​Playback Control Commands

​Connecting to LE Audio Devices

​LC3 Stream Parameters

​Command Reference

HELP

VERSION

CONFIG

STATUS

LIST

GET LOCAL_ADDR

INQUIRY

SCAN

SCAN_RSI

PAIR

PAIR_LE

UNPAIR

PAIR_RSI

OPEN

CLOSE

PROFILES

MUSIC

VOLUME

Quick Navigation

Overview

Hardware Setup

Connection Steps

LED Status Indicators

Configure with the ATS-BT Console

Terminal Configuration

Windows Setup with PuTTY

macOS/Linux Terminal Setup

Hercules Terminal (Windows)

Essential Commands

Basic Module Information

Get Bluetooth Address

View Configuration

Scan for Classic Bluetooth

Scan for BLE Devices

Connection Status

List Paired Devices

Transmit and Receive Modes

Bluetooth Connections

Connecting to Classic Bluetooth Devices

Playback Control Commands

Connecting to LE Audio Devices

LC3 Stream Parameters

Command Reference