• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 46 subscribers
  • Views 677 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ADS1292ECG-FE： Problem debugging the communication of ADS1292

jszhang
Prodigy 160 points
Part Number: ADS1292ECG-FE
Other Parts Discussed in Thread: ADS1292

Hi everyone,

I purchased an ADS1292 ECG evm board for debugging.  Our development platform is NXP RT1050. Because ourselves hardware is not ready yet, I used a RT1050 EVM board to connect the ADS 1292 on the 

ADS1292 ECG evm board. 

The connection is like this: disconnect these ADS1292 pin from the MSP430:  DRDY, DOUT, SCLK, DIN, CS,  START, PWDN/RESET.  Connect these pin to the RT1050 EVM board. Also instead of supply power using microusb, connect two line from the RT1050 EVM to the USB port to supply power. 

1. After connect a ECG simulator to the ADS1292 EVM, I debug in the RT1050 board to communicate with ADS1292. When the DRDY interrupt is trigger, the ECG data can be read from SPI. But some of the data seem to be incorrect. For example, the packet like this,  C0 00 00 7F FF FF 80 00 00， this means the measure voltage is out of VREF voltage. 

2. On the RT1050EVM, I can send ADS1292_START and ADS1292_STOP command successfully. The ADS1292 response the two commands. But other commands such as  ADS1292_RDATAC, ADS1292_SDATAC, ADS1292_RREG, it seems ADS1292 has no response on these commands.

Does my connection of ADS1292 on the MSP430 EVM have any fault? Or some other pins should also connected to the RT1050? 

Please give some advice if any.

Thank you very much.

  • 0
    Prodigy 160 points

    Part Number: ADS1292ECG-FE

    Hi everyone,

    I purchased an ADS1292 ECG evm board for debugging.  Our development platform is NXP RT1050. Because ourselves hardware is not ready yet, I used a RT1050 EVM board to connect the ADS 1292 on the 

    ADS1292 ECG evm board. 

    The connection is like this: disconnect these ADS1292 pin from the MSP430:  DRDY, DOUT, SCLK, DIN, CS,  START, PWDN/RESET.  Connect these pin to the RT1050 EVM board. Also instead of supply power using microusb, connect two line from the RT1050 EVM to the USB port to supply power. 

    1. After connect a ECG simulator to the ADS1292 EVM, I debug in the RT1050 board to communicate with ADS1292. When the DRDY interrupt is trigger, the ECG data can be read from SPI. But some of the data seem to be incorrect. For example, the packet like this,  C0 00 00 7F FF FF 80 00 00， this means the measure voltage is out of VREF voltage. 

    2. On the RT1050EVM, I can send ADS1292_START and ADS1292_STOP command successfully. The ADS1292 response the two commands. But other commands such as  ADS1292_RDATAC, ADS1292_SDATAC, ADS1292_RREG, it seems ADS1292 has no response on these commands.

    Does my connection of ADS1292 on the MSP430 EVM have any fault? Or some other pins should also connected to the RT1050? 

    Please give some advice if any.

    Thanks.

  • 0
    TI__Guru**** 180831 points
    Hi jszhang,

    It looks like you've posted the same question twice, so we merged the two together. It's difficult to say what the issue may be. It could be your wiring, maybe a loose solder connection, or power issue. Send along screen captures of your SPI communications, that might help us help you figure out where the problem is.
  • 0 in reply to Tom Hendrick
    Prodigy 160 points

    Hi Tom Hendrick，

    Thank you for you advice.

    I think I have succeeded debugging the ADS 1292 SPI communication.

    I have resolve the problem that the commands can't be responsed successfully. The WREG, RREG, SDATAC commandS have no response.  The reason is:  When sending multi-byte commands,  a 4 tCLK period must separate the end of one byte (or opcode) and the next.  If CLK is 512 kHz, then tSDECODE (4 tCLK) is 7.8125 μs.  My SPI master baudrate is 500 000, the SPI master delay only 2us between sending two bytes. So ADS1292 can't receive the multi-byte commands successfully.  When sending commands, change the baudrate to 125 000 will resolve this problem.

    I have received the ECG wave data samples. The input signal is normal ECG wave with a heart rate 72. But my received ECG wave samples look strange. The ECG wave I received from ADS1292 is like this, see the attach file. The sample rate is 500.

    Why does the wave look like this? If the small peaks is because the power frequency interference, why does the interference peak so high? 

    I don't know if the wave is correct, or it is correct , just need filter. Please give some advice base your experience. 

    Thank you very much.

  • 0 in reply to jszhang
    TI__Guru**** 180831 points
    Hi jszhang,

    It's good to hear that you resolved your SPI communications issues. The zoomed in portion of you wave form looks reasonable to me, the higher peaks may be due to 50/60 Hz or 'motion artifacts'. Since your original question was related to your SPI communications, I'm going to close this post for now. Keep up the good work!