Don't know how to program this particular 4 digits 7 segments

[jojodelapatate]

I got one these 4 digits 7 segments :

After reading the documentation, I don't know how to handle the code...
it's not a usual 4-digit display with CLK DIO VCC GND pins but with GND SCK SDI RX 5V pins and I don't know how to program it.
Could somebody help me ?
Cheers

[J-M-L]

The doc is pretty clear

I2C or UART based communication and you send a one byte payload as described (so send 4 bytes to set the 4 digits).

If you look at their picture

The wire coming from the back seems to be connected to pin 1 of the UNO which is the Serial Tx pin, likely connected to the Rx pin. So sending the byte is just a matter of a Serial.write(). The other 2 wires are likely 5V and GND. They did not use the I2C pins.

I believe they would use likely 115200 bauds as it would make sense to not go too slow but it might be 9600 or autobaudibg maybe ?

So if you wire as they did and run this

void setup() {
  Serial.begin(115200); // 115200 bauds - try 9600 if it does not work 
  Serial.write(0x79); // -
  Serial.write(0x23); // 3
  Serial.write(0x82); // .
  Serial.write(0x11); // 1
  Serial.write(0x04); // 4
}

void loop() {}

You should see as they say in the doc -3.14

If not try to change the baud rate to 9600

May be a small delay() is needed if the module is slow to boot up.

[noiasca]

@jojodelapatate

I don't know how to program it

Why bother with something you don't get a working library for?
Send it back and get something with a MAX7219, HT16K33 or TM1637.

For a retail price of 16 EUR for 4 digits, the vendor should care about a library too.

[jojodelapatate]

I work for a public library in France and the process to send back an object is hell... (so I prefer to try to make it work)

[jojodelapatate]

thank you very much for your time. I'll try it.

[gilshultz]

I would configure it as I2C, that requires 4 wires, power, ground, SCL, and SDA.
Operating voltage +5V
Power current
1.2mA typ. (with all LEDs off) 80mA (with all LEDs on)
Interface I2C, Serial TTL
I2C address 0x0C

When you get it connected use the I2C scanner to verify it is at address ox0C. Read the documentation for the wire.h library, from that you should be able to communicate with it.

[J-M-L]

I2C would needs one extra wire and makes the transmission code more verbose as you manage the transmission.

#include <Wire.h>

void setup() {
  Wire.begin();

  Wire.beginTransmission(0x0C);
  Wire.write(0x79); // -
  Wire.endTransmission();

  Wire.beginTransmission(0x0C);
  Wire.write(0x23); // 3
  Wire.endTransmission();

  Wire.beginTransmission(0x0C);
  Wire.write(0x82); // .
  Wire.endTransmission();

  Wire.beginTransmission(0x0C);
  Wire.write(0x11); // 1
  Wire.endTransmission();

  Wire.beginTransmission(0x0C);
  Wire.write(0x04); // 4
  Wire.endTransmission();
}

void loop() {}

Of course this could be wrapped into a function but I find the Serial interface more straightforward (and a bit faster at 115200 bauds than I2C default 100kHz)