Coding for multiple FSRs

[sp817]

I have this code which displays the output for one FSR. I would like to use arrays to display the output for 3, but am unsure of how to do so.

Thanks

float cf = 19.5; // caliberation factor

 

int ffs1 = A0; // FlexiForce sensor is connected analog pin A0 of arduino or mega. 

 

int ffsdata = 0; 

float vout; 

void setup()

{

  Serial.begin(9600); 

  pinMode(ffs1, INPUT); 

  

}

 

void loop()

{

  

 ffsdata = analogRead(ffs1);

vout = (ffsdata * 5.0) / 1023.0; 

vout = vout * cf ; 

Serial.print("Flexi Force sensor: "); 

Serial.print(vout,3); 

Serial.println(""); 

delay(100); 

  

}

[anon73444976]

Too much code!

const float cf = 19.5; // caliberation factor
const byte ffs1 = A0; // FlexiForce sensor is connected analog pin A0 of arduino or mega. 

void setup()
{
  Serial.begin(9600); 
}

void loop()
{
  int  ffsdata = analogRead(ffs1);
  float vout = (ffsdata * 5.0) / 1024.0; 
  vout *= cf; 

  Serial.print("Flexi Force sensor: "); 
  Serial.print(vout, 3); 
  Serial.println(""); 
  delay(100); 
}

How are the other FSRs connected?
What did you try?

[johnwasser]

@sp817

int ffs1 = A0; // FlexiForce sensor is connected analog pin A0 of arduino or mega. 

int ffss[3] = {A0, A1, A2}; // FlexiForce sensors connected to analog pins. 
...
  for (int i=0; i<3; i++)
  {
     ffsdata = analogRead(ffss[i]);

[sp817]

I have attached an image showing how the first FSR is connected. I have replicated this three times, to attach the other two to the breadboard.
I tried a long-winded way of writing the code out three times.
I will try the altered code and add the arrays in.
Thank you.

[J-M-L]

or with a range based for loop

const float calibrationFactor = 19.5; // calibration factor
const byte flexiForceSensorPins[] = {A0, A1, A2};      // FlexiForce sensors are connected to 3 analog pins of arduino or mega.

void setup() {
  Serial.begin(9600);
}

void loop() {
  for (auto &ff : flexiForceSensorPins) {
    float vout = (analogRead(ff) * 5.0) / 1023.0;
    Serial.print(vout * calibrationFactor, 3); Serial.write('\t');
  }
  Serial.println();
  delay(100);
}

[sp817]

I have just tried this now, but there are errors, showing it's an undeclared identifier.

[anon73444976]

@sp817

but there are errors, showing it's an undeclared identifier.

We can't see your code or your error.

[sp817]

Apologies, my laptop has just crashed, so I will reboot and upload the code shortly. thankyou

[sp817]

Thank you for the code alterations. It wasn't working because I am using an ESP32 board and needed to change the output pins.
I have attached the code, and the corresponding serial output.

const float calibrationFactor = 19.5; // calibration factor
const byte flexiForceSensorPins[] = {A0, A3, A6};      // FlexiForce sensors are connected to 3 analog pins of arduino or mega.

void setup() {
  Serial.begin(9600);
}

void loop() {
  for (auto &ff : flexiForceSensorPins) {
    float vout = (analogRead(ff) * 5.0) / 1023.0;
    Serial.print(vout * calibrationFactor, 3); Serial.write('\t');
  }
  Serial.println();
  delay(100);
}

[J-M-L]

Have fun !

[sp817]

After reviewing the results and doing some further testing, I've noticed some problems.

When the 1st FSR is pressed it is accurate but it also triggers a display from the second.

When the 2nd is pressed, it only registers for the highest value of around 390.

The 3rd FSR is accurate and works well.

[johnwasser]

@sp817

When the 1st FSR is pressed it is accurate but it also triggers a display from the second.

When the 2nd is pressed, it only registers for the highest value of around 390.

Sounds like there may be a wiring problem. Double-check that everything is wired to the right pins. Try swapping pins between two FSR's to see if the problem moves (FSR problem) or stays the same (pin problem).

[sp817]

I agree that its wiring, but I'm unsure of how to change this. I've attached a photo of how this is currently held together on my breadboard. It uses the concept above where a potentiometer is used to customise the sensitivity. Thanks

[sp817]

I swapped around sensors, and wire connections and had the same issues. Where the first FSR displays and output for 1 and 2.
And pressing the 2nd always gives a maxed out value

[johnwasser]

I see the problem.

Look at your solderless breadboard. Look at the red and blue lines down the power busses. See the gaps in the red and blue lines? That is a gap in the power busses. You need jumpers across that gap if you want to have power on both ends of the breadboard.

[groundFungus]

To add to what @johnwasser posted, jumper the gaps like as shown in the (crude) black squares:

[sp817]

Hi guys, after soldering onto a PCB, the connection issues are fixed. And I get accurate responses from the sensors!

I have another piece of code for an air pump. How would I able to activate this code, if an FSR showed an output value of 200?

Thanks