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ADS1293 Evaluation board

Other Parts Discussed in Thread: ADS1293, ADS1293EVM

Hi there all

I have couple of questions regarding the ADS1293 and its evaluation board and your help is highly appreciated 

1- How can I enable the Bluetooth chip on the evaluation board and get the output signal from it ? and can I use the related software to show the signal on the PC using the Bluetooth not the cable ?

2- How can I know the exact data rate coming out from the board and what is the form of the output data ?

3- which pin has my converted final output and is it coming out through the cable when I connect it to my PC ?

And have a nice day all 

  • **TI EDIT February 20th 2019; FOR GENERAL ADS129x ASSISTANCE, PLEASE SEE NEW BIOPOTENTIAL FAQ LOCATED HERE**

    Hi there!

    Which board are you using? If you are using the regular evaluation board (www.ti.com/.../ads1293evm), it does not have an on-board Bluetooth chip.

    Please let us know.

    Thanks,
    Sergio

  • Thank you Sergio for your reply yes it is the evaluation board that I have , now allow me to ask another question :

    the other chip on the evaluation board is a micro controller but I don't understand what it does exactly so do you know how the data flow between the analog front end and the micro controller 

    And can I display the output through arduino uno deice using the SPI port on the board ? 

  • The microcontroller on the EVM is an MSP430F5529IPN. The microcontroller is used to read/write registers of the ADS1293, capture the data from the ADS1293 and send it to a PC running the Evaluation Software using the USB port.

    The flow of data between the ADS1293 and the MSP430 is done using the SPI interface of the ADS1293. You can find details about the SPI protocol of the device in the programming section of the ADS1293 datasheet.

    I don't think the source-code of the EVM firmware and the Eval Software are available, so I can't provide you details about the USB communication.

    Is your intention to connect your arduino device to J2 of the EVM? It sounds doable, but unfortunately I can't help you with that. I can tell you that you will have to deal with the MSP430 hanging from your SPI interface. In another post, it was recommended to erase the flash memory of the MSP430 (compiling and programming an empty Main loop) so it acts as a dormant SPI slave and does not interfere with the SPI communication between your arduino device and the ADS1293. But once you do so, you cannot use the Eval Software on the PC to configure/control the EVM. You will only depend on the arduino SPI interface.

    You can find the default EVM firmware hex file in the forum, if you need to revert back. Please let me know if you can't find it.

    Regards,

    Sergio
  • Thank you very much Sergio , this was very helpful and I couldn't find the EVM firmware hex file you referred to , so can you provide a link to that please 

    Regards 

  • Hi Shaimaa,

    You are welcome. Here is the link to the post that I was referring to: e2e.ti.com/.../1127685

    Regards,
    Sergio
  • Dear Sergio 

    Is it possible to read the data from the EVM through Matlab because I am having a problem identifying which port is my EVM using to make my code work properly , when I used the Device manager the EVM  appears as NSC_USB not under the ports and COMS 

    So do you know a way to help me know which port my EVM is using so I can correct this code :

     board = serial('COM1', 'BaudRate', 853, 'DataBits',8)

    Regards

  • Hi Shaimaa,

    The communication between the EVM and PC does not emulate a COM port, so it's not possible to read data as "EVM->usb->Matlab" using the default firmware of the EVM.

    Regards,
    Sergio
  • Thank you Sergio for your swift reply
    And may I arise the following question :
    How does the software acquire the data and read it from the EVM ?
    Is there any way for matlab to communicate with the EVM using the USB ?
  • You're welcome.

    The software uses a special USB driver, but there is no source or documentation available. Sorry, but I can't think of a way of easily tapping into the existing USB interface between the EVM and the PC.

    Sergio
  • Hi Sergio 

    How can I erase the flash memory of the MSP430 as recommended  in the previous post 

    Thanks 

  • Hi Shaimaa,

    You can follow step 4 in the following post to load a custom HEX file on the EVM using a bootstrap loader (BSL). In step (e), hold the SW2 button instead of the "BSL" button: e2e.ti.com/.../1127685

    I would recommend you to search the web or ask in the MSP430 forum how to compile and create a BSL text file for the MSP430 with an empty main loop. You may also want to present your purpose, as other users may be able to provide better alternatives for this part of your project.

    Regards,
    Sergio
  • Dear Sergio

    I bought 2 of the ADS1293 EVM couple of months back , and I have been working on one that I conducted a mass erase on which went successfully then I tried to use the HEX file via the MSP430 USB Firmware Upgrade example software to retrieve it back but nothing works and I get the error as in the picture attached

    so do you have any idea why this  happened?

    Another Question :

    I tried to connect the other EVM which I didn't conduct any erase or anything on , I only opened its case and as far as I remember used it just once but today when I connected it , it gave the same error as the picture below  , could it be that the board is burned due to touching it since it has no protection on it 

    Do you have any suggestions on how to fix this problem ?

    Regards

  • When you plug the EVM to the USB port, do you see an item listed in the Device Manager of your PC called "NSC_USB_WV5"?

  • Dear Sergio I re-uploaded the HEX file and now the EVM works just fine , yet I have another question , I am writing a code with Arduino Uno to read the registers of the EVM in the datasheet the first 8 bits of the command field send   in the SDI has 7 bits address and C7 is the read/write bit now if I want to write the value to register CH_CNFG  with the address of CH_CNFG =0x2f and I want to write to it this value VALUE_CH_CNFG = 0x32 

    I wrote this code :

    digitalWrite(ss, HIGH);
    delayMicroseconds(2);
    digitalWrite(ss, LOW);
    SPI.transfer(0x00);
    SPI.transfer(CH_CNFG);
    SPI.transfer(VALUE_CH_CNFG);

    how can I tell the spi that the first bit is a write with the value 0 cause in the registers map the value of the registers has 7 bits and the 8 is received

    where to put this write/read bit in the code ?

    Regards 

  • Hello Shaimaa,

    The command field is indeed 8 bit wide, and the most-significant bit would be the read/write bit.

    I don't know what the syntax of your code is, but for a write command, you can perform a bitwise AND of the register address and a hex value of 0x7F, such that bit 8 is always 0 after the bitwise AND operation.

    For a read command, you can perform a bitwise OR of the register address and a hex value of 0x80, such bit 8 is always 1 after the bitwise OR operation.

    Best regards,

    Sergio

  • Thank you Sergio that worked very fine 

    now I have preformed a read cycle for 1 channel and recorded the values I got from the arduion serial monitor and plotted the signal as shown in this picture below 

    my question is what is the used formula to convert the analog to digital in the EVM so I can reverse it and use it on my digital data I got to get the exact analog values to have a better plotting for the ECG

    Regards 

    Shaimaa 

  • Hi Shaimaa,

    You can use equation (13) in the datasheet, by solving for the term "VINP-VINM". Section 8.4.3 gives a brief description equation (13) and the variables used in the equation.

    On a different note, it looks like your data is missing bits. The ECG data of each channel is 24-bit wide, but it is split and stored as three separate bytes, which you should then recombine to produce your plot. For example, Channel 1 data is stored as:

    Register 0x37: upper byte
    Register 0x38: middle byte
    Register 0x39: lower byte

    Equation 13 will need the 24-bit wide value.

    Regards,
    Sergio

  • pullout jumper JP3, and use external power supply. You are good to go. No need to erase MSP430 flash. Check the schematic of the board. 

  • Hi Sergio,

    I am working on ADS1293EVM and trying to access the ADC data through the SPI interface.

    As you previously guided.



    1) I Did not connect the USB cable to the ADS1293EVM

    2) Removed jumpers from JP2 and JP3

    3) Applied +5V at JP1 between BATT+ and BATT-



    The ADS1293 chip is powered up. I checked the voltage from the following test points:

    · At VREF (located next to L1) voltage --2.4V

    · At RLDREF (located on the bottom, fourth red test point from left-to-right) voltage --1.5V

    · At DRDYB (located on J2 to the right of the ADS1293 chip) received --1.6V

    As per the guidelines on the DRDYB pin need to receive 3.3V, but I am getting voltage is 1.6V.

    Same thing I have verified at 20th pin of ADS1293 there also we are getting 1.6V.

    Please let me know this pin is output of ADS1239 or not, if so then when it will be set a clear.



    If it is the case, how I need to proceed now. Still, we can read ADC data from SPI. If it is kindly guided me how to do.


    If we can not read data from existing board. we are ready to purchase a new board, if you assure 100 percent we can access ADC data.


    I have one more quarry that, what is the sequence of data will receive through spi, chanel by chanel ADC data or all channels data together as a packet??



    Kindly guide me to come up from this issue.


    Thanking you!

    With Regards
    Nandini C
  • Hi Sergio,

    I am trying to contact you may times.
    I am working on ADS1293EVM and trying to access the ADC data through the
    SPI interface.

    As you previously guided.



    1)     I Did not connect the USB cable to the ADS1293EVM

    2)     Removed jumpers from JP2 and JP3

    3)     Applied +5V at JP1 between BATT+ and BATT-



    The ADS1293 chip is powered up. I checked the voltage from the following
    test points:

    ·         At VREF (located next to L1)  voltage  --2.4V

    ·         At RLDREF (located on the bottom, fourth red test point from
    left-to-right)  voltage  --1.5V

    ·         At DRDYB (located on J2 to the right of the ADS1293 chip)
    received    --1.6V

    As per the guidelines on the DRDYB pin need to receive 3.3V,  but I am
    getting voltage is 1.6V.

    Same thing I have verified at 20th pin of ADS1293 there also we are getting
    1.6V.

    Please let me know this pin is output of ADS1239 or not, if so then when it
    will be set a clear.



    If it is the case, how I need to proceed now. Still, we can read ADC data
    from SPI. If it is kindly guided me how to do.


    If we can not read data from existing board. we are ready to purchase a new
    board, if you assure 100 percent we can access ADC data.


    I have one more quarry that, what is the sequence of data will
    receive through spi, chanel by chanel ADC data or all channels data
    together as a packet??



    Kindly guide me to come up from this issue.


    Thanking you!

    With Regards
    *Nandini C*