COmparing previous variable

Projects Programming
1

Hi, essentially what i am trying to do is take a sensor reading from a tfmini lidar sensor than take another reading from the TFMINI Lidar and compare the 2 readings. The TFmini lidar code looks like this:

#include <Wire.h>
#include <SoftwareSerial.h>
#include "TFMini.h"

SoftwareSerial mySerial(10, 11);

TFMini tfmini;

void setup(){
Serial.begin(115200);

while (!Serial);
Serial.println ("Initializing...");

mySerial.begin(TFMINI_BAUDRATE);

tfmini.begin(&mySerial);

}
void loop(){
mySerial.listen();
if (mySerial.isListening()) {
Serial.println("Port One is listening!");
}else{
Serial.println("Port One is not listening!");
}
uint16_t dist = tfmini.getDistance();
uint16_t strength = tfmini.getRecentSignalStrength();

// Display the measurement
Serial.print(dist);
Serial.print(" cm sigstr: ");
Serial.println(strength);

}

This code simply takes a reading from the Lidar in a loop.

Originally I was trying to save a sensor reading once it was taken in an integer. Than take another reading and compare it to the saved reading. when I gave it a try it proved to be unsuccessful.

Code for that looks like this:

#include <Wire.h>
#include <SoftwareSerial.h>
#include "TFMini.h"

int sensorvalue1 = 0;
int sensorvalue2 = 0;

SoftwareSerial mySerial(10, 11);

TFMini tfmini;

void setup(){
Serial.begin(115200);

while (!Serial);
Serial.println ("Initializing...");

mySerial.begin(TFMINI_BAUDRATE);

tfmini.begin(&mySerial);

}
void loop(){
mySerial.listen();
if (mySerial.isListening()) {
Serial.println("Port One is listening!");
}else{
Serial.println("Port One is not listening!");
}
uint16_t dist = tfmini.getDistance();
uint16_t strength = tfmini.getRecentSignalStrength();

// Display the measurement
Serial.print(dist);
Serial.print(" cm sigstr: ");
Serial.println(strength);
dist = sensorvalue1;

delay(2000);

//run sensor again
uint16_t dist2 = tfmini.getDistance();
uint16_t strength2 = tfmini.getRecentSignalStrength();

// Display the measurement
Serial.print(dist2);
Serial.print(" cm sigstr: ");
Serial.println(strength2);
dist2 = sensorvalue2;

}

than after I got the 2 stored readings I would put an if statement in which if value one was greater than value 2. And an if statemnt
if value 2 is greater than value 1.

Unfortunately it doesn't seem to operate.

Thanks for any help!

2 
  dist = sensorvalue1;

Don't you want that the other way round?

Please remember to use code tags when posting code.

3

So I made some changes and I am successfully able to store readings in a global variable. The problem I am having is that my code isn't running through my full if statement. I have marked where it stops reading in code:

#include <Wire.h>
#include <Adafruit_PWMServoDriver.h>

Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver();
//#define SERVOMIN 105 // this is the 'minimum' pulse length count (out of 4096)
//#define SERVOMAX 515 // this is the 'maximum' pulse length count (out of 4096)
//2.27=1 degree

// our servo # counter
uint8_t servonum = 105;
#include <Wire.h>
#include <SoftwareSerial.h>
#include "TFMini.h"
bool running = false;

SoftwareSerial mySerial(51, 50); // Uno RX (TFMINI TX), Uno TX (TFMINI RX)
SoftwareSerial mySerial2(53, 52);

TFMini tfmini;
TFMini tfmini2;
int s1t1;
int s1t2;
int s2t1;
int s2t2;

void setup() {
Serial.begin(115200);
Serial.println("16 channel Servo test!");

pwm.begin();
pwm.setPWMFreq(60); // Analog servos run at ~60 Hz updates
pwm.setPWM(0, 0, 105);
delay (1000);
pwm.setPWM(1, 0, 105);
delay (1000);

while (!Serial);
Serial.println ("Initializing...");

//Initialize the data rate for the SoftwareSerial port
mySerial2.begin(TFMINI_BAUDRATE);
mySerial.begin(TFMINI_BAUDRATE);

//Initialize the TF Mini sensor
tfmini2.begin(&mySerial2);
tfmini.begin(&mySerial);

}

void loop() {

if (running = false){

mySerial.listen();
delay (2000);

if (mySerial.isListening()) {
Serial.println("Port One is listening!");
}else{
Serial.println("Port One is not listening!");
}

uint16_t dist = tfmini.getDistance();
s1t1=dist;
// uint16_t strength = tfmini.getRecentSignalStrength();

// Display the measurement

Serial.print(s1t1);
Serial.println(" cm");

pwm.setPWM(0, 0, servonum);
delay (1000);

pwm.setPWM(1, 0, servonum);
delay (1000);

// Serial.println(strength);

//delay(2000);

uint16_t dist2 = tfmini.getDistance();
s1t2=dist2;
// uint16_t strength = tfmini.getRecentSignalStrength();

// Display the measurement

Serial.println(dist2);
Serial.println(" cm");

delay (2000);

//*********************************************** arduino doesnt run through these if statements

if ( s1t2 - s1t1 > 20){
running = true;
}
else {

running = false;
servonum = servonum + 2;
}

}

if (running = true){

mySerial2.listen();

delay (2000);
//***********************************************

if (mySerial2.isListening()) {
Serial.println("Port two is listening!");
}else{
Serial.println("Port two is not listening!");
}
uint16_t dist3 = tfmini2.getDistance();
// uint16_t strength3 = tfmini2.getRecentSignalStrength();
s2t1=dist3;

// Display the measurement
Serial.println(dist3);
// Serial.println(strength3);

delay (1000);

if ( s1t2 > s2t1){

Serial.print ("greater");

}

if ( s1t2 < s2t1){

Serial.print ("less");

}

//Serial.println (servonum);

}

}

It also runs through the boolean true loop when boolean is set to false. Vice versa. Thanks

4

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spiderpro2003:
my code isn't running through my full if statement. I have marked where it stops reading in code:

What does the Serial monitor show as the values of slt1 and slt2?

spiderpro2003:
It also runs through the boolean true loop when boolean is set to false.

Please study the difference between = and ==: