ios - ibeacons 发送 rssi 值为 0

Question

我有 8 个 iBeacon，我给了它们所有相同的 proximityUUID 和不同的主要次要值

然而，当我尝试使用手机寻找信标时，其中一些发送的“rssi”值为 0

这是为什么？

    @implementation CLBeacon(description)
-(NSString *)stringProximity{
    switch (self.proximity) {
        case CLProximityUnknown:
            return @"Unknown";
        case CLProximityImmediate:
            return @"less than 0.5 meters away";
        case CLProximityNear:
            return @"0.5<distance<4 meters away";
        case CLProximityFar:
            return @"more than 4 meters away";
    }
    return @"";
}

-(NSString *)UUIDString{
    NSMutableString *string = [[[self proximityUUID]UUIDString]mutableCopy];
    [string replaceOccurrencesOfString:@"-" withString:@"-\n" options:0 range:NSMakeRange(0, [string length])];
    return string;
}
-(NSString *)describe{
    NSString *contents = [NSString stringWithFormat:@"proximityUUID:%@\nmajor:%@\nminor:%@\naccuracy:%f\nproximity:%@\nrssi:%ld",[self UUIDString],[self major],[self minor],[self accuracy],[self stringProximity],[self rssi]];
    return contents;
}

@end

@implementation WBBeaconManager


-(id)init{
    self = [super init];
    if(self){
    self.locationManager = [[CLLocationManager alloc] init];
    self.locationManager.delegate = self;
    [self initRegion];
    [self locationManager:self.locationManager didStartMonitoringForRegion:self.beaconRegion];
    }
    return self;
}

- (void)locationManager:(CLLocationManager *)manager didStartMonitoringForRegion:(CLRegion *)region {
    [self.locationManager startRangingBeaconsInRegion:self.beaconRegion];
}

- (void)initRegion {
    NSUUID *uuid = [[NSUUID alloc] initWithUUIDString:BEACONUUID];
    self.beaconRegion = [[CLBeaconRegion alloc] initWithProximityUUID:uuid identifier:BEACONIDENTIFIER];
    [self.locationManager startMonitoringForRegion:self.beaconRegion];

}

- (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region {
    NSLog(@"Beacon Found");
    [self makeText:[NSString stringWithFormat:@"entered region:%@",region.identifier ]];
    [self.locationManager startRangingBeaconsInRegion:self.beaconRegion];
    [self makeText:[NSString stringWithFormat:@"entered region: %@",region.identifier]];
}

-(void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region {
    NSLog(@"Left Region");
    [self makeText:[NSString stringWithFormat:@"left region:%@",region.identifier ]];
    [self.locationManager stopRangingBeaconsInRegion:self.beaconRegion];
     [self makeText:[NSString stringWithFormat:@"left region: %@",region.identifier]];
//    self.beaconFoundLabel.text = @"No";
}

-(void)locationManager:(CLLocationManager *)manager didRangeBeacons:(NSArray *)beacons inRegion:(CLBeaconRegion *)region {
    CLBeacon *beacon = [beacons firstObject];
    for(CLBeacon *b in beacons){
        LogInfo(@"%@",[b describe]);
    }
//    if(beacon.proximity == CLProximityNear || beacon.proximity == CLProximityImmediate){
    [self makeText:[beacon describe]];
//    }
}

-(void)dealloc{
    [self.locationManager stopMonitoringForRegion:self.beaconRegion];
    [self.locationManager stopRangingBeaconsInRegion:self.beaconRegion];
}
@end

这是日志输出:

proximityUUID:73A7B094-35DD-4B36-A0AA-F11C62E9B4B0
major:0
minor:3
accuracy:-1.000000
proximity:Unknown
rssi:0

Answer 1

RSSI 是“接收到的信标信号强度，以分贝为单位”。有时信标监听器会找到信标，但实际上无法确定其 RSSI。这就是为什么你的准确性是负面的。 RSSI 也是“自上次向您的应用报告信标范围以来收到的样本值”的平均值。

A negative value in this property signifies that the actual accuracy could not be determined.

在这种情况下，您可能即将离开信标区域，或者您正处于其范围的边缘。