I'm using an arduino to read data from ADPD4101 via I2C, I'm able to toggle the LEd's increase and decrese brightness but unable to read PPG from IN1 which connected to a PD and PD connected to VC1
#include <Wire.h>
#define ADPD_ADDR 0x24
// System registers
#define REG_SYS_CTL 0x000F
#define REG_SW_RESET 0x8000 // bit15 = SW_RESET
#define REG_OSC_1M_EN 0x0002 // bit1 = 1 MHz oscillator enable
#define REG_AFE_EN 0x0001 // bit0 = AFE state‑machine enable
// Pattern/timing registers
#define REG_OPMODE 0x0010
#define REG_LED_POW12_A 0x0105 // Red LED Verified
#define REG_LED_POW34_A 0x0106 // Green LED Verified
#define REG_COUNTS_A 0x0107
#define REG_PERIOD_A 0x0108
#define REG_LED_PULSE_A 0x0109 // Brightness verified
#define REG_PATTERN_A 0x010D
// PD1 registers
#define REG_INPUT_A 0x0100
#define REG_SLOT_EN 0x0110 // FULL Data Format Register
#define REG_FIFO_COUNT 0x0006
#define REG_FIFO_DATA 0x0005
// Chip ID
#define REG_CHIP_ID 0x0008
// Sampling Frequency
#define TS_FREQ_H 0x000E
#define TS_FREQ_L 0x000D
#define REG_FIFO_COUNT 0x0006
#define REG_FIFO_DATA 0x002F
void setup() {
Serial.begin(115200);
Wire.begin();
delay(100);
writeReg(0x0009, 0x0080); //0009 0080 # 32MHz trim - trim your own clock
writeReg(0x000B, 0x02B2); //000B 02B2 # 1MHz trim - trim your own clock
writeReg(0x000C, 0x0012); //000C 0012 # 32kHz trim - trim your own clock
writeReg(0x000D, 0x2710); //000D 2710 # 100 Hz
writeReg(0x000F, 0x0006); //000F 0006 # enable 1MHz osc
writeReg(0x0020, 0x0004); //0020 0004 # in1 connected to vc1 during sleep, everything else floating
writeReg(0x0021, 0x0000); //0021 0000 # all inputs single ended, vc1 set to Vdd during sleep
writeReg(0x0022, 0x0003); //0022 0003 # gpio0 is output, inverted
writeReg(0x0023, 0x0002); //0023 0002 # intx to gpio0
writeReg(0x0014, 0x8000); //0014 8000 # fifo thresh interrupt to intx
writeReg(0x0006, 0x00FF); //0006 00FF # fifo threshold 128 bytes
//## timeslot A - continuous connect mode
//
writeReg(0x0100, 0x0000);//0100 0000 # Rin = 500, tsA offset = 0, skip subsample
writeReg(0x0101, 0x40DA);//0101 40DA # path = TIA + BPF + INT + ADC
writeReg(0x0102, 0x0001);//0102 0001 # IN1 to channel 1, others disconnected
writeReg(0x0103, 0x5002);//0103 5002 # precondition inputs to TIA_Vref, VC1 active state = V_delta
writeReg(0x0104, 0x03C0);//0104 03C0 # Rf = 200k Rint = 400k
writeReg(0x0105, 0x0017);//0105 0017 # 38 mA on LED1A
writeReg(0x0106, 0x0000);//0106 0000
writeReg(0x0107, 0x0104);//0107 0104 # 4 pulses
writeReg(0x0108, 0x0000);//0108 0000 # period set by automatic period of continuous connect mode
writeReg(0x0109, 0x0610);//0109 0210 # led width= 2us led offset=16 us
writeReg(0x010A, 0x0003);//010A 0003 # integrator width=3 us
writeReg(0x010B, 0x0210);//010B 0210 # integrator offset=16.5 us - ADJUST FINE OFFSET
writeReg(0x010C, 0x010C);//010C 0001 # no modulation
writeReg(0x0110, 0x0003);//0110 0003 # signal size = 3 bytes
writeReg(0x011D, 0x0099);//010D 0099 # -++- int pattern
writeReg(0x011E, 0x0000);//010E 0000 # NO OFFSET - review if needed
writeReg(0x011F, 0x0000);//010F 0000 # NO OFFSET - review if needed
writeReg(0x0112, 0x0000);//0112 0000 # no decimation
// 3) TIA Gain set to 500kΩ
uint16_t val_04 = readReg(0x0104);
val_04 &= ~0x0003;
val_04 |= 0x0001; // 0b01 = 500 kΩ gain
writeReg(0x0104, 0x0300); //TIME SLOT A
//writeReg(REG_LED_POW12_A, 0x0A00); // LED1A & LED2A RED and IR LED SLOT A
//writeReg(0x0125, 0x0A0A); // SLOT B RED IR
writeReg(REG_LED_POW34_A, 0x0005); // Greeen LED SLOT A
//writeReg(0x0126, 0x000A); // Green LED SLOT B
Serial.println("LED currents x mA");
writeReg(0x00B0, 0x0010); // By fourm
uint16_t Imp_status = readReg(0x00B0);
Serial.print("Status of IMP byte "); Serial.println(Imp_status);
writeReg(0x0010, 0x0001); // OPMODE: Enable Slot A only
}
void loop() {
uint16_t Full_signal = readReg(0x002F); // bits [15:0]
//uint16_t status_fifo = readReg(0x0000);
//// Check for overflow or underflow
//if (status_fifo & (1 << 13) || status_fifo & (1 << 14)) {
// writeReg(0x0000, (1 << 15)); // CLEAR_FIFO = 1
//}
uint16_t low = readReg(0x0030); // bits [15:0]
uint16_t high = readReg(0x0031) ; // bits [23:16] only
uint16_t low_B = readReg(0x0038); // bits [15:0]
uint16_t high_B = readReg(0x0039) ; // bits [23:16] only
uint32_t sample_B = ((uint32_t)high_B << 16) | low_B;
uint8_t dark_high = readReg(0x0035);
uint8_t dark_low = readReg(0x0034);
uint32_t sample_dark = ((uint32_t)dark_high << 16) | dark_low;
uint32_t sample = ((uint32_t)high << 16) | low;
uint32_t PPG = sample - sample_dark;
//Serial.print(Full_signal);Serial.println(",");
uint16_t Imp_status = readReg(0x00B0);
Serial.print("Status of IMP byte "); Serial.println(Imp_status);
//Serial.print(high); Serial.print(","); Serial.print(low);Serial.print(",");
//Serial.print(dark_high); Serial.print(","); Serial.println(dark_low);
//Serial.println(sample);
delay(10);
} here is my arduino code, readReg and writeReg are functions to read or write data from a specific register of ADPD4101 and I read 16 as the output for reading 0x00B0. Please help
I'm using reflective PPG setup where my PD's and LED are on the same surface
