How to analogRead() 2 separate pins simultanously?

Question

I am trying to create a simple piano playback using a flex sensor, a proximity sensor and a piezo buzzer.

I want to have it so that when the flex sensor is triggered, a sound is played on the piezo buzzer. The tone it makes is dependent on the values received from the proximity sensor.

Here is my code:

int psrAnalogPin = 6;
int fsrAnalogPin = 10;
int speaker = 9;
int fsrReading; 
int psrReading; 
void setup(void) {
 Serial.begin(9600);
 // We'll send debugging information via the Serial monitor
 pinMode(speaker, OUTPUT);
}
void loop(void) {
 psrReading = analogRead(6);
 delay(10);
 psrReading = analogRead(6);
 delay(10);
 Serial.print("\n psr reading = ");
 Serial.println(psrReading);
 fsrReading = analogRead(10);
 delay(10);
 fsrReading = analogRead(10);
 delay(10);
 Serial.print("\n fsr reading : ");
 Serial.println(fsrReading);
 if(fsrReading < 980 && psrReading > 599){
 tone(9, 400, 1000);
 } else if (fsrReading < 980 && psrReading > 500){
 tone(9, 500, 1000);
 } else if (fsrReading < 980 && psrReading < 392){
 tone(9, 600, 1000);
 }
}

When I look at the serial monitor's output, the values output seem to be only reading from my flex sensor(fsrReading) and not my proximity sensor. If I only read the proximity sensor's value it works, but not both at the same time.

How can I get it so that it reads both values instead of just one?

• Mikael Patel: Which board are you using?
• Edgar Bonet: You cannot take two analog readings simultaneously, but you can take them one after the other, just like you did. That being said, I see nothing wrong in your code. Are you sure you have no wiring problems?

Answer 1

This is not a full code but more of an explanation of the logic of your program.

when the flex sensor is triggered, a sound is played on the piezzo buzzer. The tone it makes is dependent the values received from the proximity sensor.

Follow this logic and try to code it:

1- read the flex sensor values

int val = analogRead(flexPin);

2- if it is triggered, THEN read the proximity sensor.

if(val > minimum) {
 int distance = analogRead(proximityPin); //this line depends on which proximity sensor you are using

3- play the sound accordingly to the proximity sensor (still in the if loop).

analogWrite(distance);

This logic should work fine. If you could include more info like board, flex sensor and proximity sensor, that could help.

Answer 2

You can try using Interrupts instead of polling the sensor values, as interrupt will only be activated during rising-edge or falling edge. More info on interrupts:

• http://playground.arduino.cc/Code/Interrupts
• https://gonium.net/md/2006/12/20/handling-external-interrupts-with-arduino/