2x16 LCD goes blank when 4 port spdt relay on i2c port

Products & Technology Grove
#1

Hoping someone can help me determine an issue I am experiencing.

When I plugin a grove 4 port SPDT relay to a i2c port my 2x16 LCD goes blank the first row show very faintly black square boxes



When I unplug the relay and reboot the arduino everything works fine.



I am trying to create a project to control turn on a dehumidifier if the room gets too humid, and 2 separate fans if the room gets too hot.



Current Setup

Aruduino Uno

Grove Hat

Temperature / Humidity Sensor (pro)

2x16 LCD on i2c port

4 port spdt relay on i2c port

power 9v battery



Any advice or documents you can forward me to would be greatly appreciated.

#2

Hi there.



please remove these lines(use to change the device i2c address), it reads the i2c device address, if we plug one more i2c device, the code will detect 2 address and stop at this line.



/* Scan I2C device detect device address /

uint8_t old_address = relay.scanI2CDevice() ;

if((0x00 == old_address) || (0xff == old_address)) {

while(1);

}



Serial.println(“Start write address”);

relay.changeI2CAddress(old_address, 0x11); / Set I2C address and save to Flash */

Serial.println(“End write address”);





I also attached my code for lcd and spdt relay.

[code]#include <multi_channel_relay.h>

Multi_Channel_Relay relay;

#include <Wire.h>
#include “rgb_lcd.h”

rgb_lcd lcd;

const int colorR = 255;
const int colorG = 0;
const int colorB = 0;

void setup()
{
lcd.begin(16, 2);

lcd.setRGB(colorR, colorG, colorB);

// Print a message to the LCD.
lcd.print("hello, world!");

Serial.begin(9600);
while(!Serial);

/* Scan I2C device detect device address */
/*uint8_t old_address = relay.scanI2CDevice();
if((0x00 == old_address) || (0xff == old_address)) {
while(1);
}

Serial.println(“Start write address”);
relay.changeI2CAddress(old_address, 0x11);
Serial.println(“End write address”); */

/* Read firmware version */
Serial.print("firmware version: ");
Serial.print(“0x”);
Serial.print(relay.getFirmwareVersion(), HEX);
Serial.println();
}

void loop()
{

/**

  • channle: 8 7 6 5 4 3 2 1
  • state: 0b00000000 -> 0x00 (all off)
  • state: 0b11111111 -> 0xff (all on)
    */

/* Begin Controlling Relay */
Serial.println(“Channel 1 on”);
relay.turn_on_channel(1);
delay(500);
Serial.println(“Channel 2 on”);
relay.turn_off_channel(1);
relay.turn_on_channel(2);
delay(500);
Serial.println(“Channel 3 on”);
relay.turn_off_channel(2);
relay.turn_on_channel(3);
delay(500);
Serial.println(“Channel 4 on”);
relay.turn_off_channel(3);
relay.turn_on_channel(4);
delay(500);
relay.turn_off_channel(4);

relay.channelCtrl(CHANNLE1_BIT |
CHANNLE2_BIT |
CHANNLE3_BIT |
CHANNLE4_BIT);
Serial.print("Turn all channels on, State: ");
Serial.println(relay.getChannelState(), BIN);

delay(2000);

relay.channelCtrl(CHANNLE1_BIT |
CHANNLE3_BIT);
Serial.print("Turn 1 3 channels on, State: ");
Serial.println(relay.getChannelState(), BIN);

delay(2000);

relay.channelCtrl(CHANNLE2_BIT |
CHANNLE4_BIT);
Serial.print("Turn 2 4 channels on, State: ");
Serial.println(relay.getChannelState(), BIN);

delay(2000);

relay.channelCtrl(0);
Serial.print("Turn off all channels, State: ");
Serial.println(relay.getChannelState(), BIN);

delay(2000);
}[/code]

#3

Thank you, your solution worked!