ADS1262 and 2.2 SPI TFT (Two SPI Slave) with Arduino

Question

I am interfacing two SPI slave module i.e. ADS1262 and 2.2 SPI TFT with the Arduino Ethernet board.

When I test each device on its own it works. Initially, I interfaced the TFT to the Arduino and it is working fine. Likewise, the example code of ADS1262 is working fine when I am running it alone.

So after successfully running the TFT alone, I then wire-up the ADS1262, add the corresponding code, however the ADS1262 doesn't seem to respond.

I think the issue may be related to the ADS1262_CS or ADS1262_START or ADS1262_DRDY pin sequence to access the ADS1262.

I have used the ProtoCentral_ads1262 library from GitHub and have used the example code.

From Comments:
We have already reserved D10 for Ethernet Controller and D4 for SD Chip select. The issue is, how to communicate both of them, one by one. I can access one of them only when code is prepare for both devices.

---

// Portion of the code is given here

// https://github.com/adafruit/Adafruit_ILI9341 library used for TFT

// Code start from here


for(j=initvalue;j<=finalvalue;j+=x)
{ 

      dacvalue=((j*5)/65535);

      writeValue(j);

      tft.fillRect(30,150,70,28,ILI9341_BLACK);

      tft.setCursor(30,150);

      tft.println(dacvalue,3); // dac value is showing on TFT

      Serial.println(dacvalue,3);

// ADS1262 is need to communicate here as per https://github.com/Protocentral/ProtoCentral_ads1262 library

// Which pins are need to control here to communicate with ADS1262???    

      volatile int p,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(p = 0; p <5; p++)
      {
        SPI_RX_Buff[SPI_RX_Buff_Count++] = *(SPI_RX_Buff_Ptr + p);              
      }
      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
        Serial.println("sads1262Count:");
        Serial.println(sads1262Count);
        resolution = (double)((double)VREF/pow(2,31));       //resolution= Vref/(2^n-1) , Vref=2.5, n=no of bits
        Serial.println(resolution,15);
        volt_V      = (resolution)*(float)sads1262Count;     // voltage = resolution * adc count
        volt_mV   =   volt_V*1000;                           // voltage in mV 
     tft.setCursor(166,150);
     tft.println(volt_mV,3); } //not printed on TFT

In above code, ADS1262 is not activated so not giving value on serial window or TFT.

How to activate the ADS1262 module.

Answer 1

I would suggest that

1) you debug individual code and to make sure that they work separately before integrating them.

2) you put those code pieces in logical blocks. for example, you are likely going to read something from the adc and displaying it on the lcd. so your code flow should be something like this:

  vol_adc = ad1262_read(ADC1_CH); //read analog from ADC1_CH
  vol_mv = adc2mv(vol_adc); //convert the adc results to mv
  lcd_display(vol_mv);  //display vol_mv on the lcd

this approach allows for much easier programming and debugging for you and your readers.