You just have to do that for both sensors and use another counter (I see j being defined but not being used so I assume…)Īt every loop you can display these on the screen and subtract them to find the difference and display that number. You have the right idea there with the counter (i) being incremented after each lightPin detect.

Plus right after reading that pin you turn around and write to it without redefining it as an output. Its a little tough to tell what you are trying to do, there is a call to test LEDPin (13) but there is nothing connected to it in the diagram. In a pinch an LED is also a light detector (they love small laser beam points) But you have to get one that will detect the frequency of the laser Or get a opto detector built for laser light. If the problem is that the beam is too small be to be seen by the sensor, you may have to put some diffusion material or a diffraction grating over the sensor to spread that beam out at bit. Second thing is that weedpharma is right - lasers by their nature are one frequency of light, and that frequency may not be detectable (or not very well detectable) by the photo resistor - check the sensors data sheet and see if the the frequency falls within its spectral sensitivity. Without the resistors it may trip all on it’s own at a threshold of 85. This will change your threshold value but it will be much more stable. This will help stabilize the signals you get from the sensors. A 10k 1/4 watt resistor that goes from each pin to ground. Serial.begin(9600) //Begin serial communcationĭigitalWrite(dirpin, LOW) // Set the direction.įirst thing, I would put a dropping resistor on the analog pins that the photoresistors are connected to. Lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE) // init the backlight Int threshold = 85 //intensity of light that triggers the count

Int lightPin = 0 //define a pin for Photo resistor LiquidCrystal_I2C lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin) #define I2C_ADDR 0x27 // Define I2C Address where the PCF8574A is I’m totaly new to Arduino ,so i really need help with the coding because i’m new to it. Second which is i don’t know how to code it after i count it i want to sum the first one alone and the second one alone and see the less the display it on the LCD screen. Which is pointing a laser on the photoresistor and if an object came and cut it it will count +1 and I will also use another photo resistor because i’m using two roads. So I did my best and redo the wiring and the LCD worked with me perfectly with the 'hello world 'code,īut I don’t need this code i tried to take many codes to make my idea work …

Photoresistor circuit arduino