Hey all,
I’m trying to send sensor readings over BLE to an app I created using MIT app inventor and something is not working, my guess is I’m missing something in my sketch or misunderstanding on how BLE works.
This is the sketch I use:
#include <ArduinoBLE.h>
#define BLE_BUFFER_SIZES 20
#define BLE_DEVICE_NAME "DTD"
#define BLE_LOCAL_NAME "DTD_1"
int red = 11;
int green = 10;
int blue = 9;
float sensor = A0;
float cf = 19.5; // caliberation factor
float pressureReading;
BLEService BLESensors("00001101-0000-1000-8000-00805F9B34FB");
BLECharacteristic pressureBLE("2A19", BLERead | BLENotify | BLEBroadcast, BLE_BUFFER_SIZES);
void setup()
{
LedColor (0,255,0);
Serial.begin(9600);
while (!Serial);
// begin initialization
if (!BLE.begin())
{
Serial.println("starting BLE failed!");
while (1);
}
// set the local name peripheral advertises
BLE.setDeviceName(BLE_DEVICE_NAME);
BLE.setLocalName(BLE_LOCAL_NAME);
BLE.setAdvertisedService(BLESensors);
BLESensors.addCharacteristic(pressureBLE);
BLE.addService(BLESensors);
// start advertising
BLE.advertise();
Serial.println(("Bluetooth device active, waiting for connections..."));
}
void loop()
{
// listen for BLE peripherals to connect:
BLEDevice central = BLE.central();
// if a central is connected to peripheral:
if (central) {
Serial.print("Connected to central: ");
// print the central's MAC address:
Serial.println(central.address());
// while the central is still connected to peripheral:
while (central.connected())
{
LedColor (0,0,255);
for (int i=0;i<10;i++)
{
float Reading = analogRead(sensor);
pressureReading = pressureReading + Reading;
delay (50);
}
pressureReading = pressureReading / 10;
pressureReading = (pressureReading * 5.0) / 1023.0;
pressureReading = pressureReading * cf;
Serial.println(pressureReading);
pressureReading = 0;
}
// when the central disconnects, print it out:
Serial.print(F("Disconnected from central: "));
Serial.println(central.address());
LedColor (255,0,0);
}
}
void LedColor(int redL, int greenL, int blueL)
{
analogWrite(red, redL);
analogWrite(green, greenL);
analogWrite(blue, blueL);
}
and this is a small app I created to check if I recive the data:
for some reason I see the sensor reading in the monitor but not in the app.
).
