我正在尝试从BLE设备读取数据，从委托方法获取数据
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error。
我正在使用属性value从CBCharacteristic对象中读取数据。
这将返回NSData。
我将此NSData转换为字节。
如何根据此字节数据计算权重？通过这段代码，我得不到确切的价值。
这是MyCode
/** This callback lets us know more data has arrived via notification on the characteristic
*/
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
{
NSLog(@"peripheral %@", peripheral);
NSLog(@"chacteristic %@", characteristic);
NSLog(@"chacteristic value %@", [characteristic value]);
Response Is Like This
peripheral <CBPeripheral: 0x15e469e90, identifier = A4B7E3A0-A988-02CF-3FAE-3B62056F465B, name = eBody-Fat-Scale, state = connected>
chacteristic <CBCharacteristic: 0x15e250980, UUID = 2A9D, properties = 0x20, value = <0ee803df 07010116 390901ff ff0000>, notifying = YES>
chacteristic value <0ee803df 07010116 390901ff ff0000>
if (error) {
NSLog(@"Error discovering characteristics: %@ and %@", [error localizedDescription],[error localizedFailureReason]);
return;
}
int height;
self.targetPeripheral = peripheral;
NSData *tempData=characteristic.value;
NSString *stringFromData = [[NSString alloc] initWithData:characteristic.value encoding:NSUTF8StringEncoding];
NSString *str = [NSString stringWithUTF8String:[tempData bytes]];
NSLog(@"string data %@",str);
NSData *lol = characteristic.value;
NSLog(@"length %lu", (unsigned long)[lol length]);
Byte *byte = (Byte *)[lol bytes];
for(int i = 0;i<[lol length];i++)
{
NSLog(@"Receive byte：%d",byte[i]);
}
/* self.targetPeripheral = peripheral;
NSString *stringFromData = [[NSString alloc] initWithData:characteristic.value encoding:NSUTF8StringEncoding];
NSData *lol = characteristic.value;
Byte *byte = (Byte *)[lol bytes];
for(int i = 0;i<[lol length];i++)
{
NSLog(@"Received bytes：%d",byte[i]);
}*/
if(byte[0] == 0xfc)
{
Byte weightHigh = 0;
if(byte[1] >= 0xc0)
{
weightHigh = byte[1] - 0xc0;
}
else if(byte[1] >= 0x80)
{
weightHigh = byte[1] - 0x80;
}
else if(byte[1]>= 0x40)
{
weightHigh = byte[1] - 0x40;
}
float weightdata = (float)(weightHigh * 256 + byte[2])/10;
NSUserDefaults *prefers = [NSUserDefaults standardUserDefaults];
if([[prefers objectForKey:@"units"] isEqualToString:@"ft"])
{
NSString *weight = [[NSString alloc]initWithFormat:@"%.1f",[UnitParse convertKgToLb:weightdata]];
_weightDataLabel.text = [[NSString alloc] initWithFormat:@"%@",weight];
}
else
{
NSString *weight = [[NSString alloc]initWithFormat:@"%.1f",weightdata];
_weightDataLabel.text = [[NSString alloc] initWithFormat:@"%@",weight];
}
if(weightdata != _lastWeightData)
{
[RCCircleAnimation stopAnimation:_circleImageView.layer];
_lastWeightData = weightdata;
if(weightHigh * 256 + byte[2] == 0x3f*256+255)//overload
{
_weightDataLabel.text = @"overload";
}
else
{
NSThread* myThread1 = [[NSThread alloc] initWithTarget:self selector:@selector(mySoundPlayer)object:nil];
[myThread1 start];
NSMutableDictionary *dic = [[NSMutableDictionary alloc]init];
[dic setObject:[[NSString alloc] initWithFormat:@"%2f",weightdata] forKey:@"Weight"];
NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSString *datestr = [formatter stringFromDate:[NSDate date]];
[dic setObject:datestr forKey:@"TestTime"];
/* // First Time
NSUserDefaults *userDefaults ;
userDefaults = [NSUserDefaults standardUserDefaults];
if ([userDefaults objectForKey:@"UserWeightDataArray"] == nil)
{
[_valuesArray addObject:dic];
[userDefaults setObject:_valuesArray forKey:@"UserWeightDataArray"];
[userDefaults synchronize];
}
else
{
// second Time
[_dateArray addObject:dic];
_finalArray = [[_dateArray arrayByAddingObjectsFromArray:[[NSUserDefaults standardUserDefaults] objectForKey:@"UserWeightDataArray"]] mutableCopy];
[userDefaults setObject:_finalArray forKey:@"UserWeightDataArray"];
[userDefaults synchronize];
}
*/
height = [[[MySingleton sharedSingleton].nowuserinfo valueForKey:@"Height"] intValue];
float bmi = weightdata/((height/100.0f)*(height/100.0f));
_bmiDataLabel.text = [[NSString alloc] initWithFormat:@"%.1f",bmi];
NSLog(@"_weightDataLabel.text %@", _weightDataLabel.text);
[self uploadDeviceInformationToServer:height weight:[[NSString alloc]initWithFormat:@"%.1f",weightdata]];
NSThread* myThread2 = [[NSThread alloc] initWithTarget:self selector:@selector(uploadWeightData:)object:dic];
[myThread2 start];
NSThread* myThread3 = [[NSThread alloc] initWithTarget:self selector:@selector(getAdviceByWeightData:)object:dic];
[myThread3 start];
NSThread* myThread = [[NSThread alloc] initWithTarget:self selector:@selector(sendCloseCmd)object:nil];
[myThread start];
}
}
}
else
{
_lastWeightData = 0;
Byte weightHigh = 0;
if(byte[1] >= 0xc0)
{
weightHigh = byte[1] - 0xc0;
}
else if(byte[1] >= 0x80)
{
weightHigh = byte[1] - 0x80;
}
else if(byte[1]>= 0x40)
{
weightHigh = byte[1] - 0x40;
}
float weightdata = (float)(weightHigh * 256 + byte[2])/10;
NSUserDefaults *prefers = [NSUserDefaults standardUserDefaults];
NSLog(@"data is %@",[prefers objectForKey:@"units"]);
if([[prefers objectForKey:@"units"] isEqualToString:@"ft"])
{
double temp=[UnitParse convertKgToLb:weightdata];
double temp1=[UnitParse convertLbToKg:weightdata];
NSString *weight = [[NSString alloc]initWithFormat:@"%.1f",temp];
NSLog(@"weight in if .... %@ and lb is %.1f and kg %.1f",weight,temp,temp1);
_weightDataLabel.text = [[NSString alloc] initWithFormat:@"%@",weight];
}
else
{
double temp=[UnitParse convertKgToLb:weightdata];
double temp1=[UnitParse convertLbToKg:weightdata];
NSLog(@"weight in if .... %f and lb is %.1f and kg %.1f",weightdata,temp,temp1);
NSString *weight = [[NSString alloc]initWithFormat:@"%.1f",temp1];
NSLog(@"weight in else .... %@",weight);
_weightDataLabel.text = [[NSString alloc] initWithFormat:@"%@",weight];
}
// NSString *weight = [[NSString alloc]initWithFormat:@"%.1f",[UnitParse convertKgToLb:weightdata]];
// _weightDataLabel.text = [[NSString alloc] initWithFormat:@"%@",weight];
}
// Have we got everything we need?
if ([stringFromData isEqualToString:@"EOM"]) {
// We have, so show the data,
//[self.textview setText:[[NSString alloc] initWithData:self.data encoding:NSUTF8StringEncoding]];
NSLog(@"GetDataValue : %@",[[NSString alloc] initWithData:self.data encoding:NSUTF8StringEncoding]);
// Cancel our subscription to the characteristic
[peripheral setNotifyValue:NO forCharacteristic:characteristic];
// and disconnect from the peripehral
[self.centralManager cancelPeripheralConnection:peripheral];
}
}
字节数据的输出是：
Receive byte：14 byte data is 0xe
Receive byte：176 byte data is 0xb0
Receive byte：4 byte data is 0x4
Receive byte：223 byte data is 0xdf
Receive byte：7 byte data is 0x7
Receive byte：1 byte data is 0x1
Receive byte：1 byte data is 0x1
Receive byte：23 byte data is 0x17
Receive byte：48 byte data is 0x30
Receive byte：17 byte data is 0x11
Receive byte：1 byte data is 0x1
答案 0 :(得分：1)
使用此代码读取重量或心率或温度的字节数据。
Lol is the nsdata object.
const uint8_t *reportData = [lol bytes];
uint16_t bpm = (uint16_t)reportData;
CGFloat weightdata = 0;
if ((reportData[1] & 0x01) == 0)
{
/* uint8 bpm */
NSLog(@"if reportData is %d",reportData[1]);
bpm = CFSwapInt16LittleToHost(*(uint16_t *)(&reportData[1]));
NSLog(@"if bpm data is %d",bpm);
weightdata = bpm/200.0;
}
else
{
/* uint16 bpm */
NSLog(@"reportData is %d",reportData[1]);
bpm = CFSwapInt16LittleToHost(*(uint16_t *)(&reportData[1]));
NSLog(@"bpm data is %d",bpm);
weightdata = bpm/200.0;
}