Whenever I use the project, I get large outliers, like 2000 cm+. This happens in between while i am moving and the next value that is recieved.
/*
* This ESP8266 NodeMCU code was developed by newbiely.com
*
* This ESP8266 NodeMCU code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/esp8266/esp8266-ultrasonic-sensor-lcd
*/
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27 (from DIYables LCD), 16 column and 2 rows
#define TRIG_PIN D5 // The ESP8266 pin connected to Ultrasonic Sensor's TRIG pin
#define ECHO_PIN D7 // The ESP8266 pin connected to Ultrasonic Sensor's ECHO pin
float duration_us, distance_cm;
void setup() {
lcd.init(); // Initialize the LCD I2C display
lcd.backlight(); // open the backlight
pinMode(TRIG_PIN, OUTPUT); // config trigger pin to output mode
pinMode(ECHO_PIN, INPUT); // config echo pin to input mode
}
void loop() {
// Produce a 10-microsecond pulse to the TRIG pin.
digitalWrite(TRIG_PIN, HIGH);
delayMicroseconds(10);
digitalWrite(TRIG_PIN, LOW);
// Measure the pulse duration from the ECHO pin
duration_us = pulseIn(ECHO_PIN, HIGH);
// calculate the distance
distance_cm = 0.017 * duration_us;
lcd.clear();
lcd.setCursor(0, 0); // start to print at the first row
lcd.print("Distance: ");
lcd.print(distance_cm);
delay(500);
}
ignore the value if it's too different from the previous one and make a note that you ignored a value (and after ignoring N values in a row, consider it might be right and go for it)
If the device only collects data when a button or trigger is pressed or if it stops collecting when a button or trigger is pressed
then a button or trigger would control data collection one way or the other.
Then when you want to move the device you would make it stop collecting. I would go with collecting when triggered, point and trigger to get data and let up before moving it. But the other way it would need a press before moving and start collecting when let up. Either way you control when data is collected... hold the button to stop works when you want to walk away and still collect but if press means collect you can set it down and not collect.
That's two ways to cover two ways to use the device with only one button or trigger. Those aren't the only ways but they are the most simple... a double-click could make it work opposite for example. I think that I'd want a led that blinks whenever the device is collecting, the blink showing that the code isn't stuck.
This isn't specific to Arduino, it is user interface technique used in devices and computers going back over 50+ years!
delete the highest two and lowest two
4 Average the remaining data.
This works because any averaging of a over range reading will skew the data. My suggestion simply deletes the out of range numbers, without having to "test" each value for out of range.
