What is the best signal interface for PC ?

_q12x_ · Jun 8, 2022

I mean.... the best and the easiest to use.
I remember back in the 2000's I used a serial interface, I think it was the printer serial port, 25 pins or similar. I believe I even used a mouse port as well, that versatile those systems were back then.
What I could do with it was ... program in C++ and pascal back then, using some imported dll's specific for communication with this serial port, I think it was port 40 or 25? It had a number is all I remember. And I could link to it any transistor base, back then I was working exclusively with BJT's, to light LED's, drive motors, beep some 8ohm I think they were speakers, drive a VU-meter LED bar I think directly from the port pins, without transistors, and also drive IC's , that was the time I learned about multiplexers and expanding the number of output pins. Also input sensors like LDR and buttons. I Loved that kind of easy and straight forward communication.
Today I dont know c++ or pascal anymore, but I am very good in c# and still use VS2010 because its very cool interface and very user friendly overall.
So I want you, to help me first of all, to find the hardware, the port I suppose or something more than a printer port, something more advanced and having more in/out's. The more the better. I want the best you can find for the moment. Best ideas or best adaptations, why not. As long as it's easy and stable to install and use.
And then, the software drivers and possible problems will appear along the way. I can debug a large majority of problems, I grow up debugging computer problems, so I have a 5'th sense for them. Im more concerned about the hardware part and the integration with my win7 that I still run today and my VisualStudio2010 for my c#. I know I still run old software but they are extremely stable and they don't f me up.
Thank you and I'm really curious what you will find for me.

_q12x_ · Aug 18, 2022

Exceptionally (for me) is to make it how you make it, only from logic chips like you are making it right now. And is terrible challenging for me to do it like you. But it is remained in my mind to do it like that as well. Not sure when exactly....

marconi · Aug 18, 2022

I will respond more completely when I have the time and energy and done some research on the 23017 and 23S17 ics.

For now, the period of a repetitive waveform is the inverse of its frequency. So a 100kHz waveform has a period of

1/100000 = 0.00001s or 10 microseconds. A micro second is 0.000001s - one millionth of a second.

_q12x_ · Aug 19, 2022

- If it helps, for mister @marconi, here is the datasheet for my MCP23017 that I have.
On the very first page you have a summary of what it can do.

https://ww1.microchip.com/downloads/en/devicedoc/20001952c.pdf

Very good math explanation. I like it. I dont do it every day so I tend to forget things. Shame of me. Im mixing colors more often than mixing numbers, haha. Get it? because im a poor artist.
- I start to contemplate the idea of using some faster IC's, like 74HC165 shift registers that @timhoward mentioned already, and most probably more hard to wire in hardware and also much harder to code. Just to have a secondary board. But not 100 I/O pads, just a few, maybe 20 or something. I also remember Teensy board had 40 IO's already and the best one with 58 IO's , which is VERY appealing and also using I2C protocol. Mister @timhoward can confirm it, if is still around.
- Is so disappointing that my Arduino Uno can Not go down under 1ms !!! Ahhhh what a stick in the hearth.
- Also yesterday I received my Arduino Nano board, the replacement for Arduino Uno, and the upgrade for this MCP board I built. I will show some pictures and movie later after I mount everything.

_q12x_ · Aug 19, 2022

To mister @timhoward if you are still around, can you do a test for me? check your maximum fv that you can get from 1 of your I/O from your Teensy board? And dont read it from its datasheet, but do it in reality and tell me if it stops to 1ms like my arduino uno does, or is actually capable to go down to μs(microseconds) ? Thank you !

marconi · Aug 19, 2022

q12 Good morning. To aid help me understand your programming could you slow the scan rate so far that I can see how you select an LED for illumination and post a short video. You can see from my video that I scan the LEDs column by column. In the video I have set the data word for each row as (1111111) so that all 7 LEDs in a column are lit when each of the 5 columns is selected. The data word for the columns follows the sequence (10000), (01000), (00100), (00010), (00001), (10000)......
Thus a sequence of 5 pairs of row and column data words, 10 data words in total, allows me to display any arrangement of LEDs on the display. I want to see what you do.

_q12x_ · Aug 19, 2022

Good morning , where are my manners, right? Hehe.
Remember, this what I do is software programming, but you do it much harder, in hardware !!! Keep this in mind all the time.
Hmmm.... hehe, here is a quick and dirty way of obtaining 1 single led on the matrix, following my already made example.
Just put 5V on pin 3 (with gray) - also dont forget to put resistors !!!! because you will burn the led !!!
and put 0V/ground on pin 11(with gray). Ive also marked with 3red arrows the positions where to put the voltages on which pins.
I will make a more comprehensive explanation for you, but it will take some time, also to make most probably a new drawing, and then the movie and edit it and upload it to yourtube. So until then, at least do this very quick and dirty example here and you will get a procentage of an idea.

[ElectriciansForums.net] What is the best signal interface for PC ?

_q12x_ · Aug 19, 2022

Still cryptic, isn't it?
I believe now I made it more clearer than before:

marconi · Aug 19, 2022

So do you select in software one LED at a time by setting one of the line bits and one of the column bits? And then send this data to the MCP23017? Thus to illuminate say all 35 LEDs you have to sequence through 35 pairs of line and column bits (Column, Line). Each data transfer to the MCP23017 has a cycle time Tc - I have yet to find out what this time is. Thus to refresh completely the 35 LEDs will take a time of 35 x Tc - this is the time necessary to send 35 pairs of (Line, Column) messages. This is a slow way to control the 7 x5 display. You could use the 16 bits data outputs in the format ( C1, C2, C3, C4, C5, X, X, X, L1, L2, L3, L4, L5, L6, L7, X) to illuminate a combination of 7 LEDs in one column using one data transfer, and thus the whole display in 5 data transfers - a considerable reduction in data transfer time from 35 Tc to 5 Tc. (The X means not used).

To do this you would have to add some simple hardware to the 7 x 5 display - some transistors and resistors to interpret the 16 bit data word into switches to control the application of 5V and 0V to the LED array. The scanning has to be done column by column to take advantage of the common cathode arrangement inside the array.

DPG · Aug 19, 2022

marconi said:
So do you select in software one LED at a time by setting one of the line bits and one of the column bits? And then send this data to the MCP23017? Thus to illuminate say all 35 LEDs you have to sequence through 35 pairs of line and column bits (Column, Line). Each data transfer to the MCP23017 has a cycle time Tc - I have yet to find out what this time is. Thus to refresh completely the 35 LEDs will take a time of 35 x Tc - this is the time necessary to send 35 pairs of (Line, Column) messages. This is a slow way to control the 7 x5 display. You could use the 16 bits data outputs in the format ( C1, C2, C3, C4, C5, X, X, X, L1, L2, L3, L4, L5, L6, L7, X) to illuminate a combination of 7 LEDs in one column using one data transfer, and thus the whole display in 5 data transfers - a considerable reduction in data transfer time from 35 Tc to 5 Tc. (The X means not used).

To do this you would have to add some simple hardware to the 7 x 5 display - some transistors and resistors to interpret the 16 bit data word into switches to control the application of 5V and 0V to the LED array. The scanning has to be done column by column to take advantage of the common cathode arrangement inside the array.

Multiplexing in that way is definitely the best way to do it I would say.

_q12x_ · Aug 19, 2022

marconi said:
So do you select in software one LED at a time by setting one of the line bits and one of the column bits? And then send this data to the MCP23017?

Exactly.
Here is the actual program for 'letter A' that I made and presented in the movie.
You may not understand everything but read the entire program anyway and you will get something out of it. I've also put notes what is line and what is column.
(it was imperative to switch to Input everything after each step, with my custom Reset(); method, otherwise it was liting up the entire next line or column)
Remember a line is HIGH because is +5V and a column is LOW because is 0V. So we lit a single line putting +5V on line01(for ex) and 0v on each desired column.

Code:

#include "Arduino.h"                    //core library that contains all of the Arduino’s built-in functions (from 2022)
#include <Adafruit_MCP23X17.h>          //this is Adafruit-MCP23017-Arduino-Library version 2.1.0
 
Adafruit_MCP23X17 mcp1; //Instantiate mcp1 object
 
void setup()
{
  Serial.begin(19200);
  mcp1.begin_I2C(0x20);
  for(int i = 0; i <= 15; i++)
  {
    mcp1.pinMode(i, INPUT);
  }
  for(int i = 0; i <=15; i++)
  {
    mcp1.digitalWrite(i, LOW);
  }


//LED MATRIX DISPLAY - Single LED - one by one
/*  LOGIC:
//Columns----------------------------------------
//  mcp1.digitalWrite(1, LOW); //A1=1=column A
//  mcp1.digitalWrite(10, LOW);//B1=10=column B

//  mcp1.digitalWrite(3, LOW); //A3=3=column C middle
//  mcp1.digitalWrite(11, LOW);//B2=11=column C middle

//  mcp1.digitalWrite(4, LOW); //A4=4=column D
//  mcp1.digitalWrite(13, LOW);//B6=13=column E

//Lines----------------------------------------
//  mcp1.digitalWrite(5, HIGH);//Line1
//  mcp1.digitalWrite(0, HIGH);//Line2
//  mcp1.digitalWrite(6, HIGH);//Line3

//  mcp1.digitalWrite(2, HIGH);//Line4
//  mcp1.digitalWrite(12, HIGH);//Line4

// mcp1.digitalWrite(8, HIGH);//Line5
//  mcp1.digitalWrite(14, HIGH);//Line6
//  mcp1.digitalWrite(9, HIGH);//Line7
*/

}

void Reset()
{
 for(int i = 0; i <=15; i++)
 {
   mcp1.pinMode(i, INPUT);
   mcp1.digitalWrite(i, LOW);
 }
}


int dly = 1;
void chr_A()
{
  //line1
 mcp1.pinMode(5, OUTPUT);   //line
 mcp1.digitalWrite(5, HIGH);
 mcp1.pinMode(10, OUTPUT);   //column
 mcp1.digitalWrite(10, LOW);
 mcp1.pinMode(3, OUTPUT);   //column
 mcp1.digitalWrite(3, LOW);
 mcp1.pinMode(4, OUTPUT);   //column
 mcp1.digitalWrite(4, LOW);
 delay(dly);
 Reset();
 
  //line2
 mcp1.pinMode(0, OUTPUT);   //line
 mcp1.digitalWrite(0, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();

  //line3
 mcp1.pinMode(6, OUTPUT);   //line
 mcp1.digitalWrite(6, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();

  //line4-midle
 mcp1.pinMode(2, OUTPUT);   //line
 mcp1.digitalWrite(2, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(10, OUTPUT);   //column
 mcp1.digitalWrite(10, LOW);
 mcp1.pinMode(3, OUTPUT);   //column
 mcp1.digitalWrite(3, LOW);
 mcp1.pinMode(4, OUTPUT);   //column
 mcp1.digitalWrite(4, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();

  //line5
 mcp1.pinMode(8, OUTPUT);   //line
 mcp1.digitalWrite(8, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();

  //line6
 mcp1.pinMode(14, OUTPUT);   //line
 mcp1.digitalWrite(14, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();

  //line7
 mcp1.pinMode(9, OUTPUT);   //line
 mcp1.digitalWrite(9, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();
 
}



void loop()
{
 chr_A();
}

marconi · Aug 19, 2022

Not read yet what you posted recently but this is the transistor and resistor hardware to interpret the 16 bit data word I mentioned earlier. The pnp transistor is a BC557B.

_q12x_ · Aug 19, 2022

You can use NPN as well. Depends what you have more.
Also dont forget each resistor to each matrix board pin !!! You should include resistors for each pin, in your circuit. 1k is good enough.
Also very important, make your circuit as logical and simple to follow as possible, as much intuitive you can make it. You really have to put your neurons to work for this part. I know for sure. It will pay up for you in the near future and for others that are reading your circuit.

marconi · Aug 19, 2022

Yes. I missed off the current limiting resistor in each of the pnp transistor collector - line ( row) paths.

_q12x_ · Aug 19, 2022

This led matrix pin number assignment is pretty much like a code.
All that I did was to 'decode' it into a human easy to understand and intuitive way of dialing.
If you remember in WW2 - the german made 'Enigma Machine' ? Pretty cool device. This was pretty similar to that. In my mind at least.
You basically have to link 7 positive (+5V) pins that will represent your lines and 5 negative (0V) pins that will represent your columns. All passing through transistors (whatever they are, doesn't matter) to be able to command each pin separately from your future hardware code.
You know what is interesting and relatively fast? to put buttons and press them all at once to get ...well, only 1 line at a time. pretty much like I did in my code at very low fv. Or simple mechanical switches !!! So --12-- in total.

marconi · Aug 19, 2022

You have it. The column Cn and line Ln (my row Rn) bits in the 16 bit data word at the output of the MCP2017 select the column and line transistor switches as on or off. This is done column by column as you see in my earlier video with all Ln set to logic O so all 7 LEDs in a column light up as a test.

marconi · Aug 20, 2022

q12x good afternoon to Romania. I have attached a short video of the eeprom programmer I made today which demonstrates the first five memory locations loaded with different test patterns for the 8 bit Line (my Row) data words - only 7 bits actually used. The top set of dip switches sets the data word to be stored and the lower set selects the address to store the data word. The small black button generates a pulse to tell the eeprom to store the data as detailed on the dip switches. I will build next some sequential logic counters to address the eeprom to retrieve a particular group of 5 L/R data words to drive the 7 x 5 LED display and produce the image I want. In my case the 16 letters a through to n for the earlier Gray Code project so there will be 16 groups of L/R data words.

The test patterns would display the third attachment - note drawn for 8 lines/rows.

Jim_Mc · Aug 20, 2022

Hi there,

Looks like you're using a single ATMEGA328 for each 16 LEDs? This is completely unnecessary. If the only requirement is to drive multiple LEDs in a sequence, then you could do this using a shift register, like in this example:

Shift Registers - 74HC595 & 74HC165 with Arduino

Learn to use the 74HC595 and 74HC156 shift registers to add extra input and output ports to your Arduino, then use them to build a fancy LED light display!

dronebotworkshop.com

You can get multiple shift registers, or shift registers with more parallel output pins to drive the number of LEDs which you need.

I believe you can even chain them to get more output.

This will be a) cheaper and b) more energy efficient than powering multiple 328p's.

_q12x_ · Aug 21, 2022

I reinstalled back my arduino Uno and everything is working as before.
But in my latest program that I made, I can obtain a diagonal line on a Led Dot Matrix as a test program, but its refresh rate can not be lower than 1ms as arduino is restricting. MCP chip is minimum 100kHz (actually has higher values specified) which means 10μs per cycle.
- Do anyone know how to lower arduino fv to μs instead of ms ?
In the movie here I present using it's internal fuction
delay(dly);
which is a ms function, I read about it and I get that. I tried also its other function as well, named
delayMicroseconds(dly);
and the result is exactly as the delay(dly); in ms and not under 1ms, to it's promoted μs.
This is a 2min video where I explain the entire problem, please watch it.
Thank you.

marconi · Aug 21, 2022

5x7 DOT Matrix - https://fontstruct.com/fontstructions/show/847768/5x7_dot_matrix

Today, I programmed the eeprom with the 7 x 5 fonts for the capital letters A to P. Now I will look at your latest video.

My initial reaction to the word 'delay' is that you may be using the wrong command. A delay is just that - it does something later than demanded. This may be your problem because the delay is slowing things down such as data transfers.. eg: The data transfers occur every 10 microseconds (say) and then you delay each transfer by 10milli seconds. The delay will dominate. But as I say I am not at all versed in the arduino you are using.

For most people a refresh rate of 50 to 100Hz fools the eye and brain to see a flicker free image as in a conventional TV picture - but modern TV's may do something different these days.

You could average over time the output in software to remove the flicker to make the output virtually constant until there is a change in output. Write a new sub-routine which takes your current sub-routines output as its input and produces an output which is flicker-free.

_q12x_ · Aug 21, 2022

marconi said:
For most people a refresh rate of 50 to 100Hz fools the eye and brain to see a flicker free image as in a conventional TV picture - but modern TV's may do something different these days.

100Hz not 100kHz! - VERY Interesting that you mention this! This is helpful. So my 1ms delay in code might not be a real 1ms at all. The speed in reality is probably somewhere at 20Hz now that I think about it. Hmmmm... very intriguing. They definitely have some issues on their I2C pins on that arduino board.
I just google a bit and I find and confirm with: "most humans can't easily distinguish individual frames at 30 hz."
The visible fast flickering is under 30Hz !
So the SCL pin from arduino is simply under 30Hz and not even close to 1ms which is 1000Hz. Hmmm, very interesting.

marconi · Aug 22, 2022

_q12x_ said:

Exactly.
Here is the actual program for 'letter A' that I made and presented in the movie.
You may not understand everything but read the entire program anyway and you will get something out of it. I've also put notes what is line and what is column.
(it was imperative to switch to Input everything after each step, with my custom Reset(); method, otherwise it was liting up the entire next line or column)
Remember a line is HIGH because is +5V and a column is LOW because is 0V. So we lit a single line putting +5V on line01(for ex) and 0v on each desired column.

Code:

#include "Arduino.h"                    //core library that contains all of the Arduino’s built-in functions (from 2022)
#include <Adafruit_MCP23X17.h>          //this is Adafruit-MCP23017-Arduino-Library version 2.1.0
 
Adafruit_MCP23X17 mcp1; //Instantiate mcp1 object
 
void setup()
{
  Serial.begin(19200);
  mcp1.begin_I2C(0x20);
  for(int i = 0; i <= 15; i++)
  {
    mcp1.pinMode(i, INPUT);
  }
  for(int i = 0; i <=15; i++)
  {
    mcp1.digitalWrite(i, LOW);
  }


//LED MATRIX DISPLAY - Single LED - one by one
/*  LOGIC:
//Columns----------------------------------------
//  mcp1.digitalWrite(1, LOW); //A1=1=column A
//  mcp1.digitalWrite(10, LOW);//B1=10=column B

//  mcp1.digitalWrite(3, LOW); //A3=3=column C middle
//  mcp1.digitalWrite(11, LOW);//B2=11=column C middle

//  mcp1.digitalWrite(4, LOW); //A4=4=column D
//  mcp1.digitalWrite(13, LOW);//B6=13=column E

//Lines----------------------------------------
//  mcp1.digitalWrite(5, HIGH);//Line1
//  mcp1.digitalWrite(0, HIGH);//Line2
//  mcp1.digitalWrite(6, HIGH);//Line3

//  mcp1.digitalWrite(2, HIGH);//Line4
//  mcp1.digitalWrite(12, HIGH);//Line4

// mcp1.digitalWrite(8, HIGH);//Line5
//  mcp1.digitalWrite(14, HIGH);//Line6
//  mcp1.digitalWrite(9, HIGH);//Line7
*/

}

void Reset()
{
 for(int i = 0; i <=15; i++)
 {
   mcp1.pinMode(i, INPUT);
   mcp1.digitalWrite(i, LOW);
 }
}


int dly = 1;
void chr_A()
{
  //line1
 mcp1.pinMode(5, OUTPUT);   //line
 mcp1.digitalWrite(5, HIGH);
 mcp1.pinMode(10, OUTPUT);   //column
 mcp1.digitalWrite(10, LOW);
 mcp1.pinMode(3, OUTPUT);   //column
 mcp1.digitalWrite(3, LOW);
 mcp1.pinMode(4, OUTPUT);   //column
 mcp1.digitalWrite(4, LOW);
 delay(dly);
 Reset();
 
  //line2
 mcp1.pinMode(0, OUTPUT);   //line
 mcp1.digitalWrite(0, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();

  //line3
 mcp1.pinMode(6, OUTPUT);   //line
 mcp1.digitalWrite(6, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();

  //line4-midle
 mcp1.pinMode(2, OUTPUT);   //line
 mcp1.digitalWrite(2, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(10, OUTPUT);   //column
 mcp1.digitalWrite(10, LOW);
 mcp1.pinMode(3, OUTPUT);   //column
 mcp1.digitalWrite(3, LOW);
 mcp1.pinMode(4, OUTPUT);   //column
 mcp1.digitalWrite(4, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();

  //line5
 mcp1.pinMode(8, OUTPUT);   //line
 mcp1.digitalWrite(8, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();

  //line6
 mcp1.pinMode(14, OUTPUT);   //line
 mcp1.digitalWrite(14, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();

  //line7
 mcp1.pinMode(9, OUTPUT);   //line
 mcp1.digitalWrite(9, HIGH);
 mcp1.pinMode(1, OUTPUT);   //column
 mcp1.digitalWrite(1, LOW);
 mcp1.pinMode(13, OUTPUT);   //column
 mcp1.digitalWrite(13, LOW);
 delay(dly);
 Reset();
 
}



void loop()
{
 chr_A();
}

I counted 7 one millisecond delays, one after the other in this sub-routine. I suppose for now that from the start to end of this sub-routine takes of the order 7mS. I cannot quickly work out if 7mS is to generate a single column of 7 LEDs, a single line of 5 LEDs or all 35 LEDs. Please check my analysis because I am pretty sure I have not completely understood your code. You understand how you have written the code so ought to be able to arrive at figure of about 30Hz or lower which you mentioned earlier.

If 7mS is for all 35 LEDs then the refresh rate is 1/0.007 = 140Hz.
If 7mS is for a column of 7 LEDs, and there are 5 columns the refresh rate is 140/5 = 28Hz.
If 7mS is for a line of 5 LEDs and their are 7 lines the refresh rate is 140/7 = 20Hz

Why do have delay command at all in this sub routine?

marconi · Aug 22, 2022

My progress so far. The eeprom addressed by sequential logic to find the five 7 bit data words to form the font for N. Refresh rate is about 200Hz ie A complete N two hundred times every second. Clock is 1kHz and 1000/5 = 200Hz where 5 is number of columns. And letter B too.

_q12x_ · Aug 22, 2022

Congratulations mister @marconi
Now put a movie with it and your comments !
I managed to optimize my code and now is less flicker that original. Its still a vibration but really almost not visible at all. I also installed a second mcp23017 library and all last night and until now today, I stay on it, but it has some very-very weird logic inside that I could only partially descypher. So no complete descypher at the moment of this second library that is promising greater potential, since is more close to a PIC program and also closer to our simplified schematic diagram. I literally hammer it last night, im very tired from it. But I learned some interesting stuff doing it, very technical and very in the programming domain. Just putting on the table what I did.

_q12x_ · Aug 22, 2022

_q12x_ · Aug 22, 2022

Good morning mister @marconi ,
Here is something interesting... Im not sure how much may have been influenced my program testing so far, I will have to make a more extensive research on this particular detail, but in time. For the momment, with the programs I run already, I didnt really observed much of a difference to be honest. But it crossed my mind that this little bugger might be important in some special cases, special programs. Time will tell.
So here it is - full view:

The blue lines represent the Ground or 0V. I marked with a square the 0V marking next to the metalic pad from which the wire is going beneath the cardboard to that long track on which, each negative pin for all the LEDs are connected. So what I have there is a pull down connection through each 12k resistor put in series to each LED to ground.

This problem I realize it yesterday, when I was programming and was meditating to the fact those pins from the IC are not really floating or inAir. I then realized they are actually pulled to ground through each led. And today, I mounted that little switch only between this rail for all the leds and 0V. I tested a couple of normal programs but no visible difference. Ill have to test some in depth programs that I have 'somewhere' that really needs some floating pins. I really hope it will be a difference this time. If not, then, daaaaeeem.