Time to breadboard a circuit. I basically used the schematic shown in post #2, but instead of a USB/Serial board, I used an Arduino UNO.
View attachment 122397
The UNO provides the +5V.
I also used a resistor divider (15K/2.2K) from GPIO 8 to ground with the midpoint going to Audio in (IN_L or IN_R, it doesn't matter) and the AGND to the UNO (and board) GND. I was not concerned with high fidelity, but instead, I want to conveniently present a signal to transmit. The Arduino can do this with a simple statement, e.g., tone(8,1000);
I used software serial and this simple terminal program.
Code:
// Simple serial port terminal for testing the BT_Emitter board
// Arduino UNO
#include <SoftwareSerial.h>
#define RxD 2
#define TxD 3
#define BoardSpeed 9600
#define UNOSpeed 9600
SoftwareSerial SSerial(RxD,TxD);
void setup()
{
pinMode(RxD, INPUT);
pinMode(TxD, OUTPUT);
pinMode(8,OUTPUT);
SSerial.begin(BoardSpeed);
Serial.begin(UNOSpeed);
tone(8,1000);
}
void loop()
{
if(Serial.available())
{
SSerial.print((char)Serial.read());
}
if(SSerial.available())
{
Serial.print((char)SSerial.read());
}
}
Now, I could start playing with AT commands - typing them into the serial monitor and observing the response and so on. I tried 9600 first and that (and no other speed) worked.
But where are the AT commands? Am I supposed to guess (I would have). Instead, I searched deep and found a few descriptions in Chinese and ONE place where it was mostly Chinese, but the commands and response were in English. It was as a .jpg so no online translator would help. I am attaching the file - see for yourself.
If anyone wants to provide a full translation, that would be great.
Translation of Image :
Example and explanation of the AT command
Note: the name of the blue-tooth receiver used for the test is Bluetooth Audio, and the MAC address is 0x32a16c6f7f99.
<1>: Test Command
Send : AT+
Note: test communication is normal
Return value: OK+ (return response )
< 2>: system reset
Send : AT+REST
Description: reset
Return value: OK+ (return response )
REST (perform reset operation )
POWER ON (restart )
< 3>: query software version
Send : AT + GMR
Note: Check the software version
Return value: OK+ (return response )
К к к_ввееittertertertervv.x (return software version )
<4>: query connection status
Send : AT + STATUS
Description: search for Bluetooth connection status
Return value: OK+ (return response )
STATUS: x (x=0: no connection, x=1 connected )
< 5>: specify MAC address connection
Send : at + CONADD=0x32a16c6f7f99
Description: specify the MAC address link (here shows the device connected to the MAC-0x32a16c6f7f99 )
Return value: OK+ (return response )
CON: 32a16c6f7f99 (Bluetooth device connected to MAC=0x32a16c6f7f99 )
CONNECTED (successful connection )
<6>: disconnect
Send : AT + DISCON
Description: disconnect the current blue tooth
Return value: OK + DISCON (disconnect operation )
DISCONNECT (disconnected )
< 7>: Bluetooth device
Send : AT + SCAN
Description: search Bluetooth receive device, cycle search and list ? Blue tooth device information found
Return value: OK + SCAN (perform device search )
New Devices: 1 (Find the nth searched device )
MacAdd: 0x32a16c6f7f99 (this device's MAC address is 0x32a16c6f7f99)
Name: Bluetooth Audio (the Bluetooth name for this device is Bluetooth Audio)
ALL Devices=1 (the total number of devices currently searched is 1)
<8>: add automatically connected MAC address
Send : AT + ADDLINKADD=0x32a16c6f7f99
Description: with this command-set, a total of 10 MAC address records can be attached to 10 devices in a sequence.
Set the memory. When the module is started , it will search the MAC address of the device and the MAC address of the recording area.
The address is automatically connected to any one of the MAC addresses of the recording area, and is not connected when the address is not consistent, so as to achieve the specified MAC address connection.
When 10 recording spaces are empty , MAC address filtering is not performed ( by default, this area is empty in the factory).
Return value: OK+ (return response )
ADDLINKADD (execute MAC address memory )
VM_MacAdd 1 =0xb290cb8fa671 (MAC address Oxb290cb8fa671 memory success in VM Zone 1 storage area )
Note: a total of 10 MAC addresses can be stored, according to the storage in the MacAdd 1-MacAdd a total of 10, more than the maximum memory area will addr Mere
- no, no, no, no, no.
< 9>: add the Bluetooth device name for the auto connect
Send : AT + ADDLINKNAME=Bluetooth Audio
Note: with this command setting, specifying the blue tooth name connection, a total of 10 blue tooth names can be added, and 10 devices can be recorded sequentially on the chip.
Memory. When the module is started, it will search the blue tooth name of the device and the blue tooth name of the recording area.
The blue tooth name is automatically associated with any of the blue tooth names in the recording area , and is not associated with any of the blue tooth names in the recording area , so as to achieve the specified blue tooth name connection function . When 10
When all the recording spaces are empty , the blue tooth name is not filtered ( by default, this area is empty in the factory).
Return value: OK+ (return response )
ADDLINKNAME (execute MAC address memory )
VM_Name 1 =Bluetooth Audio (blue tooth name Bluetooth Audio) memory success in VM Zone 1 storage zone )
Note: a total of 10 blue tooth names can be stored, according to the storage in VM_Name1-VM_Name a total of 10, more than the maximum memory area will be an error Nate
More than 10!
<10>: query the auto-connect recording area
Send : AT + VMLINK?
Note: sending this command returns all information recorded in the automatically reconnected MAC and device name zones .
Return value :
ОК+VMLINK( 返 返 回 答 о )
В В_ADD_NUM-1 (Memory number of MAC addresses 0-9 a total of 10 )
В В_NAME_NUM=1 (memory device name address 0-9 total 10 )
Last_Add=0x32a16c6f7f99 (last time even hit the MAC address )
VM_MacAdd0=0xb290cb8fa671 (automatic reconnection Zone 1 MAC address )
VM_Name0=Bluetooth Audio (device name for auto reconnect Zone 1 )
<11>: delete all records in the auto-connect zone
Send : AT + DELVMLINK
Description: Remove all records from the auto reconnect zone (i.e., return to the state where the MAC address and device name are not filtered by default). )
Return value: Delete_Vmlink (perform the Delete operation )
May be this could further help others.