Ear-clip Heart Rate Sensor logs wrong stuff

I’m newbie and i must do something wrong with Grove - Ear-clip Heart Rate Sensor.

I tried all possible wiring combinations. Connecting sensor to 5V/GND/D2. I also tried 3.3V.

I use Arduino Uno and latest Arduino IDE.

I use code from Seeedstudio wiki page. Log shows “Heart_rate_is: 54464” or some other big number, some times it is 65535.

Below is what is logged. Thanks

Heart rate test begin.
0
5000
0
1
5010
10
2
5010
0
3
5010
0
4
5010
0
5
5010
0
6
5010
0
7
5010
0
8
5010
0
9
5010
0
10
5010
0
11
5010
0
12
5010
0
13
5010
0
14
5010
0
15
5010
0
16
5010
0
17
5010
0
18
5010
0
19
5010
0
20
5010
0
Heart_rate_is: 54464
0
5010
0
1
5010
0
2
5010
0
3
5010
0
4
5010
0
5
5010
0
6
5011
1
7
5011
0
8
5011
0
9
5011
0
10
5011
0
11
5011
0
12
5011
0
13
5011
0
14
5011
0
15
5011
0
16
5011
0
17
5011
0
18
5011
0
19
5011
0
20
5011
0
Heart_rate_is: 20352
0
5011
0