D.I.Y SMART RGB MATRIX 8x16

16,728

119

25

About: PLC, Arduino - Do it yourself project

In this project, I’ll show you how to make your own 8×16 RGB LED Matrix using Arduino Uno/ Nano. An LED Matrix can show scrolling messages, display animations, music spectrum analyzer … With integrating NodeMCU, it can be used as small screen to show weather information from internet or any process values when it connect to Ethernet PLC system.

So, let's watch my videos below and follow my instructables to start with building your own RGB LED Matrix.

  • Auto-rotate scrolling message test (update on November 6th, 2018): Using MPU-6050 with Kalman filter to calculate the angle when we rotate Led Matrix.

  • Animation Test

  • VU meter test: It shows music

    volume unit by

    using fix FFT transformation. Led Matrix will be connected to music player by audio jack 3.5mm.

  • Smart Display Test: Connecting to PLC system

  • Smart Display Test: Showing weather information from Internet

Step 1: PARTS LIST & TOOL

Step 2: SHEMATIC DIAGRAM

My RGB matrix panel with 128 x RGB LEDs is arranged in 8 rows and 16 columns, including:

  1. Led Matrix Board: is built on a single-side copper prototype PCB 9x15. With my instructables, Led Matrix can be plugged on top of the Driver Board, like a Shield.
  2. Driver Board: are built on a double-side copper prototype PCB 9x15. Driver Board handle column & row scanning to control Led Matrix Board above.

  • Column scanning: is done through 2x 74HC138 cascading connection to build 4 to 16 line decoder as diagram above. With this combination, it can accept 4 bit binary coded decimal number on its 4 inputs and can select one of its 16 outputs. And then it drive 16 corresponding PNP transistors (A1013).
  • Row scanning: through 3x 74HC595, 3 x ULN2803 for 3 colors: RED, GREEN, BLUE .

To control an individual color of common anode RGB LED, you set its column HIGH and its corresponding color row LOW.

We know that the brightness of a LED can be controlled by switching it on and off very rapidly. To do that, Pulse Width Modulation (PWM) is often chosen by using PWM pins on Arduino, beside that B.A.M is a another method to achieve the same thing.

For B.A.M, you can check at my instructables:

https://www.instructables.com/id/Interactive-Color...

https://www.instructables.com/id/BI-COLORS-MATRIX-...

Please follow next step to see my assembly for Led Matrix Board & Driver Board in detail.

Step 3: BUILD THE MATRIX

There are a lot of ways to solder a led matrix and I will share my tip to do a led matrix like a compact shield from prototype board:

- Decide to purchase RGB Led size & type: For me, I used common anode type with size 5mm. There are a lot of ways to solder a led matrix that final purpose is connecting all anode pins of the LEDs in columns and the cathode pins (pin Red, Green, Blue) in rows.

- Arrange the LEDs in the prototype board in symmetrical form.

- Then, take the R, G, B pins of the first LED in first row and bend it down to the other LEDs and solder the pins which touch each other.

- Do the same with 2nd row until finish 8th row.

- Finish rows of Led matrix and we need to check every led because at this time, it is easy to fix if there are any broken led or any short circuit between the anode/ cathode pins.

- For led matrix column, I also bent the anode pin and connected them like we did with the cathode pins. To get an isolated gap between anode and cathode pins, we padded an ABS Round Plastic Pipe when bending led pin.

- At the vertical & horizontal end of prototype, I connect anode & all R, G, B pins to long pin male header for later connecting to Led driver board.

- Testing RGB led one more time.

- Finish Matrix Board

Step 4: BUILD DRIVER BOARD

Driver Boards, including: column (layer) scanning (74HC138 + Transistor A1013), row scanning (74HC595 + ULN2803) and Arduino Uno/ Nano. Led Matrix is a shield that it can be plugged on top of the Driver Board.

  • Prepare the horizontal & vertical female header at Driver Board. At this time, I also soldered 16 x A1013 transistors with its outputs is aligned with corresponding columns of Led Matrix.

  • Testing whether male header of Led Matrix & female of Driver Board is matching together or not to correct it.

  • Visually checked the contacting between male and female.Well, it is matching together like that.

  • Following schematic below, I installed 3x 74HC595, 3 x ULN2803, 24 x 100Ω Resistors, 3 x 0.1uF Capacitors on prototype board and did soldering work. Each shift register 74HC595 will control one color so we have totally 3 shift registers for handling: Red, Green, Blue colors. Arduino pins assigned for SPI controlling:

- BLANK PIN (ENABLE) -----> 3 (PD2)

- LATCH PIN -----------------> 2 (PD3)

- CLOCK PIN (SCK) ----------> 13

- DATA PIN (MOSI)------------> 11

  • For column circuit, I use 4 signals from Arduino Nano for multiplexing 2 x 74HC138 to control 16 RGB led's columns through 16 x A1013 transistors circuit. It is need to connect 560Ω resistor between pole B of transistor and 74HC138 for polarization. Arduino PORTD pins were used for multiplexing as follows:

- D4 (PD4) connect to A0.

- D5 (PD5) connect to A1.

- D6 (PD6) connect to A2.

- D7 (PD7) connect to A3.

Note: 74HC138 has active low outputs, it means this chip sets the selected pin low and all others high. Below is Truth table for this combination:

Note: Back side of above picture is the 1st version that I test with Arduino Uno with some male headers.

- Soldering DC female jack for power supply and female header for Arduino Nano.

- Installing Arduino Nano on prototype board. I also reserved space for NodeMCU for further future extension. This nodeMCU communicate to Arduino Nano through I2C protocol and it is pre-connected.

- Cleaning the boards, check again all RGB leds on Matrix board, continuity checking with a Multimeter. And then, connecting Led Matrix & Driver Board together. Here is the final results that I achieved.

Step 5: PROGRAMMING & PICTURES

https://github.com/tuenhidiy/Smart-RGB-Matrix

  • Some project pictures:

Step 6: BECOME SMART MATRIX

So, to develop this project, with existing hardware configuration I can make this RGB led matrix smarter through SPI, I2C and Ethernet interfaces.

  • SPI & BAM: Arduino Nano show process values on RGB Matrix.
  • I2C: Arduino Nano comunicate to NodeMCU to get raw values.
  • Ethenet: NodeMCU communicate to PLC (like temperature/ pressure/ flow ... daily production, daily delay and some production KPIs...) or get values from internet, like weather information.

My testing picture with PLC is as below. You can check interface between NodeMCU and PLC S7-300 at my topic:

https://www.instructables.com/id/ARDUINO-HACK-PLC-...

Step 7: BECOME AUTO-ROTATE MATRIX

Soldering MPU-6050 on the Driver Board following schematic above. I used MPU-6050 with Kalman filter to calculate the angle when we rotate Led Matrix. For Kalman Filter library, you can refer at address:

https://github.com/TKJElectronics/KalmanFilter

In my opinion, it works perfectly and accurately when values reading from MPU-6050 is passed through this filter.

Arduino code for Auto-Rotate RGB Matrix on my GitHub:

https://github.com/tuenhidiy/Auto-Rotate-RGB-Matri...

Please pay attention to 2 lines in the subroutine below. After reading values from MPU-6050, AngleX will be in range: -180 to 180 and I based on this to determine text direction showing on Led Matrix.

read_MPU6050();
AND
uint8_t pos = (kalAngleX >0 ? 1:0);
void hScroll_colorwheel_MPU(uint8_t y, Color Bk_color, char *mystring, uint8_t font, uint8_t delaytime, uint8_t dir)
{
  int offset =0;
  Color setcolor, For_color;
for ((dir) ? offset=0 : offset=((lenString(mystring)-8)*8-1) ; (dir) ? offset <((lenString(mystring)-8)*8-1) : offset >0; (dir) ? offset++ : offset--)
  {
    read_MPU6050();
    
      for (byte xx=0; xx<16; xx++)
      {
        for (byte yy=0; yy<8; yy++)
            {
              get_colour(colourPos + 8*(yy+xx), &For_color.red, &For_color.green, &For_color.blue);
              uint8_t pos = (kalAngleX >0 ? 1:0);
              if (pos)
              {
              if (getPixelHString(xx+offset,yy,mystring))              
                setcolor = For_color;             
              else setcolor=Bk_color;
                LED(xx,(yy+y),setcolor.red, setcolor.green, setcolor.blue);
              }
              else
              {
                if (flipbyte(getPixelHString((xx+offset),yy, mystring)))              
                setcolor = For_color;           
                else setcolor=Bk_color;
                LED(15-xx,7-(yy+y),setcolor.red, setcolor.green, setcolor.blue);
              }
            }
        }
        delay(delaytime); 
        increment_colour_pos(2); 
      }

}

My first testing video is as below:

Thank for watching !!!

Optics Contest

This is an entry in the
Optics Contest

Share

    Recommendations

    • Plastics Contest

      Plastics Contest
    • Optics Contest

      Optics Contest
    • Make it Glow Contest 2018

      Make it Glow Contest 2018

    25 Discussions

    0
    None
    Raygem

    Question 9 hours ago

    Hello, I have a question and I've been trying to figure out but not getting any answer that convince me, why are you using transistors if you are already using the ULN? are not the transistors doing the same job? I'm using a RGB matrix with transistors (not using an ULN), working properly, so why use them? Maybe I am wrong or I am avoiding something, thanks a lot.

    0
    None
    Se3ker

    Question 1 day ago

    Hi, can this be chained to form an 8x32 panel? or more by simply adding another 2(hc138)+3(hc595) ??

    1
    None
    tuenhidiyArbormakes

    Reply 9 days ago

    Hi Arbomakes,
    Thank you! I've just entered to "Optics Contest" following your advice.

    0
    None
    mmccoury

    Question 6 days ago on Step 1

    Very nice project. Would you be able to post a picture of the back side of the driver board?

    1 more answer
    0
    None
    tuenhidiymmccoury

    Answer 6 days ago

    Hi
    Thanks ! I've just updated the back side picture of Driver Board on Step 4.
    Note: This back side picture is the 1st version that I tested with Arduino Uno with some male headers.

    0
    None
    LaserDave

    13 days ago

    Nice project, great pictures too!!

    I have just two questions -
    1 - Why not save yourself some headache and extra wiring and use a single 74154 instead of the two 74138?
    2 - You went to all the work laying out your circuitry, why not go the extra step and send out the PCB file to get fabricated boards inexpensively? I know you knocked yourself out with all the LED wiring, the transistors, chips and header wiring, and that is SO time-consuming. It's also very easy to make a mistake that's really tough to track down. Don't you think it would be so sweet to save yourself all that, and simply stuff your components into professionally-made boards? That would take you an evening instead of a week.

    You are probably the type, as I once was, where you are so in love with electronics that you would make your own pencils if you had to... and the hard stuff is part of the fun. Right?

    Great job anyway, however you choose to do it.

    1 reply
    0
    None
    tuenhidiyLaserDave

    Reply 13 days ago

    First of all, thanks for your constructive comment and I would like to answer your two questions:
    1 - The problem is I just use some ICs what I have in my hand, although I know that 74HC154 is easier for 4 to 16 line decoder.
    2 - Every day, I go home late and play with my kids until they go to sleep. After that, this is my time, and I have started to do the things that I want to see final result. Accumulated works will be done day by day because my time is limited, as well as, my job & knowledge is a other field, not electronic. If I do etching PCB, I also do it by myself, as some projects that I posted on Instructables.
    Another thing, when I make my own circuits on PCB prototype, I can customize it or sometimes have some adjustments. I think it would be easier.
    Anyways, next time I should consider to only design PCB and send to some manufactures to do fabricating job.
    Thank you for your remind & being interest in my project.

    0
    None
    tuenhidiyfonosharaf

    Reply 14 days ago

    Yes, we can. If I had a bigger PCB prototype matching with 16x16 matrix size, for sure it will be better.

    0
    None
    LlewellynD1

    14 days ago

    WOW! Absolutely love PLC's and also Matrix Displays.
    This combination is fantastic, and so novel! A match made in Heaven, I'd say... LOL.
    Thanks for your effort in building, and information in sharing this.
    Most appreciated and best regards with future projects, similar or otherwise.

    Lew

    4 replies
    0
    None
    tuenhidiyLlewellynD1

    Reply 14 days ago

    Hi Lew,
    Thanks for encouraging me with this project. While working & visiting at some factories, I have seen some single color - big led matrices that display some production information, raw material consumption.... and it can be connected to the factory's PLC system through cables, like Profibus or Ethernet. They're very costly (some thousand USD). With my project, it's so cheap, colorful & can be connected via WIFI. I should try to show PLC information on a big RGB led matrix next time if I have one.

    0
    None
    LlewellynD1tuenhidiy

    Reply 14 days ago

    Fan-tastic! Please post again if/when possible, so we can enjoy/share great work like that...
    Rock on!
    Lew
    0
    None
    diy_bloke

    15 days ago

    Very interesting. After going through all your BAM links (and a Google search), do I understand correctly that BAM is just PWM but with only 16 levels?