You can select the relevant characteristics as they’re listed in the datasheet (FFE4 and FFE9). With these settings, I can communicate bidirectionally, the issue comes with sending data from my microcontroller to the app unfortunately.
Hi, I downloaded Serial Bluetooth Terminall APP and managed to go to Custom LE profile, but cannot figure out how to give those UUIDs. It is not possible to write anything to service UUID, if I click it, app tries to connect, but fails.
It appears that I have the same problem as you. You can send configuration commands (TTM) via Bluetooth, but trying to send something from MCU (I have Seeduino XIAO) via TX,RX fails.
I think someone in Seeedstudio should explain what is the problem here
This code needs to be modified a bit, as follows. @harris.shallcross@heikki728
1, the wakeup pin has to pull down the delay by about 3ms before sending data to the serial port
2, If you want faster data response, you can modify the connection interval a bit via the AT command. You can send this data to modify the parameters, do not immediately pull up after sending the data, also delay 1~3ms.
I’ve added delays between the high to low and low to high transition of 5ms. I can now receive data on my phone but it seems to receive twice and every two seconds, even though I’m sending it once and every one second.
You can see in the time stamps above that the first three messages are every second but then it becomes every two seconds.
I then tried to change the CIT to 20ms by sending the TTM command after I had connected and I still get the same issue - messages send after 2s and come in pairs!
Hi All,
I am also using this same module for my real time temperature update in to my android phone and i m having issues of lag from the data on serial terminal app, i try code with hm10 ,hc05 and other esp modules work fine without delay.
Why this module is giving me delay over the time?
Any idea or setting related to arduino programing
I thought it is cheap so i bought it for my project. that i usually did with HC-05. HC-06 but, it worked not stably, i controlled it by arduino Mega 256, with 3.3 v supply. the longest time for sending data is 2 Mins. it disconnected after 5 second usually .
here is my code (really simple, i used all default )
Do you know the reason for not work long time? Please guide me. Thanks for your time.
And do you know how to fast reconnect from Android App. Sometime failed to reconnect .
void setup() {
// initialize both serial ports:
Serial1.begin(115200);
pinMode(14, OUTPUT); // PDN :14
pinMode(15, OUTPUT); // WAKEUP:15
digitalWrite(14, 1); // make sure high before low
digitalWrite(15, 1); // make sure high before low
delay(100);
digitalWrite(14, 0); // stop Sleep
digitalWrite(15, 0); // before send command
delay(5);
Serial1.write(“TTM”); //
}
void loop() {
digitalWrite(15, 1); // go to sleep
delay(100); // interval time between send
digitalWrite(15, 0); // wakeup before send
delay(5); // delay before send
Serial1.write(“Hello there, are you there”);
delay(10); // make sure data are sent; 1ms also OK
}
Problem is that i could not connect BT4502 with my Andrdoid phone thought new APP. After i debuged i saw “BLUETOOTH_LE_TIO_CHAR_TX_CREDITS” is not correct. (at SerialSocket, line 58-59), i tried to modify this number (i modified with number i received thought “Serial Bluetooth Terminal”), but was not successed. TX_CREDITS called by Mr Kai-morich, i dont understand what is this,How can i get that number.
I know it long text, and bother you much, but can you check this App ?
If you know some Open source APP can connect with HM-BT4502 , please tell me.
hi
I wish to receive data from HM-BT4502 module on my BLUETOOTH SERIAL APP (which everyone use)
I am using Arduino Uno for it, can you share the code.
i have tried a lot but I don’t get it.
Hello, I have 2 HM-BT4502B modules. I can connect these modules one by one to the mobile and i can send or recieve data. But I can’t connect the two devices to each other. I don’t want to use an external MCU. HM-BT has programmable CMT4502(internal Arm Cortex M0). I couldn’t find any documentation or example on the internet to solve my connection problem (even one of the rare people using HM-BT4502). Can someone help me to connect two HM-BT4502s together?