No i2c address found for 20x4 display

-

hello all, trying 20x4 display working purchased here. uses i2c interface, first order of business find correct i2c address. used sketch found here. 

i made following connections:
(uno -> display)
5v -> vcc
gnd -> gnd
a4 -> sda
a5 -> scl

the scanner sketch unable find i2c addresses. i'm pretty sure have set properly, have checked wiring 100 times , tried several different versions of i2c scanner sketch.

any ideas try screen interface?

 

3 common mistakes when starting i2c
- swapping sda , scl lines
- using digital pins 4 , 5 when should use analog pins 4 , 5
- no pull resistors

all ever want know i2c can found here - http://www.gammon.com.au/forum/?id=10896 -



Arduino Forum > Using Arduino > Displays > No i2c address found for 20x4 display


arduino

Comments

Post a Comment

Popular posts from this blog

invalid use of void expresion in FlexiTimer2 library

-
Image
hello, first post asking in forum patient if dont correctly   well, im trying make robot evades obstacles , uses interrupts in order distances. ive used flexitimer2 run void function each 5ms, problem whe try verify program says me there error in use of flexitimer.    code: [select] flexitimer2::set(1, 1.0/1000, rastreodistanciamin()); i copy code below, please can tell error , how solve it, ive been loking dont know do. thank you code: [select] #include <flexitimer2.h> #include <servo.h> //motor a int ena = 7; int in1=6; int in2 = 5; //motor b int in3=11; int in4=10; int enb=9; servo cabeza; //hc-sr04 device int echo = 13; int triger = 12; //it use hc-sr04 determine , return distance in front of him int calculodistancia(){   volatile int tiempo;   volatile int distancia;   digitalwrite(triger,low); /* por cuestión de estabilización del sensor*/   delaymicroseconds(5);   digitalwrite(triger, high); /* envío del pulso ultrasónico*/   delaymicroseconds(10);   tiem
Read more

error: a function-definition is not allowed here before '{' token

-
i'm new member. me pls code: [select] void manhinh1(){                              tempc = analogread(adc);   tempc = tempc * 0.48828125;                                          lcd.setcursor(0, 0); lcd.print("nhiet: ");                                      lcd.setcursor(7, 0); lcd.print(tempc);   lcd.setcursor(13,0); lcd.print((char)223);    lcd.setcursor(14,0); lcd.print("c");   if(max > min){     if (tempc > max)            {digitalwrite(fan, low);           lcd.setcursor(2, 1); lcd.print("lam mat.....");}     else if (tempc < min)           {digitalwrite(hot, low);           lcd.setcursor(2, 1); lcd.print("dang suoi...");           delay(10000); }     else if (tempc > min && tempc < max)           {digitalwrite(fan, high);            digitalwrite(hot, high);            lcd.setcursor(2, 1); lcd.print("on dinh!!");}              }    else if (max < min){    lcd.setcursor(0, 1);               
Read more

LED Strip Code

-
i downloaded code. here have several single leds flashing music microphone. in project, instead of single rgb leds, have 5 rgb led strips. need change in code? led strip 10m supernight rgb strip cut 5 equal strips. // arduino pin numbers const int do_pin = 2; const int ao_pin = 0; int sound; int led1 = 8; int led2 = 9; int led3 = 10; int led4 = 11; int led5 = 12;   void setup() {   pinmode(do_pin, input);   pinmode(led1, output);   pinmode(led2, output);   pinmode(led3, output);   pinmode(led4, output);   pinmode(led5, output);   serial.begin(9600); }   void loop() {     if (sound > 31) {     digitalwrite(led1, high);   }     if (sound < 31) {     digitalwrite(led1, low);   }     if (sound > 35) {     digitalwrite(led2, high);   }     if (sound < 35) {     digitalwrite(led2, low);   }     if (sound > 40) {     digitalwrite(led3, high);   }     if (sound < 40) {     digitalwrite(led3, low);   }     if (sound > 45) {     digitalwrite(led4, high);   }     if
Read more