Bluno General Arduino

Only get data on iOS app if Serial Monitor is open

userHead info 2018-02-09 07:40:21 1998 Views2 Replies
Ive run into an issue that seems to be common but unanswered. I have a sketch that sends data from the bluno nano to an iOS app (BlunoTerminal or the DFRobot BlunoTestDemo app).

The app gets(null) until I open the serial monitor, then I start getting my data. If I power the bluno from a USB-battery pack I get null but worst of all, I cant open a serial monitor in order to get my data because the bluno is not connected to a computer.

Can anyone offer a solution for this?

Here is my sketch with a hard coded data value of 454:
Code: Select all
byte statusLed    = 13;
byte sensorInterrupt = 0;  // 0 = digital pin 2
byte sensorPin       = 2;
float calibrationFactor = 4.5;
volatile byte pulseCount;  
float flowRate;
unsigned int flowMilliLitres;
unsigned long totalMilliLitres;
unsigned long oldTime;

void setup(){
  pinMode(statusLed, OUTPUT);
  digitalWrite(statusLed, HIGH);  // We have an active-low LED attached
  pinMode(sensorPin, INPUT);
  digitalWrite(sensorPin, HIGH);
  pulseCount        = 0;
  flowRate          = 0.0;
  flowMilliLitres   = 0;
  totalMilliLitres  = 0;
  oldTime           = 0;
  attachInterrupt(sensorInterrupt, pulseCounter, FALLING);

void loop(){
   if((millis() - oldTime) > 5000) {   // Only process counters once per second
    flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor;
    oldTime = millis();
    flowMilliLitres = (flowRate / 60) * 1000;
    totalMilliLitres += flowMilliLitres;
    unsigned int frac;
    frac = (flowRate - int(flowRate)) * 10;

    pulseCount = 0;
    attachInterrupt(sensorInterrupt, pulseCounter, FALLING);

void pulseCounter(){
void sendOverBLE() {
  int mystring;
  mystring = int(454);
  Serial.println(mystring);//send what has been received
  Serial.println();   //print line feed character

2018-09-15 15:05:26 I am also having this problem. Did you find a solution? userHeadPic cosmoskebabs
2018-05-13 19:10:14 I've similar problem with android app. Sending data to bluno beetle and works only with Serial Monitor connected. userHeadPic kesser