Hi guys,
I've recently bought a pair of these boards from Aliexpress to experiment with their TWS function:
https://www.aliexpress.com/item/1005002070925714.html?spm=a2g0o.order_list.0.0.21ef1802RYefcz
Sound quality is great, with none of the noise problems some other BT boards have. Seems like they want 8 ohm drivers though, you can make them cut out rather easily trying to drive 4 ohms at 21v input.
They have the BK chip's serial communications port made available for setting of various parameters, including the BT name.
I am using an Arduino Nano and the SoftwareSerial library to implement a USB-to-serial converter, following the instructions here:
https://maker.pro/arduino/projects/how-to-change-the-bluetooth-module-name-easily-with-arduino
However, I can not seem to achieve bidirectional communications. Using CoolTerm on MacOS, I can connect to the serial port, and see the Arduino script's welcome message ("Type some AT commands!") and also the BK chip's status messages ("BT_P", "BT_CN" etc). But I get no response when I try to send AT+ or COM+ commands to the BK chip - not even "ERROR". Additionally, the messages from the BK chip seem to arrive with extra line breaks in them, like this:
B
T
_CN
B
T
_P
I have all the serial port settings as described in the BK chip datasheet. Has anyone had experience trying to configure these chips via the serial port, if so can you tell what I'm doing wrong? Seems like, if I can read the messages the board is sending, it should be able to read what I am sending - but those extra line breaks make me think something is not quite right...
I've recently bought a pair of these boards from Aliexpress to experiment with their TWS function:
https://www.aliexpress.com/item/1005002070925714.html?spm=a2g0o.order_list.0.0.21ef1802RYefcz
Sound quality is great, with none of the noise problems some other BT boards have. Seems like they want 8 ohm drivers though, you can make them cut out rather easily trying to drive 4 ohms at 21v input.
They have the BK chip's serial communications port made available for setting of various parameters, including the BT name.
I am using an Arduino Nano and the SoftwareSerial library to implement a USB-to-serial converter, following the instructions here:
https://maker.pro/arduino/projects/how-to-change-the-bluetooth-module-name-easily-with-arduino
However, I can not seem to achieve bidirectional communications. Using CoolTerm on MacOS, I can connect to the serial port, and see the Arduino script's welcome message ("Type some AT commands!") and also the BK chip's status messages ("BT_P", "BT_CN" etc). But I get no response when I try to send AT+ or COM+ commands to the BK chip - not even "ERROR". Additionally, the messages from the BK chip seem to arrive with extra line breaks in them, like this:
B
T
_CN
B
T
_P
I have all the serial port settings as described in the BK chip datasheet. Has anyone had experience trying to configure these chips via the serial port, if so can you tell what I'm doing wrong? Seems like, if I can read the messages the board is sending, it should be able to read what I am sending - but those extra line breaks make me think something is not quite right...
update: I realised the BT board uses 3.3v logic and the Arduino uses 5v, so I inserted some voltage dividers into the circuit to match those levels. Still no dice, exact same behaviour now.
I also used the "view hex" function in Coolterm to look at the raw hex data being sent by the board, and there is literally an extra "0A0D" = "line break + carriage return" character between every normal character. Seems completely weird to me. Possible I just have a board with bad firmware on it, that isn't functioning correctly?
I also used the "view hex" function in Coolterm to look at the raw hex data being sent by the board, and there is literally an extra "0A0D" = "line break + carriage return" character between every normal character. Seems completely weird to me. Possible I just have a board with bad firmware on it, that isn't functioning correctly?