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AFE4900: AFE4900 PPG+ECG

Prodigy 10 points

Replies: 1

Views: 171

Part Number: AFE4900

Hi,

I'm trying to use AFE4900 Develop a 3 PPG + ECG device, and I have two issue need help.

1. I can't get the ECG signal. 

I can see the different by raw data when I put on or take off my finge , but It just no ECG signal (whether Gain =12 or Gain=2).

2. The PPG raw data MSB always the same value(like 0x0A or 0x0D).

I'm using internal oscillator then division ratio to 32KHz and  set PRF to  250Hz, no FIFO.

Here is my AFE4900 setting :

{0x00, 0x000020}, /*CONTROL0*/
{0x01, 0x000013},/*LED2STC*/
{0x02, 0x000014}, /*LED2ENDC*/
{0x03, 0x000019},/*LED1LEDSTC*/
{0x04, 0x00001C}, /*LED1LEDENDC*/
{0x05, 0x000017},/*ALED2STC*/
{0x06, 0x000018}, /*ALED2ENDC*/
{0x07, 0x00001B}, /*LED1STC*/
{0x08, 0x00001C},/*LED1ENDC*/
{0x09, 0x000011}, /*LED2LEDSTC*/
{0x0A, 0x000014},/*LED2LEDENDC*/
{0x0B, 0x00001F}, /*ALED1STC*/
{0x0C, 0x000020},/*ALED1ENDC*/
{0x0D, 0x000015},/*LED2CONVST*/
{0x0E, 0x000017},/*LED2CONVEND*/
{0x0F, 0x000019},/*ALED2CONVST*/
{0x10, 0x00001B},/*ALED2CONVEND*/
{0x11, 0x00001D}, /*LED1CONVST*/
{0x12, 0x00001F}, /*LED1CONVEND*/
{0x13, 0x000021}, /*ALED1CONVST*/
{0x14, 0x000022}, /*ALED1CONVEND*/
{0x1D, 0x000080}, /*PRPCOUNT*/ 
{0x1E, 0x000000}, /*CONTROL1*/
{0x1F, 0x000D0D}, /*TIAGAIN_2_3*/ 
{0x20, 0x008015}, /*TIAGAIN*/ 
{0x21, 0x005001}, /*TIA_AMB_GAIN*/ 
{0x22, 0xF59659}, /*LEDCNTRL1*/ 
{0x23, 0x12C218}, /*CONTROL2*/
{0x24, 0x000000},/*LEDCNTRL2*/
{0x29, 0x000000}, /*CLKDIV1*/
{0x31, 0x000020}, /*CONTROL3*/
{0x34, 0x000000}, /*PROG_INT2_STC*/
{0x35, 0x000000}, /*PROG_INT2_ENDC*/
{0x36, 0x000015},/*LED3LEDSTC*/
{0x37, 0x000018},/*LED3LEDENDC*/
{0x39, 0x000005}, /*CLKDIV2*/
{0x3A, 0x194214}, /*OFFDAC*/ 
{0x3B, 0x000000}, /*THRDETLOW*/
{0x3C, 0x000000}, /*THRDETHIGH*/
{0x3D, 0x000000}, /*THRDET*/
{0x3E, 0x0008C1}, /*I_OFFDAC*/ 
{0x42, 0x000000}, /*FIFO*/
{0x43, 0x00001D}, /*LED4LEDSTC*/
{0x44, 0x000020}, /*LED4LEDENDC*/
{0x45, 0x000000}, /*TG_PD1STC*/
{0x46, 0x000000}, /*TG_PD1ENDC*/
{0x47, 0x000000}, /*TG_PD2STC*/
{0x48, 0x000000}, /*TG_PD2ENDC*/
{0x49, 0x000000}, /*TG_PD3STC*/
{0x4A, 0x000000}, /*TG_PD3ENDC*/
{0x4B, 0x000000}, /*CONTROL4*/
{0x4E, 0x000004}, /*DUAL_PD*/
{0x50, 0x180008}, /*CONTROL5*/
{0x51, 0x000000}, /*FIFO_OFFSET*/
{0x52, 0x000028}, /*DATA_RDY_STC*/
{0x53, 0x000028},/*DATA_RDY_ENDC*/
{0x54, 0x000000}, /*MASK_PPG*/
{0x57, 0x000000}, /*PROG_INT1_STC*/
{0x58, 0x000000}, /*PROG_INT1_ENDC*/
{0x61, 0x000000},/*ECG_CHOP*/
{0x62, 0x800000},/*ECG_RLD*/
{0x64, 0x000007}, /*DYN_TIA_STC*/
{0x65, 0x00002A}, /*DYN_TIA_ENDC*/
{0x66, 0x000007},/*DYN_ADC_STC*/
{0x67, 0x00002A},/*DYN_ADC_ENDC*/
{0x68, 0x000007},/*DYN_CLOCK_STC*/
{0x69, 0x00002A},/*DYN_CLOCK_ENDC*/
{0x6A, 0x00002E},/*DEEP_SLEEP_STC*/
{0x6B, 0x000080}, /*DEEP_SLEEP_ENDC*/
{0x6C, 0x000000}, /*PD_SHORT*/
{0x72, 0x000008}, /*LED_DRIVER_CONTROL*/
{0x73, 0x000000}, /*THR_DETECT_LOGIC*/

And this is how I get data:

Buff_ptr[ADC_DataCnt] = SPI_READfromAFE(0x2A) & 0x1FFFFF;       // Read register 0x2A from AFE     
Buff_ptr[ADC_DataCnt + 1] = SPI_READfromAFE(0x2B) & 0x1FFFFF; //Read register 0x2B from AFE   
Buff_ptr[ADC_DataCnt + 2] = SPI_READfromAFE(0x2C) & 0x1FFFFF; //Read register 0x2C from AFE   
Buff_ptr[ADC_DataCnt + 3] = SPI_READfromAFE(0x2D) & 0x1FFFFF; //Read register 0x2D from AFE   

ADC_DataCnt += 4;

Thanks.

  • Hello Walter,

    Welcome to TI E2E forum!

    We would like to take this discussion offline since the device AFE4900 is under selective disclosure.
    Can you send your questions to biosensing_afe-support@list.ti.com along with a reference to this E2E post?

    Regards

    Praveen

    TI makes no warranties and assumes no liability for applications assistance or customer product design. You are fully responsible for all design decisions and engineering with regard to your products, including decisions relating to application of TI products. By providing technical information, TI does not intend to offer or provide engineering services or advice concerning your designs.

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