Hi,
in my hardware, the PD's Anode connect to INP1 of AFE4420, and Cathode connect to INM1, according to the description in AFE4420 datasheet, the ADC value shoud be negative:
"If connecting the positive input pin to the PD anode and negative input pin to PD cathode, then the polarity of the ADC code corresponding to the PPG signal is negative"
when I sample ambient noise, some times I got strange data like below:
there are two big data -1048575 and -2097151, could you please help me analysis the problem?
RAW HEX CODE | CONVERT DEC CODE |
000003B1 | -945 |
00000200 | -512 |
000FFFFF | -1048575 |
00FFFFFF | 1 |
00FFFFFF | 1 |
RAW HEX CODE | CONVERT DEC CODE |
0000020C | -524 |
00000400 | -1024 |
001FFFFF | -2097151 |
00FFFFFF | 1 |
00FFFFFF | 1 |
00FFFFFF | 1 |
thank you!