Change address for LCD I2C?

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ApoAda
 
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Change address for LCD I2C?

Post by ApoAda »

I have been trying to run the "Hello World" I2C script using an Arduino Uno with a 1602 LCD with I2C backpack, but haven't been able to see any characters displayed. I've tried the Adadruit_LiquidCrystal library (amongst others) to no avail. I attempted to adjust the potentiometer, but no characters are visible regardless of the position of the pot. I ran an I2C scanner script and it reported an I2C device at 0x3F. The Adafruit_LiquidCrystal lcd() command doesn't appear to be able to designate this particular address, so I tried to add a "#define I2C_ADDR 0x3F" command prior to the setup(), but that didn't help either. The LCD and I2C backpack I'm using came pre-assembled and all the connections appear okay. I've ordered an LCD and I2C backpack from Adafruit, but was hoping to troubleshoot what I have while waiting for the new display to be delivered. Any suggestions?

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dastels
 
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Re: Change address for LCD I2C?

Post by dastels »

What exactly is the "1602 LCD with I2C backpack"?

Dave

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ApoAda
 
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Re: Change address for LCD I2C?

Post by ApoAda »

HiLetgo HD44780 IIC I2C1602 LCD Display with IIC I2C TWI SPI Serial Interface Adapter 1602 LCD Display Blue Backlight for Arduino

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dastels
 
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Re: Change address for LCD I2C?

Post by dastels »

There's no reason to expect an Adafruit library to function as expected with non-Adafruit hardware. Go to the manufacturer/vendor for technical support and/or documentation. We're happy and able to help with the Adafruit products.

Dave

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ApoAda
 
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Re: Change address for LCD I2C?

Post by ApoAda »

Thanks Dave, I agree that there was no guarantee that an Adafruit library would function on non-Adafruit hardware, however, others have commented in different forums that Adafruit library code is written extremely well and often functions regardless of the hardware manufacturer/vendor; so, I thought it was worth a try. In addition to ordering a display/backpack from Adafruit to try I have also contacted the manufacturer of the hardware I'm trying to troubleshoot, so I am exploring all avenues to see if I can address this issue. If nothing else, each time I have to troubleshoot a problem I tend to learn a lot [which is really not saying much considering my knowledge deficit :) ].

Randy

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dastels
 
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Re: Change address for LCD I2C?

Post by dastels »

I expect the library will work, but it will be working in the dark with some documentation on the display.

Dave

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ApoAda
 
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Re: Change address for LCD I2C?

Post by ApoAda »

I finally got the display to work with the LiquidCrystal_I2C.h library by using the 0x3F address as reported by the I2C Scanner in the lcd(0x3F, 16, 2) command. I'm not sure why this didn't work before.

I had tried to poke around and see if I could declare this address using the Adafruict_LiquidCrystal library, but couldn't see any way to declare a different address in the script and wasn't sure about soldering any of the pins A0-A2 to achieve this address.

Anyway, I seem to be moving forward . . .

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