Adding a LCD1602 to barcode scanner set up on UNO (Genuine-R3)

[MeisamKoohaki]

Hi everyone,

I am working on a barcode scanner project with UNO (Genuino-R3) to show the barcode numbers on the LCD1602.

I set up the scanner in this way:

5V -------- 200 k Ω ----- Data
5V -------- 200 k Ω ----- Clock
5V ------------------------- 5V
GND ---------------------- GND

and add the LCD1602 the same this:

LCD1602 UNO Arduino

---

VSS ------------------------>GND
VDD------------------------>+5V
VO ------------------------>10K Potentiometer
RS ------------------------>D12
RW ------------------------>GND
E ------------------------>D11
D0 ------------------------>null
D1 ------------------------>null
D2 ------------------------>null
D3 ------------------------>null
D4 ------------------------>D5
D5 ------------------------>D4
D6 ------------------------>D3
D7 ------------------------>D2
A ------------------------>220/330Ω
K ------------------------>GND

Then LCD works but Scanner work just onetime after each time uploading and dies, I guessed the power is not enough for both, then use separate power for the LCD. For this, I used a Power Supply Module, connect an adaptor 6V and got the 5V. But stay connected

RS ------------------------>D12
E ------------------------>D11

D6 ------------------------>D3
D7 ------------------------>D2

to LCD gets the information too. I want to make sure the hardware is ok, then work on the code.

[6v6gt]

A link to the data sheet of the scanner would be good.
Your code and a wiring diagram would also be good.
I guess it is an I2C device in which case the SDA/SCL line external pullup resistors at 200k are far too high if it has no inbuilt pullup resistors. Try 10k or even 4.7k.