Okay, so I've looked through a thousand tutorials and other Stack Overflow threads (so please don't list as duplicate without answering the question) and I cannot work out how to use this functionality.
I have followed this tutorial:
http://code.tutsplus.com/tutorials/ios-7-sdk-core-bluetooth-practical-lesson--mobile-20741
I have a system where a central can connect to a peripheral and read a characteristic from it.
I am now trying to get my central to rewrite the data within the characteristic but am finding the write line that I have called just being ignored.
I have declared my characteristic within my peripheral class as such:
self.transferCharacteristic = [[CBMutableCharacteristic alloc] initWithType:[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID] properties:CBCharacteristicPropertyNotify|CBCharacteristicPropertyWriteWithoutResponse|CBCharacteristicPropertyRead value:nil permissions:CBAttributePermissionsReadable|CBAttributePermissionsWriteable];
And in my centralManager I have called
[peripheral writeValue:[@"rewritten!" dataUsingEncoding:NSUTF8StringEncoding] forCharacteristic:characteristic type:CBCharacteristicWriteWithoutResponse];
But the line is ignored. Can anyone talk me through what might be wrong? Do I need to add a method to my peripheral class?
Also, I've tried doing it WithResponse but it still doesn't even call that method from the peripheral either.
Are you still stuck with the problem?
I guess your problem is persisting due to the fact that you have not implemented didReceiveWriteRequests
method.
// Processes write command received from a central.
- (void)peripheralManager:(CBPeripheralManager *)peripheral didReceiveWriteRequests:(NSArray *)requests
{
CBATTRequest *request = [requests objectAtIndex:0];
NSData *request_data = request.value;
CBCharacteristic *write_char = request.characteristic;
//CBCentral* write_central = request.central;
//NSUInteger multi_message_offset = request.offset;
// Face commands this PWR RX to advertise serno UUID?
int total_write_requests = 0;
if ([ write_char.UUID isEqual:[CBUUID UUIDWithString:YOUR_CHARACTERISTIC_UUID]] )
{
// Read desired new_state data from central:
unsigned char *new_state = (unsigned char *)[request_data bytes];
my_new_state = new_state[0];
#endif
NSLog(@"- advertise serno UUID: %s", my_new_state ? "TRUE" : "FALSE" );
// Select UUID that includes serno of PWR RX, for advertisements:
++total_write_requests;
}
if ( total_write_requests )
{
[peripheral respondToRequest:request withResult:CBATTErrorSuccess]; // result = success
}
else
{
NSLog(@"_no_write_request_FAULT !!");
}
}
Comment out the [peripheral respondToRequest:request withResult:CBATTErrorSuccess];
, as in your case you are using CBCharacteristicWriteWithoutResponse.
Code taken from: where is example of iOS Bluetooth LE peripheralManager didReceiveWriteRequests