ADS1299EEGFE-PDK: Powering and communication of ADS1299FE Daughter board with Arduino

Hello Meghna,

Thank you for your post.

The ADS1299EEG-FE daughter board can be used as a standalone platform with another microcontroller. Power supplies and digital communication signals can be connected to the available test points or header pins. Be sure to share both power supplies and GND connections. You may refer to the User Guide for documentation about the hardware design.

Regards,

Ryan

Hello Ryan,

Thank you for your reply.

However, using the J4 connector, I'm unable to get 1.8V in TP9. Other test point voltages are fine. All the other jumpers are in default mode as per the User Guide. Please let me know what I'm missing here.

Here's the picture of the connections:

Hi Ryan,

The red wire (J4.10) is 5V.
The green wire(J4.9) is 3.3V and black is the GND.

With the J24 being shorted in 2-3 and the other Jumpers as shown in the above pictures, I'm assuming that I should be able to read/write the register values? Or am I missing anything here?

Hi Meghna,

You mentioned that you were unable to get 1.8V in TP9, so I assumed you were trying to use this as your DVDD supply. There is no need to measure 1.8 V on TP9 if you are using 3.3 V for DVDD with JP24 in the [2-3] position. The supply connections look correct now.

Regards,

Ryan

Hi Ryan, 
I am not able to Read/Write any Registers using Arduino. It's all zero.

I also tried with the MMB0 board but I'm unable to progress.  I've been following this link, but there still seems to be an error.

This is the screenshot of my device manager:

This is the screenshot of the register values:

This is my hardware:

Is there any updated instructions for the smooth operation of EVM GUI?

At present, I am just installing ADS1299EEGFE-PDK-SW. Do I need to install all 3 or only the 3rd one?

Hi 

Is there any update?

Hi Ryan!

I used the default setting according to section 2.5, and with the current jumper settings of J18 (as in the above picture, i.e. Pin 2-3 shorted in JP18), I could get the default values of the Registers on the EVM.

However, when I try reading the registers through SPI from Arduino UNO, I get FF for all. I went through various TI forum posts, but couldn't get a solution for me. This is the Arduino library I am using : https://github.com/conorrussomanno/ADS1299/tree/master. 

Could you help me debug this?

My connections are: 

The source code for the ADS library is: github.com/.../ADS1299.cpp

This is the code I am using:

#include <SPI.h>

//SPI Command Definitions (pg. 35)
const byte WAKEUP = 0b00000010; // Wake-up from standby mode
const byte STANDBY = 0b00000100; // Enter Standby mode
const byte RESET = 0b00000110; // Reset the device
const byte START = 0b00001000; // Start and restart (synchronize) conversions
const byte STOP = 0b00001010; // Stop conversion
const byte RDATAC = 0b00010000; // Enable Read Data Continuous mode (default mode at power-up)
const byte SDATAC = 0b00010001; // Stop Read Data Continuous mode
const byte RDATA = 0b00010010; // Read data by command; supports multiple read back

//Register Read Commands
const byte RREG = 0b00000000;
const byte WRET = 0b00000000;

//Arduino Uno - Pin Assignments;
// SCK = 13
// MISO [DOUT] = 12
// MOSI [DIN] = 11
const int CS = 10; //chip select pin
const int DRDY = 9; //data ready pin

const float tCLK = 0.000666;

boolean deviceIDReturned = false;

void setup() {

Serial.begin(9600);

// start the SPI library:
SPI.begin();
SPI.setClockDivider(SPI_CLOCK_DIV16); //Divides 16MHz clock by 16 to set CLK speed to 1MHz
SPI.setDataMode(SPI_MODE1); //clock polarity = 0; clock phase = 1 (pg. 8)
SPI.setBitOrder(MSBFIRST); //data format is MSB (pg. 25)

// initalize the data ready and chip select pins:
pinMode(DRDY, INPUT);
pinMode(CS, OUTPUT);

delay(10); //delay to ensure connection

digitalWrite(CS, LOW); //Low to communicated
SPI.transfer(RESET);
digitalWrite(CS, HIGH); //Low to communicated

//Set up ADS1299 to communicate
// digitalWrite(CS, LOW); //Low to communicated
//// SPI.transfer(START);
// digitalWrite(CS, HIGH); //Low to communicated

delay(10); //delay to ensure connection

}

void loop(){
//Serial.println("Time: "+ millis());
if(deviceIDReturned == false){
getDeviceID();
deviceIDReturned = true;
}
}

void getDeviceID(){
// SPI.transfer(START);
digitalWrite(CS, LOW); //Low to communicated
SPI.transfer(SDATAC);
SPI.transfer(0x20); //RREG
SPI.transfer(0x00); //Asking for 1 byte (hopefully 0b???11110)
byte temp = SPI.transfer(0x00);
digitalWrite(CS, HIGH); //Low to communicated

Serial.println(temp, BIN);

}

Hi Meghna,

My apologies for the typo - I was actually referring to JP19. This jumper connects the oscillator enable pin to the DVDD supply. Since CLKSEL is tied low through JP23, the ADS1299 will be expecting an external clock input from this oscillator. It looks like the enable pin for the oscillator can be left open and the output will still be valid, so there is no concern there.

Can you try separating the SDATAC command from the RREG command, using two separate frames? Also, when sending the RREG command, check your SCLK frequency and make sure it meets the tSDECODE timing requirement. If the time to send one byte is less than 4*tCLK, you may need to insert a small delay between bytes for the RREG command to be decoded properly.

Regards,

Ryan

Understood, thanks. I am able to read the registers on GUI with JP19 connected.

Could you help me with the exact connections and register settings on the GUI to view an 8 channel single-ended input EEG on the Analyzer?

I did go through the User Guide Section 7, but I am a bit confused:

1. I want to use BIAS_DRV as the bias electrode ( i.e I don't want an external electrode as Bias).
a) What are the jumper configurations and Register configurations for this? Is it the same as mentioned in Sec 4.6.2?
b) For register configurations, is there anything else I need to do other that the instructions on Pg 35 of the User Guide?

2. I was to use an external electrode connected  as Ref Electrode. 
a) For EEG measurement, is it recommended to use buffered or unbuffered? What Jumper and register configurations do I need for this?
b)  Can I use the electrode connected to channel 1 (J6.36) as Ref Electrode? I need to modify SRB2 bit of CH1SET register?  OR Do I need to connect the Ref electrode to JP25??

Is there anything else I need to keep in mind with respect to connections and register settings for EEG data collection with ADS1299FE PDK with MMB0 motherboard?

Hi Meghna,

Glad we resolved the register read issue on the GUI.

Please refer to section 7.1 of the User Guide for suggested connections for the BIAS and REF electrodes. To summarize, the BIAS_DRV signal is the output of the ADS1299's BIAS amplifier. This signal carries a DC mid-supply voltage used to bias the body relative to the AVDD/AVSS supplies of the ADS1299. It also can be configured to carry an AC common-mode signal which helps to suppress noise that couples onto the body/electrodes (i.e. 50/60 Hz power line noise).

If you want the reference electrode to be common to all channels, you can use the SRB1 pin of the ADS1299, which is internally routed to all INxN inputs. On the EVM, connect the reference electrode to JP25.6 and short JP8[1-2]. JP7 can be left open or in the [2-3] position.

In addition to the EVM User Guide, there are detailed sections about these function in the ADS1299 device data sheet. Please refer to sections 9.2.3.4 and the Applications section (10.2).

Regards,

Ryan

Hi, 

Thank you for your reply. I've read through the User Guide, however I am a bit confused. To start of, I am just trying with 1 channel ECG, before going to EEG. These are my Register configurations and H/W configurations. Seems like I'm just getting noise. Could you let me know how I can get cleaner ECG signals?

" It also can be configured to carry an AC common-mode signal which helps to suppress noise that couples onto the body/electrodes (i.e. 50/60 Hz power line noise). " ---  How do I do this?

Hi Ryan,

I am confused with the following reply, your reply, and the user guide :

You mentioned that -- "If you want the reference electrode to be common to all channels, you can use the SRB1 pin of the ADS1299, which is internally routed to all INxN inputs. On the EVM, connect the reference electrode to JP25.6 and short JP8[1-2]. JP7 can be left open or in the [2-3] position."

However, in another post, I saw this:

And on the User-Guide, it asks me to short 5-6 of JP25.

Please clarify. I am very confused with the BIAS_ELEC and REF_ELEC electrode positions, jumper settings and Register configuration. Please help.

Thank you so much. I am able to get a single ECG Signal now.

However, since my final application is for EEG, could you help me out with the correct register,  jumper configurations, and connections for the Reference and Bias electrodes?

To be more specific:

1. I have an external Bias Electrode connected to JP25.2. I have taken off the jumpers at JP6[1-2], JP25[1-2] and JP25[3-4]. Is this correct? 

2. I want to use an electrode connected to JP25.6 as the REF ELECTRODE. To ensure that this is the common reference for all the single-ended inputs, I enable SRB1 in MISC1.  JP8[1-2] are shorted; JP7 [2-3] are shorted. Is this correct?

3. What should be the settings for the following registers from the GUI: CONFIG3, LEAD Off Detections & Current Control Registers , BIAS Control Registers.

Please help me out with the above questions at the earliest of your convenience! 

Hi Ryan, any update??