ADS1292R Communication

[susane]

Hello every one, i am an engineering student and i have been given a project, i want to communicate with ADS1292R with my Arduino UNO,
I have used the data sheet connections provided on page no 60.
i am using 4 wire SPI configuration, and for a good starting point, i just want to read a basic register with address 0x00, so i know that my communication is successful, but i am not able to do so,

Here is my code

#include <SPI.h>

int ADS1292_DRDY_PIN = 6; /// Not used for now
int ADS1292_CS_PIN = 10; ////// Working
int ADS1292_START_PIN = 5; /// Working
int ADS1292_PWDN_PIN = 4;////// Working
int ADS1292_CLK_SEL = 3; /// Working


int dat2 = 0;
int dat1= 0;



int RegData1 = 0;
int RegData2 = 0;
int RegData3 = 0;
int RegData4 = 0;
int RegData5 = 0;
int RegData6 = 0;





void setup() {
pinMode(ADS1292_DRDY_PIN, INPUT); //6
pinMode(ADS1292_CS_PIN, OUTPUT); //10
pinMode(ADS1292_START_PIN, OUTPUT); //5
pinMode(ADS1292_PWDN_PIN, OUTPUT); //4
pinMode(ADS1292_CLK_SEL, OUTPUT); //3



//////////// Power up sequence////////////
delay(10);
digitalWrite(ADS1292_PWDN_PIN, HIGH);
delay(9000);
digitalWrite(ADS1292_PWDN_PIN, LOW);
delay(100);
digitalWrite(ADS1292_PWDN_PIN, HIGH);
delay(1000);
////////////////////////////////////////////


///// Set CLKSEL to 1////////////

digitalWrite(ADS1292_CLK_SEL, LOW);
delay(100);
digitalWrite(ADS1292_CLK_SEL, HIGH);
delay(10);
//////////////////////////////////////////



/////// Setting start pin to LOW////////
digitalWrite(ADS1292_START_PIN, LOW);
delay(100);

SPI.begin();
SPI.beginTransaction(SPISettings(1000000,MSBFIRST,SPI_MODE1));

delay(1000); // Wait for SPI to begin

Serial.begin(9600);


}




void loop() {
// Sending the first command to ADS for SDAC so registers can be written

digitalWrite(ADS1292_CS_PIN, LOW);
delayMicroseconds(5);
SPI.transfer(0b00000010); //// SPI Command for Wakeup
delayMicroseconds(5);
SPI.transfer(0b00010001); //// SPI Command to STOP read data continous mode
delayMicroseconds(5);


SPI.transfer(0b00100000); // Read register command
delayMicroseconds(5);
SPI.transfer(0b00000000); // Number of Registers to read
delayMicroseconds(5);
RegData1 = SPI.transfer(0b00000000);// Dummy Data
delayMicroseconds(1);
RegData2 = SPI.transfer(0b00000000);// Dummy Data
delayMicroseconds(1);
RegData3 = SPI.transfer(0b00000000);// Dummy Data
delayMicroseconds(1);
RegData4 = SPI.transfer(0b00000000);// Dummy Data
delayMicroseconds(1);
RegData5 = SPI.transfer(0b00000000);// Dummy Data
delayMicroseconds(1);
RegData6 = SPI.transfer(0b00000000);// Dummy Data
delayMicroseconds(1);

digitalWrite(ADS1292_CS_PIN, HIGH);



Serial.print(RegData1,HEX);
Serial.print("\t");
Serial.print(RegData2,HEX);
Serial.print("\t");
Serial.print(RegData3,HEX);
Serial.print("\t");
Serial.print(RegData4,HEX);
Serial.print("\t");
Serial.print(RegData5,HEX);
Serial.print("\t");
Serial.print(RegData6,HEX);
Serial.print("\n");




}

If someone has experience with arduino and have done an SPI communication with this device, please help me

 

[KlausST]

Hi,

i am using 4 wire SPI configuration, and for a good starting point, i just want to read a basic register with address 0x00, so i know that my communication is successful, but i am not able to do so,

* how do you know that communication is successful?
* What does this mean? "I´m not able to do so"

If the master starts an SPI communication, it will recieve data ... how do you know it does´t work?

Please give detailed error descriptions, otherwise it is impossible to help you.

Klaus

 

[susane]

Sorry about my bad explanation,i am new to these forums,
the problem is that when i am reading register 0x00, all i am getting is a stream of "0" on the output.
and by successful communication i mean that when i will get the correct register value, i will be sure that my communication is successful.

All i need is a code for my arduino that can start the device and read the register 0x00 and print on serial monitor.

 

[KlausST]

Hi,

Could you please post your schematic?

I´m going to your task.

all i am getting is a stream of "0" on the output.

This means the UART output?

***
You say you get "0". For us it is hard to see if "0" is a valid value or not. We need to go through the datasheet spending some time to find out what are valid values.
I assume you expect "0x73". Is this correct?

***
On first sight I can´t find out what´s wrong.

Do yo have a scope (2 channels at least)? Then show us the diagram of communication. Set trigger on falling edge of CSn.

Klaus

 

[susane]

This is the Circuit i am using.


***********
And i am using the ARDUINO framework so the output is displayed on the serial monitor of arduino framework

*************
And yes you are right i am expecting the value "0x73"
*******
Just a small update that i want to give to you is that, i just found out that my arduino was giving a 5v output and the ADS1292R is capable of reading signal within the range of 1.8 to 3.6
so now i have to use a logic converter or i have to modify my arduino to give a 3.6v clock.

But i dont know if that was causing the problem or what else.
But now i should add a level converter and then i will upload the pictures from a scope.

Thanks a lot for such quick and helpfull response from you klaus
i will update all the information soon on this thread and thn we can discuss more.

 

[KlausST]

Hi

Arduino to ADC is 5V-->3.3V (Btw.: This may kill the ADC! Read datasheet.)
ABSOLUTE MAXIMUM digital input voltage is: DVSS – 0.3 to DVDD + 0.3 (in V)
A solution can be
* a current limiting resistor (I don´t recommend this)
* a two resistor voltage divider. (often a good solution. Especially because you already have the series resistor on your PCB)
* A 3V3 supplied gate with %V tolerant inputs
* A true 5V to 3V3 coltage converter IC.


But back: ADC to Arduino is 3V3 to 5V. What is the arduino´s valid high level? I expect about 0.7 x VCC = 0.7 x 5.0V = 3.5V.
The ADC high output level min. is 0.9 x DVDD = 0.9 x 3.3V = 3.0V

Often the interface form 3.3V to 5V works without problems. But it often is OFF specification.
I recommend to use a HCT buffer (mind the "T". It tells that it works on TTL input levels. High = 2.0V. So 3.0V is well within)

Good luck

Klaus

 

[susane]

Hi

Thanks a lot for the information, This was really helpfull
Now atleast i know what was wrong with my hardware, i will fix this issue and will be back here for more information.

Thanks Klaus