B4R Question problem about I2C LCD display

vali khandangoll

Active Member
hi all of you.
I have a I2C lcd display.
I use rLiquidCrystal_I2C version 1.01 in B4R project like below

lcd.Initialize(0x27, 16,2)
lcd.Backlight=True
lcd.Write("test")

Delay(5000)
lcd.Backlight=False

my lcd backlight was currectly but dont show any text.
 

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Mark Read

Well-Known Member
Licensed User
Longtime User
A few thoughts:

1. Have you tried setting the cursor before writing?

B4X:
Private Sub AppStart
    Serial1.Initialize(115200)
    Log("AppStart")
    
    lcd.Initialize(0x27, 16, 2) 'based on the example from the project.
    '   lcd.Initialize(0x27, 20, 4) ' for 20X4 lcd
    lcd.Backlight = True
    lcd.SetCursor(0,0)
    lcd.Write ("Row 1")
     lcd.SetCursor(0,1)
    lcd.Write("Test") 
 
End Sub

2. Have you tried changing the contrast poti on the i2c board? Even without a program running you should be able to see the block top left.
3. Try the address 0x3f instead of 0x27.
4. Check the address with an I2C scanner: Link
 
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vali khandangoll

Active Member
A few thoughts:

1. Have you tried setting the cursor before writing?

B4X:
Private Sub AppStart
    Serial1.Initialize(115200)
    Log("AppStart")
   
    lcd.Initialize(0x27, 16, 2) 'based on the example from the project.
    '   lcd.Initialize(0x27, 20, 4) ' for 20X4 lcd
    lcd.Backlight = True
    lcd.SetCursor(0,0)
    lcd.Write ("Row 1")
     lcd.SetCursor(0,1)
    lcd.Write("Test")
 
End Sub

2. Have you tried changing the contrast poti on the i2c board? Even without a program running you should be able to see the block top left.
3. Try the address 0x3f instead of 0x27.
4. Check the address with an I2C scanner: Link

thanks for your answer.
I think my lcd in damage.
 
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