[ADS1198] Programming ADS1198 using Arduino DUE

Spiros,

I'm moving your post to the correct forum.

Hello Brian,

Thank you for replying. I didn't answer sooner cause I didn't have a logic analyzer.

Below I present you my arduino code and result through the logic analyzer.

#include "SPI.h" // necessary library
int ss=11; // using digital pin 11 for SPI slave select
int clksel=13;//CLKSEL->1 for internal clock
int pwrdn=8;//active low
int reset=9;//active low
int start=10;
int drdy=12;

void setup() {
  Serial.begin(9600);
  Serial.setTimeout(2000);
  pinMode(ss, OUTPUT); // we use this for SS pin
  pinMode(pwrdn, OUTPUT);
  pinMode(reset, OUTPUT);
  pinMode(start, OUTPUT);
  pinMode(drdy, INPUT);
  pinMode(clksel, OUTPUT);
  SPI.setBitOrder(MSBFIRST);
  delay(200);
  digitalWrite(clksel, HIGH);
  digitalWrite(pwrdn, LOW);
  digitalWrite(reset, LOW);
  delay(1000);
  digitalWrite(pwrdn, HIGH);
  digitalWrite(reset, HIGH);
  digitalWrite(ss,HIGH);
  }

void loop() {
  delay(1000); //wait 1s for Power-On Reset
  SPI.begin(); // wake up the SPI bus.
  SPI.beginTransaction(SPISettings(2000000,MSBFIRST, SPI_MODE1));
  digitalWrite(ss,LOW);
  delay(200); //wait for 18*t_clk
  Serial.print("WAKEUP: ");
  Serial.println(SPI.transfer(0x02));
  delay(200);
  Serial.print("SDATAC: ");
  Serial.println(SPI.transfer(0x11)); 
  delay(200);

while(1)  {
  SPI.transfer(0b00100000);//read ID register
  delay(200);
  SPI.transfer(0);
  delay(200);1
  Serial.print("RREG ID: ");
  Serial.println(SPI.transfer(0)); 
  delay(2000);
  }
}

And here is what I get as a result:

An overall preview

The wake up command

The SDATAC command

And the three command for reading the register (2 commands and one 0 transfer to print)

And the rest of the transactions

I should mention that when I check my results through serial after some repetitions all I get back is zeros.

Spiros

Hello Brian,

thank you for taking the time to help me with this,

I could really use some help.

Here is the schematic, sorry it is a bit messy, I only made it for my pcb layout.

Let me remind you some connections.

I put the capacitors as they are in datasheet's page 63 instructions for a unipolar supply.

I've also grounded pins RESV1(31) and DAISY_IN(41) as it is mentioned at page 11.

I can control/read CLKSEL, DRDY, CS, START, RESET and PWDN pins using Arduino's digital pins 8-13.

I've connected Din(MOSI), Dout(MISO) and SCLK to Arduino's ICSP.

The supply is same for the analog and the digital part 3.3V.

Thank you, Spiros

Hi Brian,
VREFP is at 40.6mV.
According to datasheet's page 24 for internal reference it should be 2.4V. Am I correct?
Could it be a software issue or a board issue?

Is there any other way to test chip's functionality?

Spiros

I'm back after so much time to give an answer to this problem.

You were right after all Brian!

I got my professional pcb, did my soldering and now chip works fine. I can read registers and get the correct values.

My pcb layout was based on the demostration kit ADS1198ECGFE-PDK.

So i'm not completely sure what the problem was, if it was a pcb issue or now that I changed a bit my layout but it works.

Here is a picture of my pcb working as an arduino shield for my convienience.

Thank you very much for your support Brian.

Spiros