Hi I have an 1621 lcd .
On the pads i can read

How can I connect it to arduino uno and what's a test code?
Thank you

will probably need more info about the unit ,who made it that kinda thing and many of your lables correspond to the normal pinouts after that you will probably have to investigate the specific type for the finish details.

I have not idea who make this unit. I grab it from a money counter and I think is quite a serial unit

Unless you can post a clear photograph of the device you are unlikely to get much help.

Please try again using a different translation program.


Try this scan

lcd.pdf (76.7 KB)

I wouldn't call that 'clear'.


@floresta : modified

The problem is that i have not way to make a clear photo.
The writes on are :

No other connectors no other writes.

It is obviously has some sort of serial interface. Here is how I would proceed.

led and led+: These are probably the backlight connections. Connect them to a 5 volt supply with a 150 ohm series resistor and see if the backlight works. If it is very bright then use a larger resistance.

Vss and Vdd: These are probably the power supply connections. Most likely 5 volts but possibly 3.3 volts. Connect them and check for excessive heat.

Vlcd: This is probably what is usually called the 'contrast' pin. Connect it to the wiper of a 10 K potentiometer. Connect the ends of the potentiometer to Vss and Vdd. You should see a blank screen with the wiper adjusted to give 5 volts and a lot of 'blocks' with the wiper adjusted to give 0 volts. You want a single row of blocks to be visible, but not too dark.

If your LCD is giving you the row of blocks you can now start tinkering with the serial interface. It could be I2C, SPI, or a TTL version of standard RS-232.

/cs: Chip select.
/wr: Read/Write. You probably want this low since you will be writing to the LCD.


right for backlight
If i connect vss and vdd and no other pins nothing is on..The vlcd can be connected with 10k resistor to vss or vdd?
Afther that it will be the rows right?

If i connect vss and vdd and no other pins nothing is on..

That is normal since you have not powered the LCD display.

The vlcd can be connected with 10k resistor to vss or vdd?

You typically use a 10K potentiometer. The outer terminals go to Vdd and Vss and the center goes to Vlcd.
You could try connecting Vlcd directly to Vss - some LCDs work acceptably that way.