ADS1298 connection with MSP430F2272

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

Hi Tomas,

Can you tell us how you have the registers set in both the ADS1298 and MSP430 (for the SPI configuration)?  What OpCode are you sending to the device?

Hello Tom,

I have the registers set at ADS1298

Config1: 0x86

Config2 : 0x10

Config3 : 0xC0

LOFF : 0x00

CH1SET : 0x05

CH2SET : 0x05

CH3SET : 0x05

CH4SET : 0x05

CH5SET : 0x05

CH6SET : 0x05

CH7SET : 0x05

CH8SET : 0x05

RLD_SENSP : 0x00

RLD_SENSN : 0x00

LOFF_SENSP : 0x00

LOFF_SENSN : 0x00

LOFF_FLIP : 0x00

GPIO : 0x0F

PACE : 0x00

RESP : 0x00

CONFIG4 : 0x00

WCT1 : 0x00

WCT2 : 0x00

Before send the register setting I set PWDN pin = 1, Reset pin = 1, SELCLK pin = 1, delay 200ms, RESET (by chip pin) then send SDATAC.

After setting, I set START = 1 (START pin) and send RDATAC to ADS1298

Between setting or command, I delay 100us.

At MSP430F2272, I set the MCLK = 16MHz.

The SPI setting is

UCB0CTL0 = UCMSB + UCMST + UCSYNC;

UCB0CTL1 = UCSSEL_2;

UCB0BR0 = 3;

UCB0BR1 = 0;

UCB0CTL1 &= ~UCSWRST;

Thanks a lot

Best regards,

Tomas

Hi Tomas,

The values at first glance for the registers seem fine.  I really don't see any reason why there should be an issue.  Can you get a 'zoomed' in screen shot of the first SPI transmission showing the status register and perhaps a schematic showing the connections around the ADC?

Hi Tom,

I write a document, please read the attachment.

Thanks a lot

Best Regards,

Tomas

Hi Tomas,

I looked again at the register settings you use and did notice that you have BIT 5 in CONFIG2 cleared - that bit should be set, default is 0 but it needs to be written to 1.  The long fly wires between the F2272 and the ADS1298 may be causing some communication issues.  Have you tried simply reading back the configuration registers to verify that you can change/read back values?  I know you said you were able to turn on/off the clock output, but have you verified any other settings?

Hi Tom,

I set BIT 5 in CONFIG2, it has the same issue.

I read back all the setting after set register. Setting is right even I set other value of setting.

I will try to let the wires shorter between the F2272 and the ADS1298.

Thanks a lot,

Best Regards,

Tomas 

Hi Tom,

I let the wires shorter between the F2272 and the ADS1298.

But it has the same issue.

Thanks a lot,

Best Regards,

Tomas 

Tomas,

At this point, all I can suggest is that you review the timing of the command/config inputs.  The ADS1298 uses an 8-bit op code and there are some delay requirements, please see page 38 of the data sheet for some of the detail.  Have you been able to verify that you can read back the default values from each of the device registers?

Hi Tom,

Yes, I read all of values back from each registers after I set, for check setting is right or not. I will check the delay time again about delay requirement.

Thanks a lot,

Best Regards

Tomas

Hi Tom,

I check all of the timing and delay requirements include Serial Interface Timing(page 13), RDATAC Usage(page 38) and Power-Up Timing Diagram(page 69).

All timings and delay meet the requirements but have the issue that only ch1 to ch4 have data.

Are there other things I have not pay attention?

Thanks a lot,

Best Regards,

Tomas

Hi Tomas,

Sounds like you've made a little progress.  What does the ID register (address 0x00) return when you query it?

Tomas,

i find the wire from MCU to ADS1298 is too long  from the picture, so pls let SPI_Clk run at a low frequency. pls try 1~3MHz.

reagards

Hawk

做 你能給我一個源代碼，以ADS1298為 MSP430 ，磷租賃？

我的郵件： asusm6nb@'gee'mail.com 

hi Tomas chang,

i am trying to interface ads1298 of EVM board with freesacle controller,the problem is i ll connect the corresponding pins of CS,DOUT ,DIN , SCLK and DRDY . i dont know hw connect remaining pins of J3  such as Reset,clksel,Ext_clk.please me dude.

Hi Tomas,

i am trying to interface ADS1298 EVM board with Freescale controller.

i am trying to read the ID register past 2 months ,i am not getting it.

will u please help me with your connections and program to read ID register. 

my connections are

ads1298 EVM                       freescale controller(master)

DIN                                         DOUT of SPI    

Dout                                       DIN of SPI

CS                                          CS of SPI

DRDY                                    connected to GPIO

SCLK                                     SCLK of spi

start                                        Tied low 

SCLK=12Mhz1565.code to read ID register.docx

and i have the program in a word document.