Hi, I’m having trouble getting my app to display any data received via BLE in my app. I’ve only been able to get an error code if I use call – BLE1’s Receive String – in which case the error reads: Can’t read the characteristic provided error – however I believe that’s not relevant, because my data is being sent via notify not read in my code so it should populate with a “when BLE1 characteristic change” if I understand correctly.
Here’s a screenshot of the relevant blocks:
Here’s the relevant parts of my Arduino code:
// This function builds a plain-text string with each schedule
// formatted as "HH:MM,runTime,settleTime,dose" (each schedule on a new line)
// It then prints the string along with the notify characteristic UUID,
// sets it as the value for the response characteristic, and sends a notify.
void sendSchedulesToApp() {
String data = "";
for (int i = 0; i < scheduleCount; i++) {
// Format time with leading zeros for consistency
String hourStr = (schedules[i].hour < 10 ? "0" : "") + String(schedules[i].hour);
String minuteStr = (schedules[i].minute < 10 ? "0" : "") + String(schedules[i].minute);
String line = hourStr + ":" + minuteStr + "," +
String(schedules[i].runTime) + "," +
String(schedules[i].settleTime) + "," +
String(schedules[i].dose);
data += line;
if (i < scheduleCount - 1) {
data += "\n"; // Newline separates each schedule
}
}
// Debug print: show the UUID and the exact data being sent
Serial.print("Sending schedule data via notify on characteristic ");
Serial.print(RESPONSE_CHARACTERISTIC_UUID);
Serial.print(": ");
Serial.println(data);
responseChar->setValue(data.c_str());
responseChar->notify();
}
void Setup() {
//Initialize BLE
responseChar = pService->createCharacteristic(
RESPONSE_CHARACTERISTIC_UUID,
BLECharacteristic::PROPERTY_NOTIFY
);
responseChar->addDescriptor(new BLE2902());
I can call the function using the app via transmit string, but no matter what I’ve tried I cannot get the response(notify) string to populate in the app. Any help would be massively appreciated, thanks!
proof of the Arduino receiving GETSCHEDULES:
