How can I program module ADS1115 with Arduino in Matlab?

Hello! I am trying to program the module ADS1115 with Arduino in Matlab, I have reviewed these pages however I cannot understand how it works, has anyone managed to program? I have also tried this code and it does not give me an ADC value consistent with what the multimeter shows me.

https://la.mathworks.com/matlabcentral/answers/286348-how-i-can-read-a-signal-from-asd1115-with-arduino-and-matlab

My code is:

ar=arduino('COM4','Uno','Libraries','I2C');

dev = device(ar,'I2CAddress','0x48');

%dev = i2cdev(ar,'0x48'); % creates i2c device object

writeRegister(dev,1,51075,'uint16');

ADC=readRegister(dev,0,'uint16');

Volt=1.024*(ADC/65536);

disp(Volt)

pause(2)

Answer 1

[Tom Rockett]

Hi Daniela

What is the voltage value that your code is giving you? If it is a factor of two out from the true value of 1.024V then the problem is due to using the wrong measurement mode of the ADS1115. You can try to set up your circuit to do a differential measurement, which will have the full 16-bits of resolution.

Best regards,

Tom

[daniela tovar]

Hi Tom,

I have configured the ads1115 from Matlab guiding me of this link:

https://la.mathworks.com/matlabcentral/answers/286348-how-i-can-read-a-signal-from-asd1115-with-arduino-and-matlab

The voltage I try to read varied with a potentiometer, from 0 to 3.3v and my ADC value should vary from 0 to 65536. However, it is not working that way, it gives me any random ADC value.

[Tom Rockett]

Hi Daniela

If the value is random then that sounds like you are reading noise. I'm not sure what to suggest, other than checking all of the connections in your circuit.

Here is a photo of the circuit that I used, which is similar to what you are trying to achieve (apart from the voltage divider in my case). I hope this helps.

Tom

[daniela tovar]

Hi Tom,

but what was your programming in matlab, I was connected the SCL and SDA to pins 4 and 5 of the arduino, so I see you connect it to the TX and RX. Truth?

Answer 2

[Tom Rockett]

Hi Daniela

I don't know where you've got TX and RX from, I haven't used them. What model of arduino are you using? The SCL and SDA pins on the ADS1115 are connected to the SCL and SDA pins on the arduino, respectively.

You can try replacing your writeRegister line with:

writeRegister(dev,1,37762,'uint16');

As this should enable the differential measurement (using pins A0 and A3 on the ADS1115). I suggest you follow my original example and read the ADS1115 data sheet (the section on the config register) to understand what difference this will make.

Best of luck,

Tom

[daniela tovar]

Hi Tom,

I was using pins A05 and A04 of the ARDUINO UNO since according to my data sheet these were SCL and SDA but you connect them on the other side of the arduino, I have checked again and I get that these are the SCL and SDA serial pins (check image) I do not know if that implies a difference I will try to configure it as you indicate, I tell you if I get a result.

Thank u

Daniela

[daniela tovar]

[Ahsan Sami]

Tom Rockett can u please help me in understanding how u design "37762" for both pins A0 and A3 and 51075 for only pin A0