I have an Android app which connectes to a BLE device just fine. It does send only 2 characters to the BLE device to a custom characteristic. Now the Arduino needs to connect to that custom characteristic and listen to those 2 characters. For each character it should perform a task. But its not working currently. The code on the Arduino is currently listening to those characters but not on a custom characteristic. How do I write that code differently for Arduino so it works with that custom characteristic and BLE? I have this code which worked for classic bluetooth:
char junk;
String inputString="";
// the setup function runs once when you press reset or power the board
void setup() {
// initialize digital pin LED_BUILTIN as an output.
//pinMode(LED_BUILTIN, OUTPUT);
Serial.begin(115200);
pinMode(12, OUTPUT);
pinMode(11, OUTPUT);
}
// the loop function runs over and over again forever
void loop()
{
if(Serial.available())
{
while(Serial.available())
{
char inChar = (char)Serial.read();
inputString +=inChar;
Serial.println(inputString);
while
(Serial.available() > 0)
{
junk = Serial.read();
}
if(inputString == "o")
{
digitalWrite(12,HIGH);
}
delay (1000);
digitalWrite(12,LOW);
if(inputString == "c")
{
digitalWrite(11,HIGH);
}
delay(1000);
digitalWrite(11,LOW);
}
inputString = "";}}
However, its not working for BLE and custom characteristic.Anybody knowing what I need to change to make it work for BLE? or steer me in the right direction where to find help to write that code for a custom characteristic with BLE?
Thanks,
Nick
I am not clear what you mean by "a custom characteristic"
It appears that you have the BLE device connected to the hardware serial pins 0 and 1 and are also trying to use the Serial monitor which, on most Arduinos, uses pins 0 and 1 so is not usually a good idea.
What hardware are you using? It looks like you might be using a device like HM-10. I don't think there is any way to use custom characteristics with those modules but it is possible with an Arduino 101.
The HM-10 has only one characteristic exposed and the AT+CHAR0xnnnn command will change the short characteristic UUID used by the HM-10
A complete list of all AT commands can be found in the datasheet
The HM-10 abstracts and packs a Bluetooth Low Energy connection in a serial connection. The original out-of-the-box firmware of the module exposes a BLE peripheral with a proprietary connectivity service (Service UUID: 0000ffe0-0000-1000-8000-00805f9b34fb) that enables bidirectional communication between the module and any other central device that connects to it. The service defines a single characteristic (Characteristic UUID: 0000ffe1-0000-1000-8000-00805f9b34fb) that stores 20 bytes of unformatted data:
Ah, I had seen that in the datasheet but thought that "change characteristic value" meant writing a value to the characteristic. That second link makes it more clear.
No, its not HM10 rather one from Adafruit Feather 32u4 which has a ble radio and an Arduino all on one board. But its all so custom that I can't understand it anymore..the above code worked for a classic bluetooth device. Now with the new one its a BLE device and that code wont work anymore..I had to implement a new code which I got from Adafruit but that also is so strange..I just wonder if there is extra code for the Arduino needed if one was to create its own characteristic..cause I've seen the healththermometer code from Adafruit and this one has some strange uuid's in it and is just plain weird..completely different from the code above..that's why I'm asking if anyone knows about that issue and has a solution for an Arduino code for custom characteristic?
Thanks,
Nick