ads1298r

Hello Tom,

Thanks for your reply,from your post it was clear that start pin can be any of GPIO.I have some other questions regarding the jumper3 pins like J3.2,J3.6,J3.8 and J3.12.

J3.2 is shown as CLKSEL,as i am not using MMBO board,to which type of pin i should connect?What is the purpose of this pin?

J3.6 is shown as GPIO1,to which type of pin i should connect?What is the purpose of this pin?

J3.8 is shown as RESETB,to which type of pin i should connect?What is the purpose of this pin?

J3.12 is shown as GPIO2,to which type of pin i should connect?What is the purpose of this pin?

Hi Tom,

I need some clarification regarding MSP430G2121.Why this Controller is used?What is the purpose of this controller?Is it Compulsory to use it?Please help me in this regard.

Thanks,

Sravan.

Hi Sravan,

Following the schematic in the ADS1298RECGFE-DPK Users Guide, the signals in question from J3 (page 80 of the UG, page 5 of the schematic) all connect to the ADS1298R on page 2 of the schematic.

CLKSELis described in the ADS1298R data sheet - this pin allows you to use the internal oscillator of the ADS1298R.  A logic 1 on the pin configures the ADS1298R to use its internal oscillator as the master clock for the modulator.  Technically you can leave the CLKSEL jumper open (there is a pull up resistor on the EVM to CLKSEL) if your intention is to use the internal oscillator.  In this case, you would want to disable the oscillator found at OSC1 (page 2 of the schematic) by moving the shunt on JP19 to cover pins 2-3. 

GPIO1 and GPIO2 are also described in the data sheet.  These are two of the four GPIO pins coming from the ADS1298R - you can leave them open or tie them to a GPIO on your processor.  If you configure them as GP outputs on the ADS1298R, you need to configure the processor for GP inputs and vise versa.

RESET is also defined in the data sheet.  The RESETB net ties directly to the RESET pin of the ADS1298.  You can use a GP output from your processor to control this line or you can simply leave the connection open.  There is a pull up resistor on this line as well (R6, page 2) that keeps the pin at logic 1.  If you want to be able to reset the part from your controller, you can toggle the RESET pin low or send the RESET command.

Sravan,

The MSP430 device along with U11 and U12 on page two of the schematic are there to 'simulate' the respiration function.  The MSP430 simply provides a square wave to the comparator (U12) which drives and analog switch (U11) that connects R76 and R77 in parallel.  The delta in impedance can then be measured in the ADS1298R. 

So, no - the MSP430 is not compulsory.  It is programmed to give a 0.1 through 0.5Hz square wave out which is selectable in our software GUI.  The default rate is 0.3Hz.  If you wish to input your own respiration test signal, you can do that by moving the shunt on JP36 to short pins 2-3 and apply a 3V square wave signal at J6. 

Hello Tom,

Thanks for the reply.

Thanks,

Sravan.

Hello Tom,

Thank you very much for your reply.I will make the connections as you suggested.But in MMBO Board J3 pins are assigned as follows:

J3.2---->FSX0--------  McBSP0 transmit frame synchronization.

J3.6---->CLKR0------McBSP0 receive clock. CLKR0 serves as the serial shift clock for the serial port receiver. At reset, this pin is in high-impedance mode.

J3.8---->FSR0--------McBSP0 receive frame synchronization. The FSR0 pulse initiates the data receive process over DR0. At reset, this pin is in high-impedance mode.

J3.12---->CLKX0-----McBSP0 transmit clock. CLKX0 serves as the serial shift clock for the serial port transmitter. The CLKX0 pin is configured as input after reset.

All the above functionalities are not supported by my processor.Is there is alternative for these functionalities.

Please help me.

Thanks,

Sravan.

Sravan,

J3 on the MMB0 is connected to an I2C expansion port, so you must be talking about J3 on the ADS1298 board.  The Users Guidefor the ADS1298R (page 20, Table 7) shows the pin out for the serial communication header J3 on the eval board.  Not sure where you are getting the above information from, but the nomenclature (FSx, FSr, CLKx and CLKr) comes from the McBSP port on the TMS320VC5509 which is on the MMB0.  The pin numbers are wrong as well - the CLKx would be pin 3, CLKr pin 5, FSx is pin 7 and FSr is pin 9.  Let me know what document you are getting this information from and I'll try to get it corrected.

Once you remove the ADS1298RECGFE-PDK from the MMB0, you only need the signals we've previously discussed (and power of course...).

Hi Tom,

I have one more doubt regarding NI(not installed components),what i have to do.In Bom also there are no details of not installed components.

Please help me.

Thanks,

Sravan.

Hi Tom,

I have one more doubt regarding NI(not installed components),what i have to do.In Bom also there are no details of not installed components.

Please help me.

Thanks,

Sravan.

Hi Tom,

I have some doubts.Please help me in this regard.In respiratory circuit of ads1298r,there are not installed opamps,and in page 1 of schematics there are protection diodes from D1-D9.I would like to know the components names and their foot prints.You are only my hope.Please help me in this regard.

Thankyou,

Sravan.

Hi Tom,

I am in great hurry,please help me.Opamps like U13A,U13B,ics likeU3,U4 and diodes like D1-D10 are not installed components,I would like to know the names and foot prints of the same.Please help me.Is these are compulsory to be placed?

Thanks,

Sravan.

Please see this post:

http://e2e.ti.com/support/data_converters/precision_data_converters/f/73/t/108017.aspx

Hi tom,

I need some information regarding MSP430.Actually i am not going to use any software in order to generate ecg and respiration signals.I am going to connect respiration and ecg electrodes through connector to the board.As MSP430 is used to simulate respiration.Is there is a need for me to use MSP430 in my board.Why sma jack is used with msp430.Please give me the reply.

Thanks,

Sravan.

Hi Sravan,

See THIS post for information on the MSP430 details, when concerning the ADS1298R. As Tom stated there, the MSP430, along with the analog switch and comparator, is part of the simulation circuit and are not needed on a formal (end application) design. The SMA connector allows for connecting an external function generator (further details on page 59 of the User's Guide), as opposed to using the onboard test signal generator (MSP430, comparator, and analog switch).

Regards,

Michael

Hi Michael,

Thanks for reply,but i want to use the respiration circuit on the ads1298r ece fe.If i dont use msp430  what type of  input i should give to U12 2nd pin  on page 2 of schematics.

I am using lpc2478 arm controller instead of TMS320VC5509A i.e., i am not using mmbo board,there is a header J7 in sheet 5 of schematics page,what type of pins i have to connect to J7.2 and J7.3. from my lpc2478.

Please help me in this regard.

Thanks,

Sravan.

Sravan,

Let me try to expand on Tom's previous post. The MSP430G2121 on the ADS1298ECG-FE board is there to help simulate respirations. It is factory programmed (through J7) to create a square wave of 0.1 to 0.5Hz. The frequency is selectable in the GUI as 0.1, 0.2, 0.3 (default), 0.4 or 0.5Hz. That signal is fed through JP36 to a comparator (U12 pin 2) and the output of the comparator drive the analog switch (U11). If you want to use your own signal generator to simulate respiration, you can apply a square wave to the SMA connector (J6) and move the shunt on JP36 to cover pins 2-3.

The MSP430 is there only to help you evaluate the respiration function without having to connect additional test gear to the EVM. You do not need to put anything from your processor into J7. J7 is there to accommodate the Spy-Bi-Wire Interface of the MSP430G2121 only, which is how we programmed the device to generate the square wave mentioned above.

Regards,

Michael