Led.Digits not working with my 8-Digit LED Display Segment

[idophir]

I've spent a few hours on this and I can't get my 8-Digit LED Display Module to work. No matter what character I try to draw or print it just prints random illegible characters or nothing.

I purchased my board in China but it works fine with the snippet below. What am I doing wrong?
Is there a way to send arduino code to the board from within the johnny-five project?

// Pin numbers
int rck = 4; // clock
int sck = 3; // cs
int dio = 2; // data

// Binary for 0 to 9
byte num[10]={B11000000, B11111001, B10100100, B10110000,
B10011001, B10010010, B10000010, B11111000, B10000000, B10011000};

// Positions
byte pos[8]={1, 2, 4, 8, 16, 32, 64, 128};

void setup() {
  pinMode(rck, OUTPUT);
  pinMode(sck, OUTPUT);
  pinMode(dio, OUTPUT);
}

void loop() {
  for (int j = 0; j < 8; j++) {
    digitalWrite(rck, LOW);
    shiftOut(dio, sck, MSBFIRST, pos[j]);
    shiftOut(dio, sck, MSBFIRST, num[j]);
    digitalWrite(rck, HIGH);  
    delay(2); // This keeps the flicker above 60 Hz
  }
}

[rwaldron]

Can you link me to the device you're using (so I can acquire one)?

[idophir]

Thanks for the quick reply.
This is where I purchased it from: https://item.taobao.com/item.htm?spm=a1z09.2.0.0.AGtr6h&id=14526509137&_u=q20t89f44be2

I currently live in China so it was very easy to get.
I have a feeling the display is expecting an 8-bit value while Led.Digits sends it a binary. Could that be the case?

[rwaldron]

No, that wouldn't be the case. I have several different 8 digit displays that have been tested with Johnny-Five, but not this exact unit. I'll figure out getting one of these, but in the meantime, can you give me two things?

1. Paste the exact code that's failing
2. Post a picture of your hardware

I'll do my best to help you as immediately as possible, but today is a holiday in the US and I will be AFK for the day in about an hour.

[idophir]

This code makes the display show "8." on the leftmost position.

var five = require("johnny-five");
var myBoard;
myBoard = new five.Board();

myBoard.on("ready", function() {
    var display = new five.Led.Digits({
        pins: {
            data: 2,
            cs: 3,
            clock: 4
        }
    });

    display.clear();
    display.draw(0, 1, 0x00);
});

Here is a picture of the display:

Thanks a lot for helping. Enjoy your holiday.

[rwaldron]

draw method is for matrix devices (long story about how they all came to have the same backing class). Try this instead:

display.print("88888888");

[rwaldron]

Also, need better docs :/

[idophir]

Well, something has changed - now I see the numbers light up for a very short time from left to right. It does that twice and then shows a constant dot on the rightmost digit...

[rwaldron]

Strange! I'm AFK now, but I can dig into this tomorrow—sorry for delaying your project :/

[dtex]

Hi @idophir ,

Johnny-Five contributors and maintainers are loathe to close issues where someone has a need. We don't want anyone to ever feel that we don't care, but we just haven't gotten to this feature yet. Rather than leave it languishing as an open issue we have created a Requested Features page and added your request for the 595 there.