Using Multiple i2c lcd(1602) with ESP8266

Other Hardware Displays
1

I want to use 2 i2c lcds with one ESP8266
But, They have same address.
I want to show different texts on multiple ic2 lcd.
Please help me.

Thanks.
Js.

2

All I2C backpacks have configurable slave addresses. e.g. A0, A1, A2 solder pads.
Ensure that you have different addresses for each LCD.

3

david_prentice:
All I2C backpacks have configurable slave addresses. e.g. A0, A1, A2 solder pads.
Ensure that you have different addresses for each LCD.

So that means i can't change address without soldering?
Thanks.

4

Yes, you require a soldering iron.

Post a link to the actual backpack. You might be able to stick a piece of wire across two holes on some backpacks.

I suggest that you buy another LCD + backpack. Make sure that one is PCF8574 and the other is PCF8574A.

David.

5

hellojsna:
So that means i can't change address without soldering?

There is very little you can do in electronics without soldering.

Yes, you can play with a few basic experiment with Arduinox, but basically nothing serious.

That said, you should not necessarily have to have the equipment yourself, even in Korea (or perhaps, especially in Korea! :grinning: ). You should be able to find a "maker" facility/ club somewhere, if not a neighbour with equipment and skills, to help you.

6

Paul__B:
There is very little you can do in electronics without soldering.

Yes, you can play with a few basic experiment with Arduinox, but basically nothing serious.

That said, you should not necessarily have to have the equipment yourself, even in Korea (or perhaps, especially in Korea! :grinning: ). You should be able to find a "maker" facility/ club somewhere, if not a neighbour with equipment and skills, to help you.

I finished soldering and it works (0x27, 0x23). But I can't see characters in one lcd, the other one works fine :). I think the voltage is too high.

480×640 79.2 KB

(Image link changed)
Is there any ways to reduce output voltage?
Thanks.
Js.

7

On the back of the Blue LCD backpack you will see a small blue square potentiometer with a screwdriver adjustment.

As you turn the screwdriver the contrast will look better or worse.
Most show the best contrast when turned fully clockwise.

Repeat the adjustment with the Green LCD.

David.

8

david_prentice:
On the back of the Blue LCD backpack you will see a small blue square potentiometer with a screwdriver adjustment.

Are you seeing an image in his post? Its URL is http://1.236.79.12:58080/Usercontents/temp/NOEXP/IMG_8637.JPG

9

Not seeing an image in the post above.

Disappeared from my post when I put it in image tags too.

10

Paul__B:
Are you seeing an image in his post? Its URL is http://1.236.79.12:58080/Usercontents/temp/NOEXP/IMG_8637.JPG

I think it works fine...

image is under here(NOT from my server)

(Image ends here)

or That image(http://1.236.79.12:58080/Usercontents/temp/NOEXP/IMG_8637.JPG) is hosted on my server in Korea, so it may take a time to download my images from my server.

11

hellojsna:
so it may take a time to download my images from my server.

Which time it seems, may be several hours. :grinning: That explains the unusual URL.

OK, I can see it now. You definitely need to adjust the contrast potentiometer on the blue display - not sure in which direction. Whichever direction it is, you then need to adjust the contrast potentiometer on the green display in the same direction if it uses the same I2C "backpack"