ADPD144RI - SPO2 data read EXAMPLE

asacharya

on Jul 25, 2021

Please share an example code for ADPD144RI read data from ESP32 or Arduino

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0 GlenBu

on Jul 28, 2021 8:38 PM
Hi there,

Please check the thread at the link below:

https://ez.analog.com/optical_sensing/f/q-a/165141/adpd144ri-software-code-example

Regards,

Glen B.
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0 subbu

on Aug 3, 2021 10:29 AM in reply to GlenBu

Dear Glen,

I am writing on behalf of Suresh. The github link contains drivers for ADPD10X. It does not contain specifically for ADPD144. Please let us know if there is any other location where specific files for ADPD10X is placed.

In the meantime, We have tried to test our PCB with ADPD144.

We have programmed the register Setting values as suggested in the datasheet and also in engineering Zone forum link: (https://ez.analog.com/optical_sensing/f/q-a/165141/adpd144ri-software-code-example) have been used to program.

Initially, We tried to read the reset values of each register. The values read matched with the expected values provided in Table-13 (Register Listing) of datasheet.

We are using Poling method to read the data. Although, We have used the same register values as suggested in datasheet or Forum, The data observed in the data registers 0x64 to 0x7F are 0x0000.

We also placed the finger on the ADPD1443I, the LED did not turn on also, the data registers still sshowed 0x00000

We have followed the startup sequence suggested in the datasheet. Initially, register 0x10 is written 0x0001 during writing all the registers and later after all the registers are written, register 0x10 is written 0x0002 to enter into normal operation mode.

The register values that we programmed and the values we readout are shown below.

Reg name	Register Address	Programmed Values	Read out Values
Mode	0x10	0x00000001
Mode read	0x10		0x00000001
STATUS	0x00	0x00008000
int mask	0x1	0x000000ff
int io ctl	0x2	0x00000005
fifo thresh	0x6	0x00000000
STATUS	0x00	0x0000ff60
ID	0x08		0x00000416
slot	0x11	0x000030a9
fsample	0x12	0x0000000a
led select	0x14	0x00000116
num avg	0x15	0x00000330
ach1 0ff	0x18	0x00003fff
ach2 0ff	0x19	0x00003fff
ach3 0ff	0x1a	0x00001ff0
ach4 0ff	0x1b	0x00001ff0
bch1 0ff	0x1e	0x00003fff
bch1 0ff	0x1f	0x00003fff
bch1 0ff	0x20	0x00001ff0
bch1 0ff	0x21	0x00001ff0
	0x22	0x00003000
1coarse	0x23	0x00003005
2coarse	0x24	0x00003007
ledfine	0x25	0x00000207
a_m0de	0x30	0x00000319
a_pulse	0x31	0x00000813
leddis	0x34	0x00000000
b_m0de	0x35	0x00000319
b_pulse	0x36	0x00000813
ext sync startup	0x38	0x00000000
a_afe	0x39	0x000021f3
b_afe	0x3b	0x000021f3
	0x3c	0x00003006
a_gain	0x42	0x00001c36
a_afe_con	0x43	0x0000ada5
a_gain	0x44	0x00001c36
b_afe_con	0x45	0x0000ada5
clk written	0x4b	0x00000080
clk read	0x4b		0x00000080
alk adjust	0x4d	0x0000425e
adc_tim	0x4e	0x00000040
ext sync sel	0x4f	0x00002090
cal enb	0x50	0x00000000
	0x52	0x00000040
	0x54	0x00000020
tia gain	0x55	0x00000000
	0x5a	0x00000010
dataacc_ctl	0x5f	0x00000000
dataacc_ctl	0x5f	0x00000006
mode written	0x10	0x00000002
mode read	0x10		0x00000002
SL0TA_PD1_16BIT read	0x64		0x00000000
SL0TA_PD2_16BIT read	0x65		0x00000000
SL0TA_PD3_16BIT read	0x66		0x00000000
SL0TA_PD4_16BIT read	0x67		0x00000000
SL0TB_PD1_16BIT read	0x68		0x00000000
SL0TB_PD2_16BIT read	0x69		0x00000000
SL0TB_PD3_16BIT read	0x6a		0x00000000
SL0TB_PD4_16BIT read	0x6b		0x00000000

We also have tried to verify with respect to hardware.

The 3V and 1.8V voltages are working fine.
We are using internal LEDs. Datasheet mentions that the voltage appears on LEDX1 and LEDX2 Pin. The voltage we have observed was LEDX1=1.68V and LEDX2=2V.
The Value of capacitor used on CVLED is 1uF. The current setting of LED1 (Register 0x23) is 100mA and LED2 (Register 0x24) is 130mA, LED Pulse Width is 3uSec. Can you confirm if the example formula in Page 19 of datasheet is correct. The minimum LED voltage is considered as 4V in the equation however, minimum LED voltage is 3V.
The value of capacitor used on CVREF is 1uF. The Voltage measured on Cvref is 0V.

The schematic we have used is shown below.

Please let us know if you see any issues. We are unable to get any data (The data registers are reading 0x0000) and LED is also not turning ON when we keep the finger.

Thanks

0 GlenBu

on Aug 4, 2021 1:26 PM in reply to subbu
Hi there,

The ADPD144RI has ADPD103 and LEDs and PDs inside. So the driver for ADPD10x is the right one for ADPD144RI. You can always refer to the ADPD103 datasheet for details of the register map. The formula for CVLED calculation is correct. The 1u + 0.1u caps are OK for VLED. The 1u cap for VREF is also fine.

With regard to register settings, the register 0x5F was set to 0x0006, which prevents the data update. Have you tried to read data from the FIFO? There are a few other registers with nontypical settings in your config. The configure below worked very well. Please try if it works for you.

# ADPD144RI_Config_File
# Register Value
02 0005
06 0000
11 30A9
12 000A
14 0116
15 0330
18 3FFF
19 3FFF
1A 1FF0
1B 1FF0
1E 3FFF
1F 3FFF
20 1FF0
21 1FF0
22 3000
23 3005
24 3007
25 0207
34 0000
30 0319
31 0813
35 0319
36 0813
39 21F3
3B 21F3
3C 3006
42 1C36
43 ADA5
44 1C36
45 ADA5
4E 0040
54 0020
5A 0000

Regards,

Glen B.
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0 subbu
on Aug 4, 2021 6:45 PM in reply to GlenBu
Dear Glen,

Thanks for reply, We tried to use the suggested register values and followed steps as per the start up sequence. We are able to observe the data in Registers 0x64 to 0x6b.

However, We are unable to see the LED glow. I believe this is because of the LED pulse width set to 3uSec and pulse period to 19uSec. Please correct me if this is not the correct behavior.

What is the expected voltage across Vref capacitor. When I measured It was 0V. Is this correct.

Since, We are using Internal LEDs, Datasheet mentions, We can measure the voltage LEDX1 and LED X2. The measured value on LEDX1 is 1.68V and LEDX2 is 2V. Are these values correct.

Thanks.
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0 subbu

on Aug 5, 2021 1:33 PM in reply to subbu

Fullscreen 1_data.txt Download

*******************
*** Butterfly ***
*******************
*** Ox10 mode WR                0x00000001
*** Ox2                         0x00000005
*** Ox6                         0x00000000
*** Ox11 SLOT                   0x000030a9
*** Ox12 fsample                0x0000000a
*** Ox14 led select             0x00000116
*** Ox15 num avg                0x00000330
*** Ox18 ach1 off               0x00003fff
*** Ox19 ach2 off               0x00003fff
*** Ox1a ach3 off               0x00001ff0
*** Ox1b ach4 off               0x00001ff0
*** Ox1e bch1 off               0x00003fff
*** Ox1f bch1 off               0x00003fff
*** Ox20 bch1 off               0x00001ff0
*** Ox21 bch1 off               0x00001ff0
*** Ox22                        0x00003000
*** Ox23 1coarse                0x00003005
*** Ox24 2coarse                0x00003007
*** Ox25 ledfine                0x00000207
*** Ox34 leddis                 0x00000000
*** Ox30 a_mode                 0x00000319
*** Ox31 a_pulse                0x00000813
*** Ox35 b_mode                 0x00000319
*** Ox36 b_pulse                0x00000813
*** Ox39 a_afe                  0x000021f3
*** Ox3b b_afe                  0x000021f3
*** Ox3c                        0x00003006
*** Ox42 a_gain                 0x00001c36
*** Ox43 a_afe_con              0x0000ada5
*** Ox44 a_gain                 0x00001c36
*** Ox45                        0x0000ada5
*** Ox4b                        0x0002695
*** Ox4d                        0x00004272
*** Ox4e adc_tim                0x00000040
*** Ox54                        0x00000020
*** Ox5a                        0x00000000
*** Ox10 mode written           0x00000002
 0x1 WR clear INT               0x00000006
 0x1 INTR status RD     to check RESET     0x00000006
0x0000 is written to 0x0001 to set the Slot interrupts
0x0007 written to 0002
DATA read from 0x0000 is 0x0006
Data read in the INTR Context
*** Time Slot INTR
*** Time Slot INTR
*** Ox10 mode written   0x00000002
*** Ox10 mode read                      0x00000002
Reg address is   64  and data read is         494bcc18
Reg address is   65  and data read is         11d69f9a
Reg address is   66  and data read is         a55fbc02
Reg address is   67  and data read is         ae2f8a00
Reg address is   68  and data read is         e99aa264
Reg address is   69  and data read is          216e2d3
Reg address is   6a  and data read is         de19f14b
Reg address is   6b  and data read is         35389cd4
Reg address is   64  and data read is         b5494468
Reg address is   65  and data read is         376b96fe
Reg address is   66  and data read is         b1b846e5
Reg address is   67  and data read is         247e0000
Reg address is   68  and data read is         b348b3bc
Reg address is   69  and data read is         bfc0c147
Reg address is   6a  and data read is         bea15bef
Reg address is   6b  and data read is         31258028
Reg address is   64  and data read is         387aafb8
Reg address is   65  and data read is         7f780db2
Reg address is   66  and data read is         512ba900
Reg address is   67  and data read is         f2000000
Reg address is   68  and data read is         74cc9814
Reg address is   69  and data read is         81917a3b
Reg address is   6a  and data read is         518ef713
Reg address is   6b  and data read is         b038f9fc
Reg address is   64  and data read is         d65f9160
Reg address is   65  and data read is         590b1a4d
Reg address is   66  and data read is         64ed0000
Reg address is   67  and data read is                0
Reg address is   68  and data read is         92adaf6c
Reg address is   69  and data read is         4539ddaf
Reg address is   6a  and data read is         c66852b7
Reg address is   6b  and data read is         a0df5a50

Fullscreen 2_data.txt Download

*******************
*** Butterfly ***
*******************
*** Ox10 mode WR                0x00000001
*** Ox2                         0x00000005
*** Ox6                         0x00000000
*** Ox11 SLOT                   0x000030a9
*** Ox12 fsample                0x0000000a
*** Ox14 led select             0x00000116
*** Ox15 num avg                0x00000330
*** Ox18 ach1 off               0x00003fff
*** Ox19 ach2 off               0x00003fff
*** Ox1a ach3 off               0x00001ff0
*** Ox1b ach4 off               0x00001ff0
*** Ox1e bch1 off               0x00003fff
*** Ox1f bch1 off               0x00003fff
*** Ox20 bch1 off               0x00001ff0
*** Ox21 bch1 off               0x00001ff0
*** Ox22                        0x00003000
*** Ox23 1coarse                0x00003005
*** Ox24 2coarse                0x00003007
*** Ox25 ledfine                0x00000207
*** Ox34 leddis                 0x00000000
*** Ox30 a_mode                 0x00000319
*** Ox31 a_pulse                0x00000813
*** Ox35 b_mode                 0x00000319
*** Ox36 b_pulse                0x00000813
*** Ox39 a_afe                  0x000021f3
*** Ox3b b_afe                  0x000021f3
*** Ox3c                        0x00003006
*** Ox42 a_gain                 0x00001c36
*** Ox43 a_afe_con              0x0000ada5
*** Ox44 a_gain                 0x00001c36
*** Ox45                        0x0000ada5
*** Ox4b                        0x0002695
*** Ox4d                        0x00004272
*** Ox4e adc_tim                0x00000040
*** Ox54                        0x00000020
*** Ox5a                        0x00000000
*** Ox10 mode written           0x00000002
 0x1 WR clear INT               0x00000006
 0x1 INTR status RD     to check RESET      0x00000006
0x0000 is written to 0x0001 to set the Slot interrupts
0x0007 written to 0002
DATA read from 0x0000 is 0x0006
Data read in the INTR Context
*** Time Slot INTR
*** Time Slot INTR
*** Ox10 mode written   0x00000002
*** Ox10 mode read      0x00000002
Reg address is   64  and data read is         494bcc18
Reg address is   65  and data read is         11d69f9a
Reg address is   66  and data read is         a55fbc02
Reg address is   67  and data read is         ae2f8a00
Reg address is   68  and data read is         e99aa264
Reg address is   69  and data read is          216e2d3
Reg address is   6a  and data read is         de19f14b
Reg address is   6b  and data read is         35389cd4
Reg address is   64  and data read is         b5494468
Reg address is   65  and data read is         376b96fe
Reg address is   66  and data read is         b1b846e5
Reg address is   67  and data read is         247e0000
Reg address is   68  and data read is         b348b3bc
Reg address is   69  and data read is         bfc0c147
Reg address is   6a  and data read is         bea15bef
Reg address is   6b  and data read is         31258028
Reg address is   64  and data read is         387aafb8
Reg address is   65  and data read is         7f780db2
Reg address is   66  and data read is         512ba900
Reg address is   67  and data read is         f2000000
Reg address is   68  and data read is         74cc9814
Reg address is   69  and data read is         81917a3b
Reg address is   6a  and data read is         518ef713
Reg address is   6b  and data read is         b038f9fc
Reg address is   64  and data read is         d65f9160
Reg address is   65  and data read is         590b1a4d
Reg address is   66  and data read is         64ed0000
Reg address is   67  and data read is                0
Reg address is   68  and data read is         92adaf6c
Reg address is   69  and data read is         4539ddaf
Reg address is   6a  and data read is         c66852b7
Reg address is   6b  and data read is         a0df5a50

Dear Glen,

We are facing issue with resetting the FIFO contents. When we try to capture data multiple times, We found that, the data in FIFO was not getting updated. Please find the attached Text files 1_Data.txt and 2_DATA.txt. You can see that, data in the data FIFO is the same in both iterations.

Hence, We tried to reset the FIFO based on the steps mentioned in the Startup sequence section.

We have written a application code, to perform read operation for 4 times in a loop. After each read operation, The FIFO is reset and when read operation is performed again in loop the FIFO is resetting properly and new data is getting updated in the FIFO.

However, If We reset the board and then perform the read operation, We are observing the Previously captured data (that was observed before resetting board) is read in the data registers.

Request you to let us know if you see any mistake we are doing.

Please find the snippet below containing data that is read and register settings we are using to clear the FIFO after each read. We have followed the steps provided in startup sequence to clear the FIFO.

// Read Data

Reg address is 64 and data read is 3eb06a70

Reg address is 65 and data read is 550eb103
Reg address is 66 and data read is 5c826063
Reg address is 67 and data read is 6d56737a
Reg address is 68 and data read is 2f5a6f0e
Reg address is 69 and data read is 4b0ecc49
Reg address is 6a and data read is 1015131
Reg address is 6b and data read is 3215bf30
//Clear the FIFO
*** 0x00 0x000000ff
*** 0x5f 0x0001
*** 0x00 0x000080ff
*** 0x5f 0x00000000
*** 0x10 0x00000002
//FIFO cleared
*** 0x64 SLOTA_PD1_16BIT read *******0x00000000***
*** 0x65 SLOTA_PD2_16BIT read *******0x00000000***
*** 0x66 SLOTA_PD3_16BIT read *******0x00000000***

*** 0x67 SLOTA_PD4_16BIT read *******0x00000000***
*** 0x68 SLOTB_PD1_16BIT read *******0x00000000***
*** 0x69 SLOTB_PD2_16BIT read *******0x00000000***
*** 0x6a SLOTB_PD3_16BIT read *******0x00000000***
*** 0x6b SLOTB_PD4_16BIT read *******0x00000000***

0 GlenBu

on Aug 5, 2021 3:40 PM in reply to subbu
Hi there,

The Vref should be at 1.265V. The voltages at LEDX1 and LEDX2 looked fine , meaning there is voltage drops across the integrated red and IR LEDs.

Were you able to see the red LED glowing with the config I posted?

With regard to the FIFO read, I will ask our firmware colleague to comment.

Regards,

Glen
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0 subbu
on Aug 5, 2021 10:36 PM in reply to GlenBu
Dear Glen,

The Red led did not glow after we loaded the configuration.

What is the reason for voltage drop across LEDS.
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0 ADIApproved

on Aug 6, 2021 8:38 AM in reply to subbu
Hi Subbu,

Regarding FIFO read data can you share your code snippet to go through it.

Are you using AdpdDrvReadFifoData() API to readout data from FIFO?

Regards,

Sathishkumar
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0 GlenBu

on Aug 6, 2021 8:58 AM in reply to subbu
Hi there,

Did you set register 0x10 to 0x0002 after you loaded the config to start the data acquisition? The LEDs glow only when the ADPD144RI is in sample mode.

When LEDX1/LEDX2 are on, there is forward voltage across the LED(s), depending on the current. Please note that the LEDX1 and LEDX2 are current sink and only turned on during the LED pulses. The voltage at the LEDX1 and LEDX2 pins should be close to VLED when the LEDX1/LEDX2 are off.

Regards,

Glen B.
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0 GlenBu

on Aug 6, 2021 8:58 AM in reply to subbu
Hi there,

Did you set register 0x10 to 0x0002 after you loaded the config to start the data acquisition? The LEDs glow only when the ADPD144RI is in sample mode.

When LEDX1/LEDX2 are on, there is forward voltage across the LED(s), depending on the current. Please note that the LEDX1 and LEDX2 are current sink and only turned on during the LED pulses. The voltage at the LEDX1 and LEDX2 pins should be close to VLED when the LEDX1/LEDX2 are off.

Regards,

Glen B.
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0 subbu
on Aug 11, 2021 3:36 PM in reply to GlenBu
Dear Glen,

Yes, We have set the register 0x10 to 0x0002 after the configuration is loaded. Although, We have done this, the LEDs are not glowing. I have measured the 3V, 1.8V supplies, They are fine.

Can you share the sample data that is expected when We load the suggested configuration both in open condition and when finger is placed over the device.

What is the maximum value of pulse width that we can set..?
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ADPD144RI - SPO2 data read EXAMPLE