getting data from one view controller to another - ios

Question

I am getting the battery level of my bluetooth le device (batteryLevel) which is a float in one view. I want to pass it to another view to display it in a textfield.
code in view one
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:
(CBCharacteristic *)characteristic error:(NSError *)error
{[self.testPeripheral readValueForCharacteristic:mycharacteristic];
char batlevel;
[characteristic.value getBytes:&batlevel length:1];
self.batteryLevel = (float)batlevel;
NSLog(#"level;%f",batteryLevel);}
this gives me a value like 80.00000
I want to put this into another view to display.
I have tried in view2.h file I have placed
view1 *t
and then
- (void) batteryIndicatorTimer:(NSTimer *)timer {
TIBLEUIBatteryBar.progress = t.batteryLevel / 100;
[t readBattery:[t testPeripheral]]; // Read battery value of keyfob again
NSLog(#"t.batterylevel:%f",t.batteryLevel);
}
but I don't get a value for t.batteryLevel
what am I doing wrong and how can I do this?

Answer 1

There's a myriad number of ways to accomplish this using delegates or assigning properties in presentingViewControllers/destinationViewControllers, but since I don't know your app flow I'll give you a way that should work with whatever setup you have. Just update batteryLevel in your viewController that is the peripheralDelegate then simply save the value to the NSUserDefaults:
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:
(CBCharacteristic *)characteristic error:(NSError *)error
{
//Grab your battery value and store in float
//Then just save to defaults so you can access wherever.. Keep overwriting this value each time you update
[[NSUserDefaults standardUserDefaults]setFloat:batteryVal forKey:#"battery_level"];
}
And then inside your other viewController just assign the value inside viewWillAppear or something.
-(void)viewWillAppear:(BOOL)animated
{
float batteryLevel = [[NSUserDefaults standardUserDefaults]floatForKey:#"battery_level"];
self.yourTextField.text = [NSString stringWithFormat:#"%f",batteryLevel];
}