Make a packet with bytes and send to an external device. A device for printing using Bluetooth in iOS.

Question

I am working on printing an image using an external accessory in iOS, but I have a problem sending a request to the printer.
Here I attached an image in which the printer needs to be sent to the packet. but I don’t know how to make this package and send the package to the printer.

Answer 1

Here I attached a sample code to make a package and send it to an external device (printer) using the Objective-C language.

- (void)PrintImage:(UIImage *)image { NSMutableData* imagedata = [UIImageJPEGRepresentation(image, 0.0) mutableCopy]; NSMutableData *RequestData=[[NSMutableData alloc]init]; NSString *bitSeries = @""; NSData *data = [[NSData alloc]init]; // 1 bitSeries = @"00011011"; data=[self stringToData:bitSeries]; NSLog(@"1 : %@", data); [RequestData appendData:data]; // 2 bitSeries = @"00101010"; data=[self stringToData:bitSeries]; NSLog(@"2 : %@", data); [RequestData appendData:data]; // 3 bitSeries = @"01000011"; data=[self stringToData:bitSeries]; NSLog(@"3 : %@", data); [RequestData appendData:data]; // 4 bitSeries = @"01000001"; data=[self stringToData:bitSeries]; NSLog(@"4 : %@", data); [RequestData appendData:data]; // 5 bitSeries = @"00000000"; data=[self stringToData:bitSeries]; NSLog(@"5 : %@", data); [RequestData appendData:data]; // 6 bitSeries = @"00000000"; data=[self stringToData:bitSeries]; NSLog(@"6 : %@", data); [RequestData appendData:data]; // 7 bitSeries = @"00000000"; data=[self stringToData:bitSeries]; NSLog(@"7 : %@", data); [RequestData appendData:data]; // 8 bitSeries = @"00000000"; data=[self stringToData:bitSeries]; NSLog(@"8 : %@", data); [RequestData appendData:data]; // 9 NSMutableArray *arrstr = [self intToBinary:(int)[imagedata length]]; bitSeries = [arrstr objectAtIndex:0]; data=[self stringToData:bitSeries]; NSLog(@"9 : %@", data); [RequestData appendData:data]; bitSeries = [arrstr objectAtIndex:1]; data=[self stringToData:bitSeries]; NSLog(@"9 : %@", data); [RequestData appendData:data]; bitSeries =[arrstr objectAtIndex:2]; data=[self stringToData:bitSeries]; NSLog(@"9 : %@", data); [RequestData appendData:data]; // 10 bitSeries = @"00000001"; data=[self stringToData:bitSeries]; NSLog(@"10 : %@", data); [RequestData appendData:data]; // 11 bitSeries = @"00000000"; data=[self stringToData:bitSeries]; NSLog(@"11 : %@", data); [RequestData appendData:data]; // 12 bitSeries = @"00000000"; data=[self stringToData:bitSeries]; NSLog(@"12 : %@", data); [RequestData appendData:data]; bitSeries = @"00000000"; data=[self stringToData:bitSeries]; NSLog(@"12 : %@", data); [RequestData appendData:data]; // 13 bitSeries = @"00000000"; data=[self stringToData:bitSeries]; NSLog(@"13 : %@", data); [RequestData appendData:data]; NSLog(@"Final Data is : %@", RequestData); if (imagedata !=nil) { SessionData *obj=[SessionData sharedInstance]; obj.imageData=imagedata; obj.RequestData = RequestData; [obj setupSessionManager]; } else { [[[UIAlertView alloc]initWithTitle:@"Error" message:@"Please Select Image." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil] show]; } } -(NSData *)stringToData : (NSString *)bitSeries { uint8_t value = strtoul([bitSeries UTF8String], NULL, 2); NSLog(@"bitSeries : %@ -------> Value : %u",bitSeries, value); NSData *data = [NSData dataWithBytes:&value length:sizeof(value)]; return data; } - (NSMutableArray *)intToBinary:(int)number { int bits = sizeof(number) * 8; int bitcnt=bits; NSMutableArray *arrStr=[[NSMutableArray alloc]init]; NSMutableString *binaryStr = [NSMutableString string]; for (; bits > 0; bits--, number >>= 1) { [binaryStr insertString:((number & 1) ? @"1" : @"0") atIndex:0]; } if (bitcnt == 32) { binaryStr=[[binaryStr substringFromIndex:8] mutableCopy]; } else if(bitcnt ==16) { binaryStr = [[@"00000000" stringByAppendingString:binaryStr] mutableCopy]; } else if (bitcnt == 8) { binaryStr = [[@"0000000000000000" stringByAppendingString:binaryStr] mutableCopy]; } [arrStr addObject:[binaryStr substringToIndex:8]]; [arrStr addObject:[binaryStr substringWithRange:NSMakeRange(8, 8)]]; [arrStr addObject:[binaryStr substringFromIndex:16]]; NSLog(@"%@",arrStr); return arrStr; }