I'm making this Electric Impedance Tomography project on proteus and the code is in arduino Mega1280. The circuit is working fine. The problem is when I'm simulating the circuit on proteus, the input voltages coming to A0 pin are being printed as 0 for some reason. Even though when I put a probe on that wire and it shows the voltage, arduino is printing as zero. Can someone help me?
Here is the code:
//library of the multiplexors
#include <CD74HC4067.h>
//library for calculating RMSvalues
#include <TrueRMS.h>
// loop period time in microseconds (time between samples)
#define LPERIOD 1000
// define the used ADC input channel
#define ADC_INPUT 0
// RMS window of 40 samples, means 2 periods at 50Hz
#define RMS_WINDOW 40
unsigned long nextLoop;
int adcVal;
int cnt=0;
// ADC full scale peak-to-peak is 5.00Volts
float VoltRange = 5.00;
// create an instance
Rms readRms ;
CD74HC4067 my_mux(22,23,24,25);
CD74HC4067 my_mux2(26,27,28,29);
CD74HC4067 my_mux3(30,31,32,33);
CD74HC4067 my_mux4(34,35,36,37);
void setup()
{
pinMode(A0, INPUT);
Serial.begin(9600);
Serial.println("LABEL,v");
Serial.print("DATA, ");
readRms.begin(VoltRange, RMS_WINDOW, ADC_10BIT, BLR_ON,CNT_SCAN);
readRms.start();
// Set the loop timer variable for the next loop interval.
//micros( ) Returns the number of microseconds since the Arduino board began running the current program.
nextLoop = micros() + LPERIOD;
//electrode 0 and 1//electrode 0 and 1
my_mux.channel(0);
my_mux2.channel(1);
for (int k=2;k<15;k++)
{
my_mux3.channel(k);
my_mux4.channel(k+1);
for(int i=0;i<500;i++)
{
// Read the ADC and remove the DC-offset
adcVal = analogRead(ADC_INPUT);
//take an instance again
readRms.update(adcVal);
cnt++;
//repeating the readings of one sample
if(cnt >= 500)
{
// publish every 0.5s
readRms.publish();
Serial.print(readRms.rmsVal,2);
Serial.println();
Serial.print("DATA, ");
cnt=0;
}
// wait until the end of the time interval
while(nextLoop > micros());
// set next loop time to current time + LOOP_PERIOD
nextLoop += LPERIOD;
}
}
}
void loop(){
}
inside the arduino IDE you should press Ctrl-T to autoformatting your code
The indentions are important to the reader of the code to easiyl see which command is inside which loop
The way you are calculating
nextLoop += LPERIOD;
while (nextLoop > micros());
does not handle a roll-over of micros() properly
all your code is inside function setup which means
the code runs through one single time and then the microcontroller is executing the empty
void loop() {
}
configuring the serial interface for 9600 baud means for printing something like
DATA, 10
which are 8 bytes each byte 10 bits (1 startbit 8 databits 1 stopbit)
8 * 10 * 1 / 9600 = 0,0083 seconds = 8,33 milliseconds
where you tried to read once every 1,0 milliseconds does not work.
Hey Stefan!
Im sorry I provided the code the way I did
Im relatively new to coding so I just copy pasted the code from a paper I found. And also the code provided didn't have any loop function. I just added an empty loop function so that the code can be compiled successfully.
Can you explain me how I can fix the issue?
It should be printing the voltage values but this is all it's printing
Yeha the voltage is no longer zero. I'm not sure how fast it exactly is but the voltage variation is rapid on the probe. By the way I provided the proteus file. Can you please check it if possible? I'm not very good at debugging and coding so Im assuming you might get a better idea if you check it
Tbh I copy pasted it from a research paper. The original code didn't have any loop function. I added an empty void loop just to avoid compilation error. And for this situation I just want 13 values so I didn't modify to put it in loop
however, just noticed that the values being printed are the max possible value, suggesting the input exceed the supply voltage on the board. do you need a voltage divder to reduce the voltage?
way 1:
play the lottery not knowing if you "win" = solve the problem after 50 minutes or 50 years.
way 2: learning the basics how programming works.
if you do not yet understand what an advice like
means
your knowledge about programming is way too less to get this to work.
Do yourself a favor and take at least some hours to learn the very basics of programming.
One way among a lot of others to do this is
Take a look into this tutorial:
It is easy to understand and has a good mixture between explaining important concepts and example-codes to get you going. So give it a try and report your opinion about this tutorial.
The analogRead() function makes the assumption that the function parameter refers to an analog pin, so you can use just the number 0 for A0, 1 for A1, etc. The danger with this is that pinMode(), digitalWrite(), and digitalRead() cannot make this assumption, and will instead use digital pin 0 when given the 0 instead of A0. If the code had used pinMode(ADC_INPUT) it would have set the mode of digital pin 0 (the Rx pin) instead of A0.
I think I see your problem. The input is always 1023 (5V) and you have 'baseline restoration' turned on. I think that means the RMS library is taking an average of your readings and calling that the baseline (0V) . Since your signal is not varying you never get a signal other than baseline. The RMS average is 0.
blr sets the automatically baseline restoration function on or off. Use the predifined constants BLR_ON or BLR_OFF.
