Accessing user defined delegate via multiple ViewControllers - iOS - ios

Question

I'm using the BLE framework files that came with some hardware, but I'm only able to call the functions in my first view controller. My application has two view controllers and it is my intention to write and read BLE data in both views, using the BLEDelegate.
Everything works as expected in the first view controller, but I get no action from the BLE files in the second view controller.
This is a skeleton of my project.
BLE.h
#import <CoreBluetooth/CoreBluetooth.h>
#protocol BLEDelegate
#optional
-(void) bleDidReceiveData:(unsigned char *) data length:(int) length;
#required
#end
#interface BLE : NSObject;
#property (nonatomic,assign) id <BLEDelegate> delegate;
-(void) write:(NSData *)d;
#end
BLE.m
#import "BLE.h"
#interface BLE ()
#end
#implementation BLE
#synthesize delegate;
-(void) write:(NSData *)d
{
//send BLE packet
NSData *data = [NSData dataWithBytes: &d length: sizeof(d)];
NSLog(#"%#", data);
}
#end
ViewController.h
#import <UIKit/UIKit.h>
#import "BLE.h"
#interface ViewController : UIViewController<BLEDelegate>
#property (nonatomic, strong) BLE *ble;
#property (weak, nonatomic) IBOutlet UIButton *btnClicked;
#end
ViewController.m
#import "ViewController.h"
#import "SecondViewController.h"
#interface ViewController ()
#end
#implementation ViewController
#synthesize ble;
- (void)viewDidLoad {
[super viewDidLoad];
ble = [[BLE alloc] init];
ble.delegate = self;
}
-(void)bleDidReceiveData:(unsigned char *)data length:(int)length
{
//parse data
}
- (IBAction)btnClicked:(id)sender
{
uint32_t packet = 0xFFFF;
NSData *data = [NSData dataWithBytes: &packet length: sizeof(packet)];
[ble write:data];
}
#end
SecondViewController.h
#import <UIKit/UIKit.h>
#import "BLE.h"
#interface SecondViewController : UIViewController<BLEDelegate>
#property (nonatomic, strong) BLE *ble;
#property (weak, nonatomic) IBOutlet UIButton *btnClicked;
#end
SecondViewController.m
#import "SecondViewController.h"
#import "ViewController.h"
#interface SecondViewController ()
#end
#implementation SecondViewController
#synthesize ble;
- (void)viewDidLoad {
[super viewDidLoad];
ble = [[BLE alloc] init];
ble.delegate = self;
}
-(void)bleDidReceiveData:(unsigned char *)data length:(int)length
{
//parse data
}
- (IBAction)btnClicked:(id)sender
{
uint32_t packet = 0xFFFF;
NSData *data = [NSData dataWithBytes: &packet length: sizeof(packet)];
[ble write:data];
}
#end