LCD I2C not working

Other Hardware Displays
1

Hello my LCD stopped displaying texts I don't know what is the problem
note: it used to work 2 days ago just fine
I even tried adjusting the little things on the backpack back but with no results, i just get brighter and lighter squares
I even tried to change the wires but still not working

the I2C backpack is well soldered to the LCD

20210627_143557
20210627_1435573096×4128 1.89 MB

and when I run the hd44780 diagnostic I get :

Serial Initialized

I2CexpDiag - i2c LCD i/o expander backpack diagnostic tool

hd44780 lib version: 1.3.2

Reported Arduino Revision: 1.8.13
CPU ARCH: AVR - F_CPU: 16000000

SDA digital pin: 18 A4
SCL digital pin: 19 A5

Checking for required external I2C pull-up on SDA - YES
Checking for required external I2C pull-up on SCL - NO
Checking for I2C pins shorted together - Not Shorted

WARNING: I2C requires external pullups for proper operation
It may appear to work without them, but may be unreliable and slower
Do not be surprised if it fails to work correctly
Install external pullup resistors to ensure proper I2C operation

Scanning i2c bus for devices..
Total I2C devices found: 0
No I2C devices found

2

Did you check?

3

Since the pullup resistor is on the I2C backpack (on most backpacks) I would say that the SCL line has become disconnected or the wire has broken.

4

The solder on the connecter looks questionable, particularly on the VSS pin.

5

That is certainly what the diagnostic is telling you.

There's a bad wire somewhere. Let's see your whole setup.

That's right.

Once you are getting the "blocks" on the first line, you have the contrast more-or-less correct, so clearly that is nothing to do with the problem.

6

Hmmm. Interesting case. I do agree that it looks like there is an issue with the connection/wire on the SCL pin.

I guess I should update the diagnostic sketch to output something about a possible connection issue or broken wire if it "sees" a pullup on one signal but not the other.
That will go on the "to do" list for an update to the diagnostic sketch.

--- bill

7

WhatsApp Image 2021-06-27 at 21.09.20
WhatsApp Image 2021-06-27 at 21.09.20986×1280 117 KB

WhatsApp Image 2021-06-27 at 21.09.20 (1)
WhatsApp Image 2021-06-27 at 21.09.20 (1)1280×1041 180 KB

8

i tried changing wires for the SCL but its not working

9

Actually, I found what may cause the problem,
It is the wiring that is not functioning well as if I change the wires for the SCL it starts working

10

So, it was the broken/ damaged wire, but the first one you swapped in was no better?

Sadly, it may be a good idea to test wires before you use them. :astonished:

11

I did I just think they became not functionally over the course of time.