Wio LTE (4G) / I2C_LED Display

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Joined: Mon Jun 25, 2018 3:34 pm

Wio LTE (4G) / I2C_LED Display

Post by p.euerle » Thu Jul 19, 2018 9:59 pm


I want to get the I2C_LED Display working with the Wio LTE 4G Cat.1 (EU version). According to the specifications this should be possible, even if the standard libraries do not directly support the board.

I am a total newbie when in comes to program with Arduino IDE and Grove products, just as I have no knowledge about using the I2C interface. Therefore I'm glad about any help or tips how to get this running.

What I have done / tried so far:
  • set up the driver etc. for Windows 10 like described here and here
  • flashed the Wio LTE board to the latest firmware v1.99 like described here
  • set up the Arduino development environment like described here
Played a little bit with the example sketches (battery status, send sms etc.) - so far everything works well.

After that i connected the I2C_LED Display with the Grove cable to the I2C pin on the Wio LTE board and loaded the example libraries for the display from https://github.com/SparkingStudio/I2C_L ... /resources and loaded the HelloWorld example into Ardunino IDE.

To set up power for the I2C port I also incuded the <WioLTEforArduino.h>, initialized it within the void setup procedure and set the power to ON with Wio.PowerSupplyGrove(true); as you can see in the code:

Code: Select all

#include <Wire.h>
#include <I2C_LCD.h>
#include <WioLTEforArduino.h>
WioLTE Wio;
uint8_t I2C_LCD_ADDRESS = 0x51; //Device address configuration, the default value is 0x51.

//For detials of the function useage, please refer to "I2C_LCD User Manual". 
//You can download the "I2C_LCD User Manual" from I2C_LCD WIKI page: http://www.seeedstudio.com/wiki/I2C_LCD

void setup(void)
    SerialUSB.println("### I/O Initialize.");
    SerialUSB.println("### Power supply ON.");
    Wire.begin();         //I2C controller initialization.

    SerialUSB.println("### Setup completed.");

void loop(void)
    SerialUSB.println("# debug 1");
    LCD.CleanAll(WHITE);    //Clean the screen with black or white.
    delay(1000);            //Delay for 1s.

    SerialUSB.println("# debug 2");
    //8*16 font size auto new line black character on white back ground.
    LCD.FontModeConf(Font_6x8, FM_ANL_AAA, BLACK_BAC); 

    SerialUSB.println("# debug 3");
    LCD.CharGotoXY(0,0);       //Set the start coordinate.
    LCD.print("Hello World!");  //Display "Hello World!" on coordinate of (0, 10).

    while(1);//Wait for ever. 
The sketch compiles without errors and after uploading it and resetting the board i have the following output on the serial monitor:

Code: Select all

### I/O Initialize.
### Power supply ON.
### Setup completed.
# debug 1
# debug 2
# debug 3
But nothing on the display.

I have checked if the I2C interface even gets powered up by measuring the GND an 5V pins on the display and i get 3.3V of current which i think means that this can't be the problem. Next thought was about the definition of the I2C-address (line 6 in the code):

Code: Select all

uint8_t I2C_LCD_ADDRESS = 0x51; //Device address configuration, the default value is 0x51.
can someone confirm that this is correct?

Otherwise I have no idea how to continue - will be thankful for any help provided :)

Best regards

Posts: 2
Joined: Mon Jun 25, 2018 3:34 pm

Re: Wio LTE (4G) / I2C_LED Display

Post by p.euerle » Fri Jul 20, 2018 2:49 am

So, got it running after reading up a little bit about all this I2C stuff:


The Wio LTE board delivers like I mentioned before 3.3V on the I2C bus, but the I2C_LED display needs at least something about 4.5V to 5V to function.


I cut the red and black wires on the Grove cable, connected the red wire which leads to the display to the positive connector on an external power source with 4.5V.

Important: make sure that it is the red wire which is connected to the display and not the one which is connected to the Wio LTE board. Otherwise this may kill the board.

Then I connected the black wire which comes from the Wio LTE board, the black wire which leads to the display to the negative of the external power source.

That's it - the sketch posted above runs perfectly fine and the display shows "Hello World!".

Posts: 200
Joined: Tue Apr 17, 2018 11:03 am

Re: Wio LTE (4G) / I2C_LED Display

Post by hong.jiang » Fri Jul 20, 2018 9:01 am

Hi, thanks for the sharing. The wio lte Grove interfaces power with 3.3v. If we use any 5v devices(such as rgb lcd), we have to use the external power supply. we also have to share the GND between external power supply/wio lte/grove modules. thanks.

Seeed techsupport team

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