problem arduino SPI read from AD7792

Projects Programming
1

trying to communicate arduino with AD7792 which is a 16-bit ADC via SPI

however keep getting '0's in the serial monitor
any help would be appreciated

code looks like this:

#include <SPI.h>

const int CS = 10;//define chip select pin on Nano 33 BLE Sense
const byte readDeviceID = 0b01100000; //read command for ADC communicator 
byte deviceID;//8-bit register size

void setup() {
Serial.begin(9600);
 while (!Serial);
  
pinMode(CS, OUTPUT);
digitalWrite(CS, HIGH);
SPI.begin();
}

void loop() {
SPI.beginTransaction(SPISettings(64000, MSBFIRST, SPI_MODE3));//ADC has internal 64kHz clock,SCK idle high,clock phase1 
digitalWrite(CS, LOW);
SPI.transfer(readDeviceID); // Write to the communicator to read ID register
deviceID = SPI.transfer(0); // get ID register value
digitalWrite(CS, HIGH);
SPI.endTransaction();

Serial.println(deviceID,BIN);
delay(1000);
}

details of AD7792 can be found here: https://www.analog.com/media/en/technical-documentation/data-sheets/AD7792_7793.pdf

2

Post a wiring diagram of your setup!

If you use a breakout board for the ADC post schematics of it!

3

According to the link you provided, the chip select line is active LOW (hence the CS with a bar over the top) but you set it HIGH which presumably disabled the chip.

Try reversing your logic to match the datasheet.

4

According to the link you provided, the chip select line is active LOW (hence the CS with a bar over the top) but you set it HIGH which presumably disabled the chip.

No, OP didn't. Setting CS default to HIGH (in setup()) is the way you should do it. Setting it LOW afterwards initiates an SPI transaction.