The quintessential BlueTooth speakers

Module overview FSC-DB102 Ver: 1.4 (further product). Module based FSC-BT1026Cwhich in turn works on the basis of a three-core Audio processor QCC3034.

What do we need from the equipment?

No.

Equipment

Purpose

one

micro USB cable

To supply power to the product and control the behavior of the firmware

2

FSC-DB102 Ver: 1.4

Product

3

Internet access

For the extraction of documentation

four

DMM

To find ground on the PCB

5

Microscope

To identify real chips on PCB

6

Calipers

For dimensioning PCB mounting holes

7

Smartphone with Android

To send audio traffic

eight

Logic Analyzer

For I2S bus diagnostics

9

Headphones with Audio Jack 3,5mm

For direct sound emission

ten

LapTop/NetTop/DeskTop

For product diagnostics and configuration

What do you need from software?

#

Software

Purpose

one

TeraTerm/Putty/Terminal v1.9b

Utilities for sending AT commands over a serial port

2

PDF Viewer

To read Vendor’s documentation

3

Serial Bluetooth Terminal 1.36

Mobile App for Bluetooth Chat

four

Tor Browser

To download documentation from the Qualcomm website

5

Inkscape vector editor

For parsing and analyzing I2S waveforms

6

Driver for CP2104 chip

To connect to a computer

7

OS Windows

What do you need from the documentation?

doc name

pages

Ver

Content

FSC-DB102 BT100x TWS User Guide V1.0

7

1.0

Description of the appearance of the board

FSC-BT1026x Bluetooth 5.1 Dual Mode Module

38

1.5

FSC-BT1026C V1.2 module pinout

FSC-BT100X Sink Programming User Guide

35

3.5

list of available AT commands

FSC-DB102(BT1006A) DK Board SCH

one

1.4

Module circuitry

Prologue

Now it’s very easy to do bluetooth column literally from improvised components. Sold ready bluetooth Audio modules. Here is an example module FSC-DB102 Ver: 1.4

FSC-DB102 Ver: 1.4
FSC-DB102 Ver: 1.4

The module is installed on the board FSC-BT1026C V1.2. You can see the chip under the lens QCC3024

FSC-BT1026C V1.2
FSC-BT1026C V1.2

Here is his wiring diagram.

block diagram

Since the board must be installed vertically on the stand, I had to measure the dimensions with a caliper

When receiving a printed circuit board (PCB), the first question that an electronic engineer should ask himself is: “where is the ground (GND) on this board?”. It can be called DMM(th)

The most accessible places for grounding
The most accessible places for grounding

Similarly nutrition

To turn on the module, just apply power to any USB micro (J1 or J6) and press and hold the Play/Pause (K1) button. The red LED0 will flash. Next, take a smartphone, go to Android ->Settings->Bluetooth. Select Bluetooth on.

Listed AVAILABLE DEVICES appears FSC-BT1026C-LE. The phone will prompt you to pair with FSC-BT1026C. Click PAIR.

After that, the red LED0 on the module has already begun to glow continuously. Now you can open YouTube and listen to the video through the headphones connected to the board FSC-DB102 Ver: 1.4. You can change the sound volume from your phone. You can also stop the video with the PLAY/PAUSE (K1) button on the blue PCB of the module.

Also, when connected via USB via connector J6, COM3. At bit rate 115200 bit/s you can see what the module sends to UART log.

The first thing that comes to mind is what can be done based on this Bluetooth module as a column that will log listened tracks to the SD card. Column with black box.

Communication and interaction with the module is carried out through the AT-Commands protocol over UART. You can use the utility Terminal v1.9b

You can also set up TeraTerm for automatic appending carriage carriage and return to the beginning of the line. Plus, you need to activate the software echo, since the firmware does not send an echo to the UART

Next, you can see that the device is responding to AT commands sent via TeraTerm


Audio transmission over I2S

By itself, the module does not send anything to I2S out of the box, even when the stream is enabled. So I2S needs to be configured somehow. There is an AT command for that. AT-I2SCFG

If you send a command to the UART AT+I2SCFG=65 (65=0x41=0b0100_0001), then the FSC-BT1026C module will become the master on the bus I2S at a sample rate of 48kHz and will send 32-bit PCM samples on the wire PCM-OUT. The bit frequency is 3.012 ….3.086 MHz

At the same time, when sound is transmitted to I2S, sound is not transmitted to the headphones on Audio Jack 3.5mm, which is inconvenient for debugging.

Text transmission over SSP (Serial Port Profile)

The module can transmit not only sound but also text data. In SSP mode, the blue LED1 is lit on the board. You need to install the application on your mobile phone Serial Bluetooth Terminal 1.36

Get Bluetooth chat (ik) at 10 meters.

Project ideas based on the FSC-BT1026 module

1–Device auto-dialer to phone numbers, which will automatically speak some sound and reset or a hardware auto-responder.

2–Bluetooth speaker with content logging function. The title of the YouTube video.

3–Remote control via SSP from phone.

4–Bluetooth SSP chat within 10 meters.

Conclusion

The thing is interesting. May be useful for prototyping.

Dictionary

Acronym

Decryption

AT

ATtention

PCM

pulse code modulation

SSP

Serial Port Profile

USB

Universal Serial Bus

LED

Light emitting diode

FSC

FeasyCom

PCB

printed circuit board

DMM

digital multimeter

SD

Secure Digital

UART

Universal asynchronous receiver-transmitter

I2S

Inter-IC Sound

Links

https://aliexpress.ru/item/4000166437470.html

https://www.youtube.com/watch?v=oVu2K6WutUk&t=23s

https://www.youtube.com/watch?v=kgOHkWo7wuw

https://www.feasycom.net/bluetooth-module-development-board