ProtoCentral ADS1262 with Feather M0 (SAMD21)

[LAWBear]

Might any of the ADS1262 wizards have a code example for the SAMD21 using a Feather M0 adalogger (includes SD on SPI)?
Ongoing challenges with SPI interface to M0 along with native SD on MC
Many thanks in advance for your kind guidance
Analog_data_logger_ADS1262_schematic.pdf
.

[LAWBear]

Having found and testing a simple ADS1262 example, it seems all data values are "zero". Several other simple SPI examples also show only "zeros', or "-1", with only other device is internal SD card on Feather M0 (CS 4). Operating ProtoCentral ADS162 on 5V, and using level converters on digital connections. PLEASE advise suggestions or alternate example.

Slightly modified "ads1262.h" for pin connections for Feather M0 Adalogger> ;

``////////////////////////////////////////////////////////////////////////////////////////////
// Demo code for the protocentral-ads1262 sensor breakout board
//
// Copyright (c) 2013 ProtoCentral
//
// This example measures raw capacitance across CHANNEL0 and Gnd and
// prints on serial terminal
//
// this example gives differential voltage across the AN0 And AN1 in mV
// Hooking-up with the Arduino
//
// |ads1262 pin label| Pin Function |Arduino Connection|
// |-----------------|:--------------------:|-----------------:|
// | DRDY | Data ready Output pin| D6 |
// | MISO | Slave Out | D12 |
// | MOSI | Slave In | D11 |
// | SCLK | Serial Clock | D13 |
// | CS | Chip Select | D7 |
// | START | Start Conversion | D5 |
// | PWDN | Power Down/Reset | D4 |
// | DVDD | Digital VDD | +5V |
// | DGND | Digital Gnd | Gnd |
// | AN0-AN9 | Analog Input | Analog Input |
// | AINCOM | Analog input common | |
// | AVDD | Analog VDD | - |
// | AGND | Analog Gnd | - |
// -------------------------------------------------------------
//
// This software is licensed under the MIT License(http://opensource.org/licenses/MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
// NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
// For information on how to use, visit https://github.com/Protocentral/ProtoCentral_ads1262
//
//////////////////////////////////////////////////////////////////////////////////////////

#include <SPI.h>
//#include <SoftwareSerial.h>
#include <math.h>
#include <ads1262.h>

#define PGA 1 // Programmable Gain = 1
#define VREF 2.50 // Internal reference of 2.048V
#define VFSR VREF/PGA
#define FSR (((long int)1<<23)-1)

ads1262 PC_ADS1262; // class

float volt_V=0;
float volt_mV=0;
volatile int i;
volatile char SPI_RX_Buff[10];
volatile long ads1262_rx_Data[10];
volatile static int SPI_RX_Buff_Count = 0;
volatile char *SPI_RX_Buff_Ptr;
volatile int Responsebyte = false;
volatile signed long sads1262Count = 0;
volatile signed long uads1262Count=0;
double resolution;

void setup()
{
// initalize the data ready and chip select pins:
pinMode(ADS1262_DRDY_PIN, INPUT); //data ready input line
pinMode(ADS1262_CS_PIN, OUTPUT); //chip enable output line
pinMode(ADS1262_START_PIN, OUTPUT); // start
pinMode(ADS1262_PWDN_PIN, OUTPUT); // Power down output

Serial.begin(9600);
PC_ADS1262.ads1262_Init(); // initialise ads1262
delay(5000);
Serial.println("ads1262 Initialised successfully....");
delay(5000);
}

void loop()
{
volatile int i,data;

if((digitalRead(ADS1262_DRDY_PIN)) == LOW) // monitor Data ready(DRDY pin)
{
SPI_RX_Buff_Ptr = PC_ADS1262.ads1262_Read_Data(); // read 6 bytes conversion register
Responsebyte = true ;
}

if(Responsebyte == true)
{
for(i = 0; i <5; i++)
{
SPI_RX_Buff[SPI_RX_Buff_Count++] = *(SPI_RX_Buff_Ptr + i);
}
Responsebyte = false;
}

if(SPI_RX_Buff_Count >= 5)
{
ads1262_rx_Data[0]= (unsigned char)SPI_RX_Buff[1]; // read 4 bytes adc count
ads1262_rx_Data[1]= (unsigned char)SPI_RX_Buff[2];
ads1262_rx_Data[2]= (unsigned char)SPI_RX_Buff[3];
ads1262_rx_Data[3]= (unsigned char)SPI_RX_Buff[4];

uads1262Count = (signed long) (((unsigned long)ads1262_rx_Data[0]<<24)|((unsigned long)ads1262_rx_Data[1]<<16)|(ads1262_rx_Data[2]<<8)|ads1262_rx_Data[3]);//get the raw 32-bit adc count out by shifting
sads1262Count = (signed long) (uads1262Count);      // get signed value
resolution = (double)((double)VREF/pow(2,31));       //resolution= Vref/(2^n-1) , Vref=2.5, n=no of bits
volt_V      = (resolution)*(float)sads1262Count;     // voltage = resolution * adc count
volt_mV   =   volt_V*1000;                           // voltage in mV
Serial.print("Readout voltage");
Serial.print(" : ");
Serial.print(volt_V);
Serial.print(" V ,");
Serial.print(volt_mV);
Serial.println(" mV");

}

SPI_RX_Buff_Count = 0;
}

float mapfloat(float x, float in_min, float in_max, float out_min, float out_max)
{
return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}''