Problem adding multiple sensors

[ziatajo]

Hi,
Maybe I'm just too stupid, but I cannot even manage to add a second sensor.

I used the example and successfully connected a full-bridge loadcell to AIN0-AIN1.
Than I wanted to add a second full-bridge loadcell to AIN2-AIN3.
I just copied the code: Defined additional POS-NEG pins, and read the value:
voltage1 = adc1.readADC1(pos_pin1,neg_pin1); // read the voltage
voltage2 = adc1.readADC1(pos_pin2,neg_pin2); // read the voltage

However my data for both sensors is now just showing 0 or -1.

What am I doing wrong?

Thank you and best regards

[Molorius]

No need to self-deprecate! Let me make sure I understand your problem.
You were able to successfully use the example code. Then you changed the loop function to something like:

void loop() {
  long voltage1 = adc.readADC1(pos_pin1,neg_pin1);
  long voltage2 = adc.readADC2(pos_pin2,neg_pin2);
  Serial.print(voltage1);
  Serial.print(", ");
  Serial.println(voltage2); // send voltage through serial
  delay(1000); // wait 1 second
}

and now you are only getting 0 and -1. Is that correct?

[ziatajo]

Exactly, both sensor values are only 0 or -1 now.
I'm using an Adafruit Feather ESP32 if that helps. Let me know if you need something else.
Thank you for your help.

[Molorius]

Are you using 3.3V on DVDD and 5V on AVDD? The esp32 is not 5V tolerant, so the ads126x digital side needs to be run at 3.3V (or use level shifters). The ads126x analog side requires 5V to operate.

Try commenting out one of the voltage read lines, maybe there was an introduced change that messed with the reading.

I do not have an ads126x readily available, but I had problems with it when uploading new code to a microcontroller. Try uploading the code, disconnecting all power to your circuit for a few seconds, then power it back on.

[ziatajo]

That is a good point. I have a Step-Up for the 5V, but connected DVDD and AVDD to 5V now I changed that DVDD is on the 3.3V. Unfortunately it didn't change the result and it's still the same.
My code at the moment is:

#include <ADS126X.h>

ADS126X adc1; // start the class

int chip_select1 = 4; // Arduino pin connected to CS on ADS126X

long voltage1 = 0;
long voltage2 = 0;

int pos_pin1 = 0; // ADS126X pin AIN0, for positive input
int neg_pin1 = 1; // ADS126X pin AIN1, for negative input

int pos_pin2 = 2; 
int neg_pin2 = 3; 


void setup() {
 Serial.begin(115200);
 adc1.begin(chip_select1); // setup with chip select pin0.
 adc1.startADC1(); // start conversion on ADC1
 Serial.println("Reading Voltages:");
}

void loop() {

 voltage1 = adc1.readADC1(pos_pin1,neg_pin1); // read the voltage
 Serial.print(voltage1); // send voltage through serial
 delay(100);
 Serial.print(" , ");
 voltage2 = adc1.readADC1(pos_pin2,neg_pin2); // read the voltage
 Serial.println(voltage2); // send voltage through serial
 delay(100);
} 

I only get 0 and -1 (don't know when it is changing between the two).
When I comment out one of the "voltagex=adc1.readADC1...." lines the still active sensor works. (it works for both sensors)
I also changed the delays but longer or shorter didn't help too.

EDIT: I just tried it with a Teensy 3.2 instead of the ESP32. I get the same "error". One sensor works, two sensors don't.

[Molorius]

I think I know what the problem is. As a quick test, could you try reading each voltage twice? So:

void loop() {
 adc1.readADC1(pos_pin1,neg_pin1);
 voltage1 = adc1.readADC1(pos_pin1,neg_pin1); // read the voltage
 Serial.print(voltage1); // send voltage through serial
 delay(100);
 Serial.print(" , ");
 adc1.readADC1(pos_pin2,neg_pin2);
 voltage2 = adc1.readADC1(pos_pin2,neg_pin2); // read the voltage
 Serial.println(voltage2); // send voltage through serial
 delay(100);
} 

[SammyRamone]

We have exactly the same issue. We also tried you code from last comment and also only recieved "0,0". A fix would be great.
Reading just one of the sensors works perfectly well.
Btw, thanks for the library :)

[ziatajo]

I let the ADS1262 in my office over the weekend, thats why I could test it not before now.
As SammyRamone state, also with the double reading it doesn't work. However there is a small difference.
With reading each voltage twice, I always only get "0 , 0", as soon as I read it only once it will change between 0 or -1 (no pattern).

[q-bird]

Do you get the same problem with both of ContinuousMode and PulseMode?

[ziatajo]

How do I change that? :)

[q-bird]

You can go to README.md and find setContinuousMode() or setPulseMode()

[q-bird]

And pls also try to use this func void setDelay(uint8_t del) to see if it can solve something!

[ziatajo]

I changed it like the following. In two steps, first only the PulseMode(), than with delay. Both doesn't change anything. adc1.setContinuousMode(); + delay doesn't help too.

void setup() {
  Serial.begin(115200);
  adc1.begin(chip_select1); // setup with chip select pin0.
  adc1.setDelay(ADS126X_DELAY_8_8);
  adc1.setPulseMode();
  adc1.startADC1(); // start conversion on ADC1
  Serial.println("Reading Voltages:");
}

[q-bird]

With the PulseMode, then can you try something like this?

void loop() {
 adc1.startADC1();
 voltage1 = adc1.readADC1(pos_pin1,neg_pin1); // read the voltage
 Serial.print(voltage1); // send voltage through serial
 adc1.stopADC1();

 delay(1000);
 Serial.print(" , ");

 adc1.startADC1();
 voltage2 = adc1.readADC1(pos_pin2,neg_pin2); // read the voltage
 Serial.println(voltage2); // send voltage through serial
 adc1.stopADC1();

 delay(1000);
} 

(The purpose is just to figure out the problem we are encountering by using some different ways to read)

[ziatajo]

With this I get the same output as at the start:

Reading Voltages:
0 , -1
0 , 0
0 , -1
-1 , -1
-1 , 0
-1 , 0
-1 , 0
-1 , -1
0 , -1
-1 , 0
0 , -1
-1 , 0
-1 , 0
0 , -1
-1 , 0
-1 , -1

[ziatajo]

Hi,
Do you have any other ideas, how I could solve this?

Thank you.